Chapter 3: Neuroscience and Behavior
Basal ganglia
Set of subcortical structures that directs intentional movements
Brain networks
Sets of brain regions closely connected to one another
Split-brain procedure
Severing of corpus callosum in those that have severe seizures (begin in one side and cross corpus callosum to opposite hemisphere and start feedback loop)
Chimeric face
Shows result of split brain; assembled from half-face components of full faces shown in figure
In which animal species did the first neurons appear?
Simple invertebrates like jellyfish
Spinal reflexes
Simple pathways in the nervous system that rapidly generate muscle contractions; no need for the brain in these, just sensory inputs and motor neurons Ex: Touch hot stove -> Sensory neurons -> Interneurons (in spinal cord) relay info to motor neurons -> retract hand
What is an example of a simple animal with sensory neurons and motor neurons?
Single-celled protozoa -> molecules in membrane sensitive to food and water -> movement of threads called cilia
Ions
Small electrically charged molecules
Which is the only sense that the thalamus does not receive input from?
Smell; has direct connections to cerebral cortex
If a neuron was compared to a prison, the ______ could be compared to the prisoners when the neuron is at the resting potential
Sodium ions
Unlike the autonomic nervous system, humans have voluntary control over the ________ nervous system
Somatic
What are the two major divisions of the peripheral nervous system?
Somatic and autonomic
What do glial cells do?
Some digest parts of dead neurons; others provide physical and nutritional support for neurons, others form myelin
Epigenetic writers
Special enzymes whose role is to add methyl groups to DNA
Anya is having a baby and it is three and a half weeks since conception. At this stage, _______ will have begun to form from the neural tube
Spinal cord
The ______ allows people to perform functions such as breathing, walking, and moving muscles
Spinal cord
The neural tube grows to form the basis of the
Spinal cord
_________ are simple pathways in the nervous system that rapidly generate muscle contractions
Spinal reflexes
Motor cortex
Strip of brain tissue; like the somatosensory cortex, different parts of motor cortex correspond to diff body parts; voluntary movements and sends messages to basal ganglia, cerebellum, and spinal cord
Pons
Structure that relays info from the cerebellum to the rest of the brain; relay station/bridge between cerebellum and other structures in the brain
What are the indentations or fissures called?
Sulci
Glial cells
Support cells found in the nervous system (10-50x number of neurons)
What are the two subdivisions of the autonomic nervous system?
Sympathetic and parasympathetic nervous system
Neurotransmitters are chemicals that transmit info across the _______ to dendrites on the receiving neuron
Synapse
How is the thalamus like a compute?
Takes in multiple inputs and relays them to a variety of locations; active filter of sensory info and gives more weight to some and not to other
Damage to the _________ could leave a person unable to navigate his or her way through a room
Tectum
The ______ is an area of the midbrain that orients an organism in the environment
Tectum
What are the two structures in the midbrain?
Tectum and tegmentum
Heritability is a population concept. That means it
Tells nothing about the individual
Ceclia recently was in a car accident and afterward developed an inability to produce language. She most likely suffered damage to her _________ lobe
Temporal
The knob-like structures that branch out from an axon and release neurotransmitters are referred to as ___________
Terminal buttons
In some psychology experiments, participants are presented with conflicting visual and audio info. In these cases, an area of the brain called the ___________ gives more or less weight to these signals, determining which info overrides the other
Thalamus
What are two ways to divy up the brain?
"Bottom to top" areas where simpler functions are performed at lower levels and more complex functions are at higher levels "Side-by-side" -> Though analogous; one half specializes in some tasks than the other half doesn't
Demyelinating diseases
(Example is multiple sclerosis); deterioration of myelin sheath and slowing of transmission of info from one neuron to another
What is the measure of a neuron's resting potential and when was it first measured?
-70 mV; 1930s
Reticular formation
Begins inside medullar and extends upwards; small cluster of neurons which regulate sleep, wakefulness, and levels of arousal
What is the primary function of the corpus callosum?
Communication between the hemispheres
What tells the dendrites which of the neurotransmitters flooding into synapse to receive?
1. Neurons tend to form pathways in the brain characterized by specific types of neurotransmitters 2. Lock and key system (neurotransmitters and receptor sites) -> only some neurotransmitters bind to specific receptor sites on dendrite
What are three ways scientists study the brain?
1. Study people w brain damage 2. Brain's electrical activity 3. Using brain imaging
What happens during the 4th through 7th weeks after fertilization?
4th: three levels of brain are visible 5th: forebrain and hindbrain differentiate into subdivisions 7th: Forebrain expands to form hemispheres
How many chemicals play a role in transmitting info through your brain?
