NSCI 175 Exam 3

Psychotherapy for a Phobia

-Gradually increase exposure of patient to the stimuli that produce anxiety, reinforcing the notion that the stimuli are NOT dangerous. At the neurobiology level aim is to alter the connections in the brain such that real or imagined stimuli no longer evoke the stress response!

Stages of learning and memory

*Acquisition of short-term memory*- results from synapse modifications casued by incoming sensory info. *Consolidation of long-term memory*- Further changes like gene expression and protein synthesis allow for the short term memory to be consolidated into long term memory

CREB1 vs CREB2

*CREB1 promotes transcription* (needs to be phosphorylated) and if over-expressed leads to a "photographic" memory (learn a task in a single training rather than many) *CREB2 blocks transcription* (reverses gene expression, blocks memory consolidation and performance in simple memory tasks

REM on cells

--> cholinergic cells of the pons.

Composition of NMDA receptors

-4 subunits --2NR1 --2NR2 (ratio of NR2A and NR2B determines the properties of the receptor) *LTP favored with more NR2B because more calcium can pass through* *After high cortical activity and LTP, NR2A levels increase which promotes LTD and makes LTP harder to induce

2nd generation/ atypical antipsychotics

-Fewer side effects and also treat some of the negative symptoms- important (think about social functioning, holding a job); don't act via dopamine, but not clear exactly where they do act; good evidence for serotonin

Anterior Cingulate Cortex Dysfunction

-Functional brain imaging studies have consistently found increased resting-state metabolic activity in the anterior cingulate cortex of depressed patients. -This region of the brain is considered to be a "node" in an extensive network of interconnected structures

Biological bases of anxiety disorders

-Genetic predisposition for many anxiety disorders -Fear evoked by threatening stimulus: stressor (real threat or imagined threat) --Manifested by stress response --Stimulus-response relationship strengthened (or weakened) by experience -Stress response --Humoral response: corticotropin-releasing hormone (CRH) --> adrenocorticotropic hormone (ACTH) --> cortisol

Zeitgebers

-German for "time givers" -Environmental time cues -For mammals: primarily light-dark cycle

5 Tips for a better night's sleep

-Make it dark! (limit screen time, wear a mask, etc.) -Regularity (go to bed and wake up at the same time) -Keep it cool at night (65 to 68°F) -Don't stay in your bed awake (associative brain) -No Caffeine (post 2 pm) or night caps (alcohol)

Other structures involved with anger

-Many other structures (not just the amygdala) are thought to be involved with anger and aggression -fMRI studies in humans à orbitofrontal cortex and anterior cingulate cortex (when individuals remember events that made them angry)

Persistently Active Kinases: CAMKII

-activated by calcium -Autophosphorylating kinase -Keeps AMPA receptors phosphorylated- Maintenance of synaptic potentiation -Molecular switch hypothesis: autophosphorylating kinase can store info at the synapse -HINGY MOLECULE, Hinge opens with Ca2+

The pharmacological and genetic studies show that hippocampal NMDA receptors play a key role not only in synaptic modification, such as LTP and LTD, but also in _______________.

Learning and Memory

What protein is encoded by the ob gene?

Leptin

Oxycotin

Neurohormone that controls lactation, suppress hypothalamic function, "love" hormone -Released by the magnocellular neurosecratory cells of the hypothalamus

Visceromotor response

Neurons in the hypothalamus respond to sensory signals by adjusting the balance of sympathetic and parasympathetic outputs of the autonomic nervous system (ANS)

Skills Learning

Nondeclarative memory of how to do something -Basal ganglia, motor cortex, and cerebellum involved

Conditioning

Nondeclarative memory where you respond to a stimulus because you associate it with something else -Cerebellum

Priming

Nondeclartive memory where you are more likely to use a word you heard recently -Cortex

Graceful Degredation

Representations blend together as neurons are lost, such that one memory gets confused with another

Anterior thalamus lesions lead to...

Spontaneous laughing or crying

Learning

The acquisition of new knowledge or skills

Which part of the pituitary (anterior or posterior) is considered a true endocrince gland? Why?

The anterior lobe of the pituitary is an actual gland. The cells of the anterior lobe synthesize and secrete a wide range of hormones that regulate secretions from other glands throughout the body.

The Periventricular Zone of the Hypothalamus Controls...

The autonomic nervous system (ANS)

1)Stimulation of the LH _______ feeding behavior

Triggers

True or False: All of the autonomic nervous system EXCEPT the post-ganglionic sympathetic neurons release ACh

True

True or False: Increases (LTP) and decreases (LTD) in synaptic strength contribute to the formation of declarative memories.

True

True or False: Negative feedback systems are the primary homeostatic mechanisms

True

True or False: The cell bodies of all autonomic lower motor neurons lie outside the central nervous system, within cell clusters called autonomic ganglia. -The neurons in these ganglia are called postganglionic neurons.

True

True or False: There is potentially a link between cannabis use and schizophrenia

True

True or False: kappa opiate receptors are normally activated during a stressful experience and contribute directly to the initiation of drug-seeking behavior in animals, and perhaps to relapse in humans.

True

True or False: Projections to motor neurons in the spinal cord inhibit movement during sleep

True, but small lesions ventral to the locus coeruleus prevent the loss of muscle tone during REM sleep. -Cats with such lesions seem to act out their dreams. -REM sleep disorder is commonly observed in Parkinson's Disease and often begins before diagnosis -Locus coeruleus neurons degenerate very early in Parkinson's Disease

Theta waves

brain waves indicating the early stages of sleep Theta: 4-7 Hz, some sleep and waking states

Diffuse Modulatory Systems Critical to Control Sleep

1)Neurons MOST critical to control of sleep and wake are part of the diffuse modulatory neurotransmitter systems 2)5-HT & NE neurons fire during & enhance wake; Different ACh neurons enhance REM sleep while others enhance awake states 3)Systems control the rhythmic firing of thalamus which controls EEG rhythms of cortex (slow rhythms of sleep in thalamus block sensory information from reaching the cortex!) 4)Descending branches of these systems inhibit motor neurons during dreaming!

Non-REM sleep

1)Transitional sleep (few minutes & lightest) 2)Slightly deeper 5-15min sleep spindles & K complex 3)Delta rhythms, deeper sleep 4)Deepest sleep! 20-40 min (slow large amplitude delta waves!)

Post-traumatic stress disorder

An anxiety disorder characterized by haunting memories, nightmares, social withdrawal, jumpy anxiety, irritability, emotional numbness and/or insomnia that lingers for four weeks or more after a traumatic experience

Obsessive-compulsive disorder

An anxiety disorder characterized by unwanted repetitive thoughts (obsession) and/ or actions (compulsions).

Panic Disorder

An anxiety disorder marked by unpredictable minutes-long episodes of intense dread in which a person experiences terror and accompanying chest pain, choking, or other frightening sensations.

Diseases linked with lack of sleep:

Diabetes, Cardiovascular Disease, Obesity, Depression, Anxiety Disorders, Alzheimer's disease

Anorectic peptides do what?

Diminish appetite

Which neurotransmitter system do typical (1st generation) antipsychotics act on?