60
What is the cell body surrounded by?
A porous cell membrane that allows some molecules to flow into and out of the cell
Plasticity of brain
Ability to be molded; functions that were assigned to certain areas of the brain may be capable of being reassigned to other areas of the brain to accommodate changing input from the environment ("competition" for representation of sensory inputs in each cortical area)
What happens to people with damage to the hippocampus?
Able to acquire new info and keep in awareness for a second, but, once distracted, forget info and experience that produced it Ex: Can remember how to drive and talk, but can't recall where they have recently driven
What are the four important points to bear about heritability?
Abstract concept: Tells nothing about specific genes contributing t a trait Population concept: Tells nothing about individual Depends on environment Not fate: tells nothing about degree to which interventions can change behavioral trait
Mirror neurons
Active when animal performs a behavior, such as reaching for or manipulating an object, and also activated when another animal observes that animal performing the same behavior Related to recognizing goal someone has in carrying out an action rather than the particular movements of that action
How do split-brain patients function normally in the world even though their hemispheres don't communicate?
Adapt by moving eyes to get info to both hemispheres
DNA methylation
Add methyl group to DNA = switches off methylated gene (there, but contents are not expressed)
Histone modification
Adding chemical modification to proteins called histones that are involved in packaging DNA == can either switch genes on or off (influence gene expression without altering underlying DNA sequence)
Methamphetamine
Affects pathways for dopamine, serotonin and norepinehrine at neuron's synapses; difficult to interpret -> combination of agonist and antagonist effects alters functions of neurotransmitters that help us perceive and interpret visual images == strange hallucinations
Patients suffering from Parkinson's disease have trouble with motor skills because they have problems with their dopamine levels. L-Dopa is used to treat the symptoms of the disease because it is a(n) ________ for the neurotransmitter. This means it increase the activity of dopamine
Agonist
Deterioration of acetylcholine-producing neurons has been associated with:
Alzheimer's disease
What disease is associated with the deterioration of ACh-producing neurons?
Alzheimer's disease (memory impairments)
What two drugs prevent the reuptake of norepinephrine and dopamine as well as stimulate increased release?
Amphetamine and cocaine, two agonists
Phantom limb syndrome refers to a phenomenon when
Amputees continue to experience sensations in a missing body part
The _______ is an area of the brain that plays a role in the emotional processes and the formation of emotional memories
Amygdala
What is the imbalance following the refractory period reversed by?
An active chemical pump in cell membrane that moves Na+ outside axon and moves K+ inside axon
Action potential
An electric signal that is conducted along the length of a neuron's axon to a synapse
Myelin sheath
An insulating layer of fatty material, composed of glial cells
Nervous system
An interacting network of neurons that conveys electrochemical information throughout the body
Propranalol
Antagonist; beta blocker -> blocks receptor site for norepinephrine in heart -> norepinephrine can't bind to these receptors so heart rate slows down (helpful for those people with disorders where the heart beats too fast or irregularly)
How many nerve cells are there in your brain?
Approximately 100 billion
Subcortical structures
Areas of forebrain housed under cerebral cortex near the center of the brain
How does the pituitary gland work during breastfeeding?
Baby suckles mother's breast -> sensory neurons in breast send signals to hypothalamus -> signals pituitary gland to release hormone called oxytocin -> stimulates release of milk from reservoirs in the breast
Occipital lobe
Back of cerebral cortex; process visual info Sensory receptors in eyes send info to thalamus -> info to primary areas of occipital lobe -> simple features are extracted -> processed into more complex map of stimulus
After damage to the spinal cord, the amount of function that is lost is:
Based on the localization of the damage
Why do SSRIs help people suffering from clinical depression?
Because they have reduced levels of serotonin (elevates mood), the block of reuptake allows more of the neurotransmitter to remain in the synapse and produces greater activation of serotonin receptors
Frontal lobe
Behind forehead; specialized areas for movement, abstract thinking, planning, memory, judgment Contains motor cortex (coordinates movements of muscle groups throughout body), other areas that coordinate thought processes that help manipulate info and retrieve memories
Pituitary gland
Below hypothalamus; "Master gland" of body's hormone-producing system which releases hormones that direct functions of many other glands in the body
Homunculus
Body parts are rendered according to how much of somatosensory cortex is devoted to it
Central nervous system (CNS)
Brain and spinal cord; receives sensory info from external world, processes and coordinates and then sends commands to skeletal and muscular systems for action
Identifying the brain areas that are involved in specific types of motor, cognitive, or emotional processing is best achieved through
Brain imaging
Somatosensory cortex
Brain tissue running from top of brain down to side; represents skin areas on contralateral surface of the body -> each part maps onto particular part of the body (larger part of somatosensory cortex devoted to more sensitive part of body) Ex: Homunculus
What is the spinal cord's function?
Branches from brain; nerves that process sensory info and relay commands to the body connect to spinal cord
What are nodes of Ranvier?
Breakpoints in the myelin sheath; the myelin doesn't cover entire axon, but rather clumps around axon with break points
Axons
CARRIES information to other neurons, muscles, or glands (the long thing covered by myelin sheath connecting cell bodies to its dendrites)
Lighting a match can be compared to an action potential because both events:
Can be described as all-or-none events
Motor neurons
Carry signals from spinal cord to muscles to produce movement; often have long axons that stretch to muscles at extremities
Neurons
Cells in nervous system that communicate with one another to perform information-processing tasks
Two main divisions of the nervous system:
Central nervous system and peripheral nervous system
A person who has serious problems with balance may have suffered damage to their ___________
Cerebellum
During the course of embryonic brain growth, the ______ undergoes the greatest development.
Cerebral cortex
The ____________ is the outermost layer of the brain, visible to the naked eye, and divided into two hemispheres
Cerebral cortex
Threshold
Certain level ONLY at which action potential occurs
Epigenetic marks
Chemical modifications to DNA that can turn genes on or off
Neurons are not connected physically but communicate _____ with each other at the ________
Chemically; synpase
Endorphins
Chemicals that act within pain pathways and emotion centers of brain; dulls experience of pain and elevates moods
Neurotransmitters
Chemicals that transmit information across synapse to a receiving neuron's dendrites
What does the thalamus do during sleep?
Closes pathways of incoming sensations during sleep, providing function in not allowing info to pass to rest of brain
How are the cerebral hemispheres connected?
Commissures; bundles of axons that make possible communication between parallel areas of the cortex in each half
Association areas
Composed of neurons that help provide sense and meaning to info registered in the cortex
What are the two ways neurons communicate info within and between themselves?
Conduction and transmission
Interneurons
Connect sensory neurons, motor neurons, or other interneurons
Peripheral nervous system (PNS)
Connects central nervous system to body's organs and muscles
Nucleus
Contained within the cell body; houses chromosomes that contain your DNA
The two hemispheres of the cerebral cortex have ________ control of the body, such that each controls the side opposite of its location
Contralateral
What is the largest of the commissures called and what does it do?
Corpus callosum; connects large areas of the cerebral cortex on each side of the brain and supports communication of info across hemispheres
Jack is a split-brain patient and he is presented with a picture of a phone on the left side of a computer screen and a picture of a cake on the right side. If he were asked to draw the object he saw on the right side of the screen with his left hand, he:
Could not draw anything
Timmy is a split-brain patient and he is presented with a picture of a phone on the left side of a computer screen and a picture of a cake on the right side. If he were asked to say what object he saw on the left side of the screen, he:
Could not verbalize that he saw anything; Left side controls speech and the right side controls artistic capabilities. As he is asked to speak about something seen on the left side of the screen and because of the contralateralness of the brain, he will be unable to speak because the information from his left visual cortex will go to the right side of the brain.
Hippocampus
Critical for creating new memories and integrating into network of knowledge so they can be stored indefinitely in other parts of the cerebral cortex
What are two widely studied epigenetic marks?
DNA methylation & Histone modification
What are the two types of specialized extensions of the cell membrane that allow them to communicate?
Dendrites and axons
Functional magnetic resonance imaging (fMRI)
Detects difference between oxygenated hemoglobin and deoxygenated hemoglobin when exposed to magnetic pulses; increased concentration of oxygenated hemoglobin means activity is occurring -> detects oxygenated hemoglobin; Can be used to explore relationship of brain regions with one another
Dizygotic twins (fraternal)
Develop from two separate fertilized eggs and share 50% of genes
Electroencephalograph (EEG)
Device used to record electrical activity in the brain; electrodes placed on outside of head; make fundamental discoveries about nature of sleep and wakefulness
Resting potential
Difference in electric charge between the inside and outside of a neuron's cell membrane
How does the electric charge of the action potential move down the axon?
Domino effect -> when action potential generated at beginning, spreads short distance -> generates action potential at nearby location -> etc
________ is the neurotransmitter that regulates MOTOR BEHAVIOR, motivation, pleasure, and emotional arousal
Dopamine
How does L-dopa alleviate symptoms of Parkinson's disease?