Dopamine

What happens in dopamine depleted animals

Dopamine-depleted animals "like" food but do not "want" food. -Lack motivation to seek food but enjoy it when available

Mesocorticolimbic dopamine system

Dopaminergic projection from midbrain that is important for reward -Dopamine release in the brain will reinforce the behavior that causes it.

REM off cells

= LC and raphe firing increases just before the end of REM sleep and go back down

Medial Temporal Lobes

Important for consolidation and storage of declarative memories Demonstrated by: -Electrical stimulation in the temporal lobe -Neural recordings from the temporal lobe

Leptin Depletion...

Incites adaptive responses to fight starvation

What do predict may occur if we stimulate the amygdala?

Increased vigilance, fear, and agression

Alpha waves

slow brain waves of a relaxed, awake state Alpha: 8-13 Hz, quiet, waking state

Beta waves

smaller and faster brain waves, typically indicating mental activity Beta: 15-30 Hz, activated or attentive cortex

Delta waves

the large, slow brain waves associated with deep sleep Delta: less than 4 Hz, deep sleep -Deep sleep: high synchrony, high EEG amplitude

Amygdala

two lima bean-sized neural clusters in the limbic system; linked to emotion. -The amygdala seems critical for emotion of fear -Other brain structures also involved in fear -Amygdala active also in other emotional states -Synaptic changes in the amygdala are involved in forming memories for emotional events.

Medial preoptic area of the hypothalamus stimulation leads to...

Social attraction

Autonomic Nervous System

(controlled neutrally by the hypothalamus). It has extensive interconnections within the body, the ANS simultaneously controls the responses of many internal organs, blood vessels, and glands.

Long-term Potentiation: CA1

-A long lasting enhancement of the effectiveness of synaptic transmission that follows certain types of the conditioning stimulus -High-frequency electrical stimulation to the Schaffer collateral axons produces LTP in CA1 neurons -Coactive synapses must cooperate to produce enough depolarization to cause LTP

Schizophrenia

-A severe psychiatric disorder characterized by delusions, hallucinations, and bizarre behavior

Fear Conditioning

-A type of classical or Pavlovian conditioning in which the conditioned stimulus (CS) is associated with an aversive unconditioned stimulus (US), such as a foot shock. As a consequence of learning, the CS comes to evoke fear. The phenomenon is thought to be involved in the development of anxiety disorders in humans. -Neurons in the central amygdala respond to the shock related tone! -Amygdala lesions eliminate the learned visceral responses (blood pressure, heart rate) -US = Shock -UR = Freezing & increase in blood pressure -CS = tone -CR = Freezing & increase in blood pressure

Classical Conditioning (Pavlov)

-A type of learning in which one learns to link two or more stimuli and anticipate events -US = food -UR = salivation -CS = bell -CR = salivation

REM Sleep

-Active hallucinating brain in paralyzed body -Antonia (loss of muscle tone) -Beta and gamma rhythms -Fast, low amplitude EEG -Paradoxical sleep -Rapid eye movement -Sympathetic activation -Vivid dreaming

Caffeine

-Adenosine receptor antagonist -Adenosine builds up the longer you are awake, builds sleep pressure -Caffeine Blocks sleep pressure -But once caffeine wears off, the adenosine has continued to build and sleepiness returns with a vengeance -Adenosine inhibits Ach, NE and 5HT systems

Discuss evidence that genes and environmental factors contribute to the development of schizophrenia

-Age of onset: Average age of onset is late teens/early 20s -Males have an earlier age of onset than females & have more severe symptoms/cases -We see that bump later in life in females not males because estrogen = protective; -We see a bump postmenopausal (less estrogen); (women on estrogen/hormone replacement therapy -> less likelihood)

Describe what constitutes an EEG signal- which neurons, what kind of activity?

-Amplitude of the EEG signal a measure of synchronous activity of underlying neurons -Measurement of generalized activity (of MANY neurons, not single neurons) of cerebral cortex -Helps diagnose neurological conditions, such as epilepsy and sleep disorders, and for research -an EEG measures voltages generated by the currents that flow during synaptic excitation of the dendrites of many pyramidal neurons in the cerebral cortex -many thousands of underlying neurons, activated together, to generate an EEG signal big enough to be measured at all

How is the amigdala impacted by sleep deprivation?

-Amygdala heightened response to negative stimuli -May result in expression of irritability, anger, aggression, emotionality, etc -Reduces the ability of pre-frontal cortex to suppress activity in amygdala

The amygdala ______ the HPA axis while the hippocampus _______ the HPA axis

-Amygdala projects to bed nucleus of the stria terminalis, which *activates* the HPA axis. Hippocampus *deactivates* the HPA axis. -Glucocorticoid receptors -Feedback loop

Associative Learning

-Behavior altered by formation of associations between events (In contrast to changed response to a single stimulus) -Classical conditioning and Operant learning

The Basics Functions of the Hippocampal System

-Binds sensory information for memory consolidation -Supports spatial memory of the location of objects of behavioral importance -Involved in the storage of memories for some length of times

Drugs that try to block cravings can...

-Boost inhibitory input onto the VTA dopamine neurons so they don't fire & release that dopamine into the NAc -Block the dopamine receptors in the NAc directly

Describe treatments for schizophrenia

-CBT can challenge thoughts (challenge the hallucination for e.g.); family therapy can help with EE and provide a support system for the patient; social skills help the patient integrate into society and become higher functioning; need this in addition to medication -Meds

Propose at least one practical implication of reconsolidation

-Can impact eyewitness testimony and treatment of stress associated with unpleasant memories -Loftus and Palmer --Speed estimates were impacted by wording

Esketamine

-Can relieve symptoms of depression in hours instead of weeks! -Especially important for suicidal patients -Ketamine is an anesthetic and party drug (Special K) -First new drug for depression in decades!

Consider how structural plasticity contributes to learning and memory

-Certain connections are strengthened, others are lost -Memory results from synaptic modifications -Neurons that wire together fire together

Consequences of chronic stress

-Chronic stress stimulates cortisol release from the adrenal gland which stimulates stimulates glucocorticoid receptors and degeneration of hippocampal neurons -In baboons: Gastric ulcers, colitis, enlarged adrenal glands, extensive degeneration of neurons in the hippocampus -In humans: combat, sexual abuse --PTSD heightened anxiety, memory disturbances, degeneration in hippocampus, overactivity of the amygdala

The role of the hippocampus

-Critical for memory consolidation of facts and events (HM) -Important for spatial memory (rat mazes) -Selectivity for people or objects we are familiar with (Hallie Barrie Neurons) -Form associations between sensory stimuli even when the information is not about space -"What happened, where"

Neural Mechanisms of Sleep

-Critical neurons --> diffuse modulatory neurotransmitter systems -Noradrenergic and serotoninergic neurons: fire during and enhance waking state -Cholinergic neurons: Some fire to enhance REM sleep events, while others fire during waking. -These diffuse modulatory systems control the rhythmic firing of thalamus --> controls cortical EEG. Remember sensory input to the cortex is blocked by slow thalamic rhythms during sleep. This way we can ignore our environment and get some rest.

Habituation

-Decreasing responsiveness with repeated stimulation/ learning to ignore a stimulus that lacks meaning -Ex. In a big city you quickly become habituated to sound of cars going by, the noise of the city, etc.

SM

-Did not recognize scared faces as afraid -S.M. could recognize fear from a person's tone of voice. It appears that the amygdala lesion selectively decreased her ability to recognize fear in faces from visual input alone.

Hypothalamus controls...

-Feeding (Leptin, AgRP, NPY, etc.) Stress (CRH & ACTH) -Mating (oxytocin) -Childbirth & lactation (oxytocin) -Aggression -Blood volume (vasopressin) -Social attraction & Reproduction -Temperature regulation -Reproductive development -Growth -Circadian rhythms

Procedural Memory and the Striatum

-Different memory types involve different brain structures -The striatum is involved in habit learning and procedural memory -Caudate nucleus + putamen = striatum -Key location in the motor loop --input from the frontal and parietal cortex --Output to thalamic nuclei and cortical areas involved in movement *Lesions in the striatum disrupt procedural memory (habit learning) but not declarative memory)*

Altzheimer's disease and Sleep

-Disrupted Sleep is a risk factor for Alzheimer's disease & an early symptom •Tau & Aβ accumulate in Alzheimer's disease Much of the brain's self-cleaning of these proteins by its lymphatic system occurs during sleep. -Decreased sleep = increased tau earlier in life

Explain the problems with the idea that there is a single system for emotions

-Diversity of emotions & different brain activity with each → NO reason to think there is only 1 system -Some structures involved in emotion are also involved in other functions → hypothalamus -NOT a one-to-one relationship between structure and function

Endorphins

-Endogenous opioids are endorphins (enkephalins) small peptides -Endorphins can suppress release of glutamate from presynaptic terminals, inhibit neurons by hyperpolarizing postsynaptic membranes

Multiple Trace Model of Memory Consolidation

-Engrams involve neocortex, but even old memories can also involve the hippocampus -Multiple memory traces -Each time a memory is retrieved, it occurs in new context with different sensory input creating a new memory trace

Partial activation of a memory trace may stimulate memory

-External events are represented in cortical cells. -Cells reciprocally interconnected -> reverberation -Simultaneously active neurons—cell assembly

Describe the procedure for producing learned fear

-Fear conditioning -After conditioning, however, neurons in the central nucleus of the amygdala responded to the shock-related tone (but not the benign one). -Pathway: somatosensory and auditory cortex --> central cortex --> Hypothalamus (autonomic response), PAG (Behavior), Cerebral Cortex (emotion)

Describe the experimental evidence that supports the SCN as a biological clock

-Hamster experiments -The key finding was that hamsters receiving transplants adopted the circadian rhythm of the transplanted SCN, not the rhythm they were born with. -A hamster's normal preference is to be active at night, but most tau animals could not completely entrain to the 24-hour rhythm. Instead, they found their activity periods continually shifting through various parts of the light-dark cycle.

Non-Rem Sleep

-High voltage, slow EEG -Dull or absent sensation -Logical, repetitive, occasional, involuntary thoughts and movements -Delta rhythms

HPA Axis and Depression

-Hospitalized patients with depression show high levels of cortisol -Cortisol feedback loop is disrupted in depressed patients! •Decreased numbers of glucocorticoid receptors •# of receptors is influenced by early life experiences (rats & maternal care)

You are working in a lab and have created genetically engineered mice that overexpress CRH. You hypothesize these mice will show

-INCREASED anxiety- like behaviors (When receptors for CRH are knocked out in mice --> less anxiety like behaviors)

Nondeclarative memory

-Implicit Memory -Motor skills, habits, classically conditioned reflexes -A type of nondeclarative memory -Involves learning a motor response ---In reaction to sensory input -Occurs in two categories of learning ---Nonassociative learning. (single stimulus) ---Associative learning

Describe at least two pieces of experimental evidence that support the idea that the MTL supports declarative memory

-In addition to the HM lesion studies... -Electrical stimulation and neural recordings from the MTL indicate this region is important for declarative memory! --Temporal lobe stimulation -----Effects different from stimulation of other areas of neocortex --Penfield's experiments -----Stimulation -> sensations like hallucinations or recalling past experiences --Temporal lobe: apparent role in memory storage Caveat: complex sensations reported by minority of patients, all with a need for brain surgery (epilepsy)

Standard Model of Memory Consolidation

-Information from neocortex areas associated with sensory systems sent to medial temporal lobe for processing -Synaptic consolidation, systems consolidation -Before systems consolidation hippocampus required but after consolidation it is not

Describe the evidence that LTP and LTD are involved with memory

-Inserting stimulating and recording electrodes in the hippocampus and using them to monitor the stat of synaptic transmission during learning -Use inhibitory avoidance to see how neuronal patterns change when something is learned -NMDA receptor blockers used while learning is attempted -Knockout mice for CA1 region after 3 weeks of life -Increased NMDA receptors led to increased learning ability

Hebb Networks and Memory Engrams

-It can be widely distributed among the connections that link the cells of an assembly -It can involve the same neurons that are involved in sensation and perception -Activation of some of the cortical cells via sensory input (maybe just the smell of the rose) within a cell assembly, then these cells are reciprocally interconnected with others involved with the memory to stimulate the perception of that event

Name some key, real experiments that support the role of the suprachiasmatic nucleus (SCN) as a biological clock?

-Lesions of the SCN abolishes Circadian rhythms in monkeys -SCN stimulation shifts circadian rhythms -Transplantations of a new SCN into a lesioned animal can restore rhythms (tau gene)

Liking vs Wanting

-Liking --> present moment, interoceptive sensation of well-being or homeostatic satisfaction, hedonic -Wanting --> future prediction of the outcome of liking, motivation seeking

Lifestyle factors that help reduce cognitive decline

-Living in a favorable environment -Involvement in complex and intellectually stimulating activities (25% increase in synapses) -Exercise

Awake State

-Low voltage, fast EEG -Vivid externally generated, logical progressive, continuous voluntary thoughts and movement -Alpha, beta, gamma rhythms

REM sleep

-Low voltage, fast EEG -Vivid, internally generated, logical, bizarre thoughts -Muscle paralysis, movement commanded by the brain but not carried out

Diathesis-Stress Hypothesis

-Mood disorders run in families (genetic component the predisposes us to this type of mental illness) -Diathesis → medical term for predisposition for a certain disease -Exaggerated activity of the HPA system associated with anxiety disorders -Indeed, one of the most robust findings in all of biological psychiatry is hyperactivity of the HPA axis in severely depressed patients: Blood cortisol levels are elevated, as is the concentration of CRH in the cerebrospinal fluid

Neuronal responses to visual stimuli

-Neurons in the IT cortex are highly selective for different faces -Neuronal patterns change with repeated presentation to become more or less responsive

Delayed Non-Match to Sample (DNMS) Task

-Normal monkeys are very good at this task & correctly displace the non-matching stimulus on about 90% of trials! -How will the performance of this task change in a MTL lesioned monkey as the length of delay increases?

Autonomic Nervous System response to stress

-Periventricular Hypothalamus activates the sympathetic ANS in stressful situations! -Sympathetic division: "fight or flight" -Increased heart rate and blood pressure -Depressed digestive function -Mobilized glucose reserves **slowwwww

Weak and Strong stimulation for LTP consolidation

-Persistence of LTP depends on whether synaptic stimulation is strong enough to trigger protein synthesis in the postsynaptic neuron -Weak stimulus induces LTP of the EPSP that rapidly decays -Strong stimulus soon after the weak stimulus causes protein synthesis that converts a temporary synaptic change into a lasting one

Persistently Active Kinases: PKMzeta

-Phosphorylates proteins that regulate AMPA receptor numbers -Phosphorylates proteins that regulate mRNA translation -Stays on long after Calcium -Translation of the kinase mRNA is activated by Calcium -ZIP specifically inhibits the kinase *Zip zaps memories (can erase LTP and established memories up to a long time after learning)*

Why is phosphorylation of proteins as a long-term memory consolidation mechanism problematic?

-Phosphorylation insufficient as a long-term memory consolidation mechanism --Phosphorylation of a protein is not permenant (so memories would be erased) --Protein molecules are not permenant Need other mechanisms for long term consolidation such as protein kinases and synthesis

Spatial Memory and Place Cells

-Place cells fire when an animal is in a specific place. -Place fields are dynamic --Develops new place cells when you enter new areas -Place cells are in the hippocampus -Based at least partially on visual input -Related to where the animal thinks it is -Found in humans with PET imaging (London Taxi Drivers)

Negative Symptoms of Schizophrenia

-Reflect the absence of responses that are normally present. These symptoms include: •Reduced expression of emotion •Poverty of speech •Difficulty in initiating goal-directed behavior •Memory impairment

Positive Symptoms fo Schizophrenia

-Reflect the presence of abnormal thoughts and behaviors, such as: •Delusions •Hallucinations- the most common are auditory hallucinations (i.e. hearing voices) •Disorganized speech •Grossly disorganized or catatonic behavior

Instrumental (Operant) conditioning

-Reinforcement of a subject for making a correct response that leads either to receipt of something rewarding or to escape from something unpleasant -Type of associative learning -In operant conditioning, the animal is operating on its environment. Its an active player. (not the case for fear conditioning where the animal is shocked regardless of what it does) --Ex. Mouse presses lever for cocaine

Melatonin

-Released when the environment darkens -Release inhibited by light! -Like the organizer of a race, helps get all of the players ready and then fires the starter pistol. (initiating sleep) -Most helpful for jet lag or older adults with low secretion levels

Working Memory vs Short term Memory

-Remember working memory is information that is "held in mind" like a phone number (working on the order of seconds). Working memory might be converted into long term but most of it is discarded when no longer needed -Short term memories are held on the order of hours. Working memory is distinguished from short term memory by tht every limited capacity ,need for repetition, short duration.

HM

-Removal of temporal lobes had no effect on perception, intelligence, personality. -Anterograde amnesia so profound he could not perform basic human activities (and partial retrograde amnesia) -He could not recognize the doctor who studied him for nearly 50 years. -Impaired declarative memory, but spared procedural memory (mirror drawing) -Told us Medial temporal lobe is critical for memory consolidation

What elicits sham rage

-Removal of the cerebral hemisphere but not hypothalamus -Removal of the cerebral hemispheres and the anterior hypothalamus

What are some rhythmic activities of the brain and how do we measure them?

-Sleeping and waking, hibernation, breathing, walking, electrical rhythms of cerebral cortex -Cerebral cortex: range of electrical rhythms correlated with interesting behaviors -EEG: classical method of recording brain rhythms, essential for studying sleep -Circadian rhythms: changes in physiological functions according to brain clock

Transient Global Amnesia

-Sudden onset of anterograde amnesia -Lasts a shorter period, from temporary ischemia (e.g., severe blow to head) -Symptoms: disoriented, ask same questions repeatedly; attacks subside in couple of hours; permanent memory gap

Drug that inhibits the HDAC2 (histone deacetylase 2) enzyme

-Switches neuroplasticity on and off -Can be administered while traumatic experience memories are reactivated to get rid of the memory --Extinction Therapy

Describe how the HPA axis is regulated by the amygdala and the hippocampus

-The CRH neurons of the hypothalamus are regulated by two structures: amygdala and hippocampus -Sensory information in through basolateral amygdala --> information sent to central nucleus and activation of this nucleus --> BNST --> stress response -Inappropriate activation of the amygdala seen in fMRI has been associated with some anxiety disorders

Declarative Memory

-The cognitive information retrieved from explicit memory; knowledge that can be declared -Explicit facts and events -Working memory. (we won't discuss in too much detail but will mention in memory 2) ---Temporary storage, lasting seconds -Short-term memories—vulnerable to disruption ---Facts and events stored in short-term memory ---Subset are converted to long-term memories. -Long-term memories ---Recalled months or years later

Interaction of the hypothalamus and homeostasis

-The hypothalamus integrates somatic and visceral responses in accordance with the needs of the brain. -A tiny lesion in the hypothalamus can produce dramatic and often fatal disruptions of widely dispersed bodily functions. -Temperature sensitive cells in the hypothalamus detect changes in brain temperature and orchestrate the appropriate responses

Monoamine hypothesis

-The hypothesis that mood is closely tied to the levels of released "monoamine" neurotransmitters— norepinephrine and/or serotonin—in the brain. -According to this idea, depression is a consequence of a deficit in one of these diffuse modulatory systems

What stimulates inappropriate stress?

-Too much amygdala activity -Too little hippocampal activity

Simple Neural Network: Selectivity

-Transformation from unfamiliar to familiar is due to the adjustment in the strengths of the synaptic input from different cells, all of which converge to cortical neurons --The more neurons in the network, the more unique memories an be stored and more resistant they are to damage to individual neurons -----Distributed memory

SSRIs

-Treat depression -Take 2-3 weeks to work -SSRIs are selective serotonin reuptake inhibitors. They block the serotonin transporter causing increased levels of serotonin in the synapse

Heroin and Nicotine

-VTA dopamine neurons have opiate and nicotinic acetylcholine receptors! -These drugs stimulate VTA neurons causing DA release in the NAc

Papez circuit (limbic system)

-connection of hypothalamus to/from cortex (older name of limbic system) *A network and a circuit; every emotion goes through this ring of the limbic system -Not a single discrete emotion system -emotions are based on distributed networks of brain activity!

Testosterone and agression

-in male mice, precastration testosterone is circulating and aggressive behavior (i.e. biting attacks) are elevated -Post castration, testosterone is NO longer circulating and aggressive behavior in MICE decreases substantially -In female mice, elimination of hormones produced by the ovaries (removal of the ovaries - ovariectomy) does NOT change biting attacks or aggression *increased testosterone = increased aggression*

Hypothalamo-pituitary portal circulation

-network of tiny blood vessels that run down the stalk of the pituitary and branch in the anterior lobe

LTP Molecular Mechanisms

1. Glutamate is released from the presynaptic neuron 2. Glutamate acts on the AMPA receptors to depolarize the postsynaptic neuron (entering Na+) 3. Depolarization of the post-synaptic neurons allows for the opening of the voltage-gated NMDA receptor. Specifically depol leads to the release of Mg2+ and activation of the NMDA receptor 4. Subsequent glutamate release will then activate AMPA and NMDA receptors -Spatial: enough to depolarize AND Temporal: subsequent depolarization -Increased Ca2+ in post-synaptic neuron activates kinases which phosphorylate other proteins leading to LTP by increased effectiveness of AMPA receptors and creation of more AMPA receptors

The Four Functions of Sleep

1.Energy conservation 2.Niche adaptation 3.Body restoration 4.Memory consolidation

LH (luteinizing hormone)

A hormone that causes maturation of the testes and ovaries -Targets Gonads

The Suprachiasmatic Nucleus (SCN)

A pair of cell clusters in the hypothalamus that controls circadian rhythm. In response to light, the SCN causes the pineal gland to adjust melatonin production, thus modifying our feelings of sleepiness -Intact SCN produces rhythmic message: SCN cell firing rate varies with circadian rhythm. -Retinal input necessary to entrain sleep cycles to night

Sleep

A readily reversible state of reduced responsiveness to, and interaction with, the environment -Universal among higher vertebrates -One-third of our lives spent in sleep state

Shorter sleep predicts...

A shorter life

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times. -25% of the general population has narcoleptic form of HLA gene, yet the majority don't develop narcolepsy. (Genes & Environmental Stressors play a role) -Do not go through SWS before REM sleep. -May show cataplexy—a sudden loss of muscle tone, leading to collapse.

Preganglionic neurotransmitters

ACh binds to nAChR, evokes fast EPSP. Ganglionic ACh activates mAChR, causes slow EPSPs and IPSPs. Some preganglionic terminals release NPY, VIP— trigger small EPSPs.

Increased firing rates in which systems likely support the transition from sleep to wake?

Acetylcholine (basal forebrain), Norepinephrine (locus coeruleus), Serotonin (raphe), Histamine (midbrain)

Serotonin deficiency hypothesis

Aggression is inversely related to serotonergic activity -Serotonergic raphe neurons project to the hypothalamus and limbic structures via the medial forebrain bundle.

Amygdala lesion leads to...

Amygdala lesion = less aggression •Disrupt social hierarchy (top monkeys will fall to the bottom of the hierarchy) •Reduced aggressive behavior for humans •Relief from anxiety •Profound, unpleasant side effects (blunting of emotional responses & loss of emotional component of thoughts, attention deficits, inappropriate behavior)

Protein Kinase

An enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein. -Phosphorylation that supports LTP is maintained when kinases stay "on"

Anterograde Amnesia

An inability to form new memories after brain trauma

Sensitization

An increase in behavioral response after exposure to a stimulus -Ex: You live in a busy city where horns honk all the time and don't get much reaction out of you. A few hours ago you were in a car accident and now any horn honk startles you tremendously

Articulate the difference between anger and aggression

Anger is a basic emotion. Many things can make us angry: frustration, hurt feelings, stress, and so on. Aggression is not an emotion but is one possible behavioral result of anger; an angry drunk might punch someone in the nose

Agoraphobia

Anxiety about being in places or situations from which escape might be difficult or embarrassing in the event of a panic attack

Anabolism

Assembly of macromolecules such as glycogen and triglycerides from simple precursors. (energy stores replenished during and immediately after a meal)

Inhibitory avoidance

Association of place with an aversive experience. Changes in synaptic transmission at the Schaffer collateral-CA1 synapses! Increases in EPSP = LTP.

Generalized Anxiety Disorder (GAD)

At least six months of persistent and excessive anxiety and worry

VMHv1-ventral stimulation leads to...

Attack

Name the two major classes of drugs used to treat anxiety disorders

Benzodiazepines = target the GABA A recepetor (chloride channel) resulting in sedative, hypnotic (sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, and muscle relaxant properties. -Allosteric effect SSRIs = target the Serotonin transporter (SERT) -Effects develop slowly over weeks -Changes that occur with chronic SSRI treatment that may or may not underlie antidepressant effects→ BDNF, neurogenesis, increase in glucocorticoid receptors in hippocampus, modulation of the serotonin system, etc.

Naloxon

Blocks opioid receptors (antagonist) -Used in opioid overdoses to counteract depression of central nervous system

Postabsorptive state—catabolism

Breaking down complex macromolecules for energy

Catabolism

Breaking down complex macromolecules. (during fasting conditions between meals. Stored glycogen & triglycerides are broken down to provide glucose for cellular metabolism)

Secretory Hypothalamus

By secreting chemicals directly into the bloodstream, the secretory hypothalamus can influence functions throughout both the brain and the body

CREB and Protein Synthesis

CREB1 is a transcription factor and CREB 2 Blocks transcription *Protein synthesis inhibitors block LTM consolidation* -Animals learn normally but cannot remember days later if inhibitors are injected shortly after training -New protein synthesis is important during periods of memory consolidation (STM -> LTM)

Hormones and release points for the HPA Axis

CRH (corticotropin releasing hormone) is released by parvocellular cells in the hypothalamus --> ACTH is released from anterior pituitary --> ACTH acts on the adrenal medulla above your kidneys to cause release of cortisol --> cortisol works throughout the body to mobilize energy stores and suppress your immune system and trigger your stress response.

Name the three phases that occur during short-term regulation of feeding

Cephalic, gastric, substrate

Given what you know about structural differences and cognitive symptoms of schizophrenia, what do you expect to see in terms of brain function?

Decreased activity in dlPFC (dorsolateral prefrontal cortex)

Cocaine

Cocaine is a strong inhibitor of the dopamine transporter (DAT). By inhibiting dopamine reuptake, cocaine ultimately causes an increase in the extracellular synaptic levels of DA. (i.e. an increase in DA found in the synaptic cleft)

FSH (follicle stimulating hormone)

Controls development of ovarian follicles, and sperm production -Targets Gonads

Diagram the neural circuit for anger and aggression

Cortex -> amygdala -> hypothalamus -> PAG & VTA -> aggressive behavior

Cortex critical for emotional ________ Hypothalamus governs ________ expression of emotion

Cortex critical for emotional *experience* Hypothalamus governs *behavioral* expression of emotion

How does the dopamine system change with chronic drug use?

D2 receptors are lower in individuals with addictions

DREADD Receptors

DREADDs give us remote control over neuronal activity

Episodic Memory

Declarative memory of an event (ie. your first day of school) -Storage in Cortex

Semantic Memory

Declarative memory of facts (ie. capital of France) -Storage in Cortex

Benzodiazepines

Drugs that lower anxiety and reduce stress and are used to ease withdrawal symptoms

How do patients with schizophrenia perform in card sorting tests?

During these tasks, patients with SCZ tend to perform worse; but even when you match on performance, they show reduced frontal activity, specifically in the dlPFC.

Evidence Implicating Medial Temporal Lobes in consolidation and storage of declarative memory

Electrical stimulation of temporal lobes Recordings from temporal lobes Temporal lobe amnesia in humans (HM) Temporal lobe amnesia in animals (delayed non-match to sample)

Which treatments can provide relief from depressive symptoms immediately?

Electroconvulsive therapy (ECT) and Deep Brain Stimulation

Endocannabinoids

Endogenous substances that act like the active ingredient in marijuana to stimulate hunger

Prandial state—anabolism

Energy storage as glycogen and triglycerides

Describe the brain differences observed in schizophrenia

Enlarged ventricles -Reduced gray matter volume (cell bodies) & enlarged ventricles -Areas of reduced volume: particularly in the cortex, amygdala, and hippocampus. -These differences are observed before the onset of symptoms, so it's not fully a consequence. -However, GMV does decline during the course of the disease. -Additional factors: •Decreased cell body size •Decreased dendrites •Decreased axon terminals •Reduced cortical thickness and abnormal lamination •Disorganized cell orientation in the hippocampus •White matter has less myelination and decreased organization

Trisynaptic circuit of the hippocampus

Entohinal cortex -> (preforant path) DG -> (mossy fibers) CA3 -> (Schaffer collaterals) CA1 -By recording from these CA1 neurons, scientist have been able to study properties of the circuitry/ synapses. -Both increases and decreases in synaptic weights can shift neuronal selectivity and store information

What are some consequences of chronic stress?

Excitotoxicity (chronic calcium entry); cell death (degeneration) in hippocampus, ulcers, enlarged adrenal glands, heightened anxiety, memory disruption, PTSD heightened anxiety

True or False: Aggression is an emotion

False

True or False: Forgetting is the enemy of memory.

False. -One of the most counterintuitive findings from memory science is that the process of forgetting actually helps learning. When it is hard to retrieve information from long-term memory, the likelihood of recalling this piece of information in the future will be increased. This is known as desirable difficulty - the more effort put into retrieval, the greater the learning -Strengthens synapses

Gastric Phase

Feeling full Gastric distension signals brain via vagus nerve. -Works synergistically with CCK released in intestines in response to certain foods -Insulin also released by β cells of the pancreas— important in anabolism

Dopamine hypothesis

First discovered through amphetamines, causes the release of dopamine. When you start using it often, can experience psychosis very similar to SCZ. -Suggests that psychotic episodes are triggered by the activation of dopamine receptors

Substrate Phase

Food Absorption -Insulin release is maximal when the food is finally absorbed in the intestines -Primary stimulus for insulin release is increased blood glucose levels -Satiety STOP eating

Limited Amnesia

Forgetting a specific experience as a result of trauma

VMHdm-dorsal medial and/or VMHc-central stimulation leads to...

Freezing and Flight

Draw a diagram to compare the pattern of neural communication between neurons of the secretory hypothalamus, network of neurons of the ANS, and diffuse modulatory systems

Hormones have more widespread effects in the brain and body, can target many sites in the body, and have often longer lasting effects compared to traditional neurotransmitters.

Response to decreased leptin levels

Humoral - NPY and AgRP inhibit secretion of TSH and ACTH Visceromotor- Activate parasympathetic division of ANS Somatic - Stimulate LH & feeding behavior

Name three ways that the hypothalamus responds to sensory input to maintain homeostasis

Humoral, visceromotor, & somatic motor response

Cephalic Phase

Hunger (anticipation of food triggered by sight, odor, taste or just thinking about food!) -Ghrelin released when stomach is empty -Activates NPY/AgRP-containing neurons in arcuate nucleus -Removal of ghrelin-secreting cells of stomach thought to cause loss of appetite

Human Narcolepsy results from the selective death of _________-containing neurons in most cases.

Hypocretin -a small peptide neurotransmitter expressed mainly by neurons whose cell bodies are in the lateral hypothalamus. The axons of hypocretin (orexin)-secreting neurons project widely in the brain, and they strongly excite cells of the cholinergic, noradrenergic, serotonergic, dopaminergic, and histaminergic modulatory systems. -promotes wakefulness, inhibits REM sleep, facilitates neurons that enhance certain kinds of motor behavior, and is involved in the regulation of neuroendocrine and autonomic systems

Somatic motor response

Hypothalamic neurons (particularly within the lateral hypothalamus) respond to sensory signals by inciting an appropriate somatic motor behavioral response. --> MOTIVATED BEHAVIORS

Humoral response

Hypothalamic neurons respond to sensory signals by stimulating or inhibiting the release of pituitary hormones into the bloodstream.

How do animals respond to stimulation of the hypothalamus?

Hypothalamus is master regulator! So stimulation → cause animal to sniff, pant, eat, or express behaviors characteristic of fear / anger (similar to sham rage)

Circadian Rhythms

Internally generated patterns of body functions, including hormonal signals, sleep, blood pressure, and temperature regulation, which have approximately a 24-hour cycle and occur even in the absence of normal cues about whether it is day or night -based on light/dark cycle

Control of Feeding by LH Peptides

LH neurons stimulating feeding behavior contain: -Melanin-concentrating hormone (MCH) --Widespread connections in the brain --Prolongs consumption Orexin -Also with widespread cortical connections --Promotes meal initiation

Anorexia is from _______ hypothalamic syndrome

Lateral

Tongue protrusion for a rat signifies...

Liking

Electroconvulsive therapy (ECT)

Localized electrical stimulation -Unknown mechanism in relieving depression -Affects temporal lobe -Advantage: quick relief of depression, mania -Adverse effect: loss of prior memories, impaired storage of new information

______ cells in the LH region prolong consumption

MCH

Homeostasis

Maintenance of body's internal environment within a narrow physiological range -Also involves temperature regulation: sweat, shunt blood to surface tissues where heat can radiate away, move to shade, seek water, etc

Endocannabinoid system

Major regulator of appetite and feeding

Procedural Memory

Memory for skills, including perceptual, motor, and cognitive skills required to complete tasks

Modification in the input-output relationship between neurons are the physical changes that lead to __________

Memory formation -Kandel showed that simple forms of learning are accompanied by changes in the strength of synapses

Retrograde Amnesia

Memory loss for things prior to brain trauma

Name the biological theories of affective disorders

Monoamine hypothesis, Diathesis-Stress Hypothesis, Anterior Cingulate Cortex Dysfunction

What is the hallmark of anxiety disorders?

Occurrence of inappropriate stress response either when a stressor is not present or not immediately threatening

Central Nervous System

Only found in CNS and consists of related cell groups that differ with respect to the neurotransmitter they use. Cell groups extend their spatial reach with highly divergent axonal projections and prolong their actions by using metabotropic postsynaptic receptors. -Known as the diffuse modulatory system of the brain. It is believed to regulate levels of arousal and mood.

How do we stimulate the hypothalamus?

Optogenetics -Use a viral vector to deliver the channelrhodopsin (light activated channel) into cells in the hypothalamus. You then use a fiber optic cable to shine a blue light and turn those neurons on (channel opens, Na+ flows in, depolarization to threshold, you trigger an AP). You observe the behavior of the animal and then after the experiment you can go in and see specifically which neurons were infected with the virus and activated by the light

_______ cells in the LH region promote meal initiation

Orexin

Postganglionic Neurotransmitters

Parasympathetic: release Ach -Local effect Sympathetic: most release NE -Far-reaching effects Parasympathomimetic: mimic or promote muscarinic actions of ACh or inhibit actions of NE Sympathomimetic: mimic or promote NE actions or inhibit muscarinic actions of ACh

Redundancy

Physiological systems show redundancy—they are monitored by more than one mechanism

Permanent vs transient amygdala lesions

Plasticity changes after early permanent amygdala damage result in more extensive behavioral changes compared with the transient chemogenetic inhibition of the amygdala

Environmental risk for schizophrenia

Prenatal risk •Rhesus incompatibility •Influenza •Nutritional deficiency •Birth complications •Extreme maternal stress Psychosocial / cultural risk •Expressed emotion in family members -Criticism, hostility, emotional over-involvement •Urban living •Immigration

Dissociated Amnesia

Present with no other cognitive deficits

Cholinergic neurons: Some enhance ______ events, others active during waking.

REM

Effects of Hippocampal Lesions in Rats

Radial arm maze -Normal rats are efficient go down each arm of the maze for food only once! -Lesioned rats never learn this efficiency! (go down the same arms more than once - no food after the first trip). -Rats do seem to learn that they go down the arms in search of food (procedural memory) but can't remember which arms they already visited ---Can learn to avoid no food arms, but will still go down the arms with food more than once

Sham Rage

Rage but in a situation that normally would not cause anger

Spatial Memory and Morris Water Maze

Rats are placed in a maze of milky water with a small platform and swim until they find the location of the platform. -Rats usually learn quickly where the platform is located -Rats with bilateral hippocampal damage never seem to remember the location of the platform

Obsessions

Recurrent, intrusive thoughts, images, ideas, or impulses

Lesions of LH (lateral hypothalamus)

Reduce food seeking and result in anorexia, severe loss of weight

Hypofrontality

Reduced activity in the prefrontal cortex during executive function tasks

Why does marijuana make us eat more?

Reducing granule cell (inhibitory neurons) activation by glutamate in the olfactory bulb has the net effect of enhancing the sense of smell Much of the appetite stimulation comes from enhancing the sense of smell

Leptin

Released by adipocytes (fat cells), regulates body mass by acting directly on neurons of the hypothalamus that decrease appetite and increase energy expenditure.

Vasopressin (aka ADH)

Released by magnocellular neurosecratory cells of the posterior pituitary & synthesized by hypothalamus - regulates blood volume and salt concentration -Lead to water retention and decreased urine output **triggered by renin from kidney

Amphetamine stimulates...

Releases of all the monoamines (NE, Serotonin and DA) through reversal of their transporters! NOTE this is NOT release via vesicle fusion but transmitter being transported out of the neuron through the transporters (i.e. transport in the wrong direction!)

Compulsions

Repetitive behaviors to reduce anxiety

Reconsolidating

Return of memory trace to stable long-term storage after recall -Every time we retrieve a memory we alter it, our emotions and experiences at the time of retrieval influence our memory of the event --Lost in the mall story --Rats can have their memory of a box changed if they get shocked while the memory is reactivated

Vasopressin & Oxytocin Receptors are expressed in the _____________ pathway

Reward -The Nucleus Accumbens (NAc) is part of the reward pathway

Prospagnosia

Selective amnesia for familiar faces which results from damage to the IT cortex

Describe the neural circuit that supports learned fear

Sensory cortex, hippocampus, thalamus, amygdala

Information Flow through the MTl

Sensory information -> cortical association areas -> parahippocampal and rhinal cortical areas -> hippocampus -> (formix) -> thalamus, hypothalamus

Amnesia

Serious loss of memory and/or ability to learn -Causes: concussion, chronic alcoholism, encephalitis, brain tumor, stroke

For chronically stressed individuals, dendrites are ___________

Shorter!

Is LTP easier to induce in highly active (mature) or silent synapses?

Silent Synapse (an excitatory glutamatergic synapse whose post synaptic membrane contains NMDA receptors but NO AMPA receptors)

Prolactin

Stimulates milk production -Targets mammary glands

ACTH (adrenocorticotropic hormone)

Stimulates secretion of cortisol by adrenal cortex (which mobilizes energy stores and inhibits the immune system)

TSH (thyroid stimulating hormone)

Stimulates secretion of thyroxin (which increases metabolic rate) -Targets the thyroid

Lesions of VMH (ventromedial hypothalamus)

Stimulation of feeding and over intake and obesity

GH (growth hormone)

Stimulation of protein synthesis -Targets all cells

Describe the HPA (hypothalamic-pituitary adrenal) axis in terms of structure and function

Stress --> CRH (hypothalamus) --> ACTH (anterior pituitary) --> Cortisol (adrenal gland) -Somatic Motor Response -Visceromotor = ANS activation -Humoral response = HPA activation

Stress Pathway

Stress --> cortisol from adrenal cortex -Chronic Cortisol --> negative side effects

Cortisol

Stress Steroid -Mobilizes energy & suppresses immune system!

Diathesis Stress Model and Schizophrenia

Strong genetic basis for SCZ; identical twins share all their genes, but there's only a 50% likelihood of developing it if your ID twin has it. Probability decreases the fewer genes you share. -Combination of having a genetic vulnerability and experiencing an environmental stressor; one or the other will not result in a diagnosis, some combination of the two

Synchronous activity of brain waves =....

Synchronous activity = larger amplitude waves

Memory Consolidation

The gradual, physical process of converting new long-term memories to stable, enduring memory codes

Response to high leptin levels

The humoral response: increased secretion of TSH (thyroid-stimulating hormone) and ACTH (adrenocorticotropic hormone). Act on the thyroid and adrenal glands and have the effect of raising the metabolic rate of cells throughout the body. (Anterior pituitary pariventricular nucleus) The viscero-motor response: increases the tone of the sympathetic division of the ANS, which also raises metabolic rate, in part by raising body temperature. (Intermediolateral gray matter of spinal cord) The somatic motor response: decreases feeding behavior. The αMSH/CART neurons of the arcuate nucleus project their axons directly to the regions of the nervous system that orchestrate this coordinated response (lateral hypothalamus)

Which part of the brain is related to leptin signaling

The hypothalamus -The arcuate nucleus and hormones are also involved

Glutamate hypothesis

The idea that schizophrenia may be caused, in part, by understimulation of glutamate receptors -Discovered through studies fo PCP use •Clogs the pore rather than blocks the binding of glutamate •Relies on open & active channels •GABAergic neurons in cerebral cortex •Patients have fewer interneurons in cortex -Can result in sensory processing deficits and distorted thinking.

How do orexigenic peptides affect appitite

The increase it

Cue-indicated Drug Use

The increased likelihood of using a drug because factors are present that were also present when the drug was last used

Metaplasticity

The modulation of long term potentiation (LTP) and/or long-term depression (LTD) induction by prior synaptic activity -The plasticity of plasticity

Memory trace

The physical representation or location of a memory; also known as an engram

Role of the posterior hypothalamus

The posterior hypothalamus may be particularly important for the expression of anger and aggression and that normally it is inhibited by the telencephalon

Set zone

The range of tolerance in a system

Memory

The retention of learned information

Sympathetic vs Parasympathetic nervous system

The sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. The parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

Synaptic Homeostasis

Unchecked synaptic plasticity could lead to unstable neuronal responses -LTP cannot go on forever, computer models suggest all synapses would be potentiated eventually and memory trace would be lost! -Homeostatic mechanisms needed to provide stability and keep synaptic weights within useful dynamic range

Overeating is from _______ hypothalamic syndrome

Ventromedial

Declarative memories reside in the _________ cortex

Visual (IT) -continuous presentation of a visual stimuli allows neuronal patterns in the IT cortex to be generated -each generated pattern then allows us to discriminate between familiar and unfamiliar stimuli

Noradrenergic and serotoninergic neurons: fire during and enhance ______ state

Waking

Electrical self-stimulation is an example of....

Wanting

Deep Brain Stimulation

We use this treatment When severe depression fails to respond to other treatments (because it requires invasive brain surgery!) -Electrode implanted deep in the brain Region of anterior cingulate cortex (Brodmann's area 25) -Electrical stimulation --> decrease activity in brain circuits that are chronically overactive -Immediate relief from depression -Preliminary findings, brain surgery a treatment of last resort

You are testing memory in Drosophila. You overexpress CREB-2. What is the likely consequence?

You've repressed gene expression and blocked the mutant flies memory consolidation

Predatory aggression

•Attack •Against different species for food •Few vocalizations, attack head or neck •No activity in sympathetic division of ANS.

Describe the effects of amygdala stimulation and lesions of the amygdala

•Bilateral amygdalectomy reduces fear and aggression in all animals tested. •Anger, sadness, and disgust may also be affected. •S.M. case study: inability to recognize fear in facial expressions •Electrical stimulation of amygdala -> increased vigilance or attention—anxiety and fear in humans; violent aggression in cats •fMRI imaging: Fearful faces evoke greater amygdala activity than happy or neutral faces.

Summary of effects of amygdala lesions, stimulation, and inhibition

•Bilateral amygdalectomy reduces fear and aggression in all animals tested. •Anger, sadness, and disgust may also be affected. •S.M. case study: inability to recognize fear in facial expressions due to abnormal eye movements •Electrical stimulation of amygdala -> increased vigilance or attention—anxiety and fear in humans, aggression in cats •fMRI imaging: Fearful faces evoke greater amygdala activity than happy or neutral faces. •Temporary inhibition of amygdala results in decreased fear and anxiety but hostility and vocalizations are not changed like they are when you lesion the animals

Hypothalamic Control of the Anterior Pituitary

•Controlled by parvocellular neurosecretory cells •Secrete hypophysiotropic hormones •Hypothalamo-pituitary portal circulation •Pituitary cells secrete or stop secreting hormones. -Parvo cells communicate with targets via bloodstream bc axons do not extend all the way down

Summary of Anger and Agression

•Controversy remains about extent to which emotions cause body changes or bodily changes cause emotions. •Brain imaging shows emotions are associated with widespread brain activation. •Some brain structures activated in multiple emotional states, others more specific to particular emotions. •Emotional experiences are the result of complex interactions among sensory stimuli, brain circuitry, past experiences, and activity of neurotransmitter systems

Describe the symptoms of depression

•Decreased interest or pleasure in all activities •Loss of appetite (or increased appetite) •Insomnia (or hypersomnia) •Fatigue •Feelings of worthlessness and guilt •A diminished ability to concentrate •Recurrent thoughts of death

Describe one piece of experimental evidence supporting the role of serotonin in modulating aggressive behavior for monkeys

•Dominance hierarchy can be manipulated by drugs that increase and decrease 5HT •More aggression associated with less 5HT activity

Describe one piece of experimental evidence supporting the role of serotonin in modulating aggressive behavior for rodents

•Drug PCPA blocks serotonin synthesis—aggression •Agonists of 5-HT1B receptors ¯ aggression (antagonists opposite effect) •5-HT1B KO mice show increased aggressive behavior •Animals in isolation ¯Serotonin turnover—aggression in male rodents -No change in serotonin in females - no aggression after isolation

Stimulation of the medial hypothalamus elicits...

•Elicit affective aggression (threat attack) by stimulating medial hypothalamus •High levels of ANS sympathetic activation

dimensional theories of emotion

•Emotions can be broken down into smaller fundamental elements combined in different ways and amounts •Valence (pleasant - unpleasant); Arousal (weak emotion - strong emotion) •Sub-patterns of brain activation associated with degree of valence

Affective aggression

•For show •Used for show, not kill for food •High levels of sympathetic activity •Makes vocalizations, threatening posture

Describe one piece of experimental evidence supporting the role of serotonin in modulating aggressive behavior for humans

•In humans also, reports of negative correlation between serotonin activity and aggression. -Caution correlation is not causality and it is likely more complicated!

Effects of Sleep Deprivation

•Increased irritability •Difficulty in concentrating •Episodes of disorientationSleep rebound (increased sleep time the next time you sleep)

Basic Theory of Emotions

•Most highly activated region uniquely represents an emotion (i.e. PFC for sadness and Amygdala for fear) •Pattern of activation could be the basis of the emotion (i.e. each active brain region a piece of the puzzle) •Basic Emotions: anger, disgust, fear, happiness, sadness, and surprise

Explain how human sleep patterns change with age

•Overall reduction in sleep & earlier wake up times •Reductions in the proportion of REM sleep (20%), especially relative to early stages in life (childhood & infancy 50%) •By age 40 to 50 we can lose as much as 50% of our deep, non-rem sleep! And by age 70 it can be as much as 90%. Not good and linked to diseases like Alzheimer's Disease and deficits in learning and memory •A lot of sleep disruptions (pain, bathroom trips, etc.) are seen in old age. You don't go to sleep and stay asleep anymore. •PROTECTING YOUR SLEEP IS PROTECTING THE HEALTH OF YOUR MIND AND BODY! (remember from the podcast shorter sleep = shorter life)

Stress response and the anterior pituitary

•Periventricular hypothalamus secretes CRH into portal circulation. •ACTH released into circulation •ACTH stimulates cortisol release from adrenal cortex.

Stimulation of the lateral hypothalamus elicits...

•Predatory aggression is elicited by stimulating lateral hypothalamus •NOT associated with high levels of ANS sympathetic activation

Kluver-Bucy syndrome

•Produced by temporal lobectomy in rhesus monkeys •Decreased fear and aggression •Decreased vocalizations and facial expressions of fear •Temporal lobe lesions in humans—particularly lesions in amygdala •Exhibit symptoms of Klüver-Bucy syndrome •Flattened emotions

Infant sleep is characterized by..

•Shorter sleep cycles •More REM sleep—50%, which may provide essential stimulation to the developing nervous system

Reasons we sleep

•Sleep as brain's way of disconnecting cortex from sensory input •By synchronizing oscillations from different regions, brain may bind together a single perceptual construction. •Sleep deprivation is devastating to proper functioning. •Purpose of sleep still unclear •Memory consolidation •The brain's lymphatic system is particularly active when we sleep and helps clear debris including beta amyloid (Mathew Walker) •For our brain, prevents cognitive impairment that comes with sleep deprivation

Genetic risk for schizophrenia

•Strong genetic basis for developing schizophrenia •Many genes related to synaptic transmission