Dopamine is created by modification of common molecule called L-dopa. Ingestion of L-dopa will elevate amount in brain and spur surviving neurons to produce more dopamine -- L-dopa acts as an agonist for dopamine
What parts are affected when someone suffers from Parkinson's disease?
Dopamine-producing neurons in tegmentum of midbrain are damaged -> undersupply affects the striatum in basal ganglia
Where does dopamine play a role?
Drug addiction
Antagonists
Drugs that block function of neurotransmitter; blocks action of neurotransmitter (structurally similar to neurotransmitter that is able to bind with the receptor)
Agonists
Drugs that increase action of a neurotransmitter; activates neurotransmitter (structurally similar to neurotransmitter that is able to bind with the receptor)
Why does action potential reach a value above 0?
During resting potential, channels allowing K+ to flow out are open. When charge raised to threshold value, channels briefly shut down and channels that allow flow of positively charged sodium ions (Na+) are opened. As Na+ is more concentrated on the outside, it flows inside and increases positive charge inside axon relative to the outside.
If James has trouble sleeping and wants to have doctors measure his brain activity while he is asleep, the doctors will most likely use a technique abbreviated as _____ to do so.
EEG
What is a device that measures electrical activity in brain during dreams?
EEG
Contralateral control
Each hemisphere controls functions of the opposite side of the body
What did James Olds and Peter Milner find?
Electric current delivered to certain region of rat's hypothalamus was extremely rewarding and when allowed to initiate own stimulation, would often do to point of exhaustion
Within a neuron, information is transmitted as a(n) ________ travels from the dendrites to the cell body and throughout the axon
Electrical signal
Both stages of communication between neurons can be said to use _______ signaling
Electrochemical
Synaptic transmission
Electrochemical action where action potential travels down length of one axon, through the synapse and then on to the next neuron; allows neurons to communicate
What chemical is runner's high attributed to?
Endorphins
Epigenetics
Environmental influences that determine whether or not genes are expressed, or the degree to which they are expressed without altering the basic DNA sequences that constitute the genes themselves AKA genes are like the script of a play; you can read the lines in different ways
Chemical modifications to DNA that can turn genes on or off are called
Epigenetic marks
What was Roger Sperry intrigued by in terms of the corpus callosum?
Everyday behavior of people with severed corpus callosum is same as everyone else -> independence of the functionality of left and right hemispheres
Medulla
Extension of spinal cord into the skull that coordinates heart rate, circulation, and respiration
What emotion is most closely associated with the amygdala?
Fear
The first true central nervous system appeared in
Flatworms
In which species did the first central nervous system appear?
Flatworms; collection of neurons in head including sensory neurons for vision and taste + pair of tracts forming spinal cord
What happens when amphetamine and cocaine prevent reuptake with the increased release that has been stimulated?
Flood in synapses of these neurotransmitters; increased activation of receptors
What are the three divisions when looking from top to bottom?
Forebrain Midbrain Hindbrain
Pyramidal cells
Found in cerebral cortex; triangular cell body and single long dendrite among many other dendrities
How are the hemispheres of the cerebral cortex divided?
Four lobes; from back to front = occipital, parietal, temporal, frontal
A person with damage to the ______ lobe would be likely to display difficulty judging what is right and wrong?
Frontal
Phineas Gage primarily suffered damage to his _________ lobe.
Frontal
The _________ lobe is specialized for movement, abstract thinking, planning, memory, and judgment
Frontal
A person who suffers form seizures because of too much glutamate might be prescribed a drug containing _________, because this type of neurotransmitter inhibits information transmission
GABA
A _______ is the unit of hereditary transmission
Gene
_______ is a major excitatory neurotransmitter in the brain, while _______ is a primary inhibitor
Glutamate; GABA (gamma-ainobutyric acid)
Limbic system
Group of forebrain structures including hypothalamus, hippocampus, and amygdala which are involved in motivation, emotion, learning, and memory; where subcortical structures meet the cerebral cortex
Default network
Group of interconnected regions in frontal, temporal, and parietal lobes that is involved in internally focused cognitive activities
The smooth, raised parts of the cerebral cortex are called __________ and the indentations, or fissures, are called sulci
Gyri
What are the smooth surfaces (raised) of the cerebral cortex called?
Gyri
Positron emission tomography (PET)
Harmless radioactive substance injected into bloodstream -> brain scanned by radiation detectors as person performs tasks and areas of brain that are activated need more blood flow and thus higher radioactivity -> record level of radioactivity
What did Santiago Ramon y Cajal?
He learned about a new technique for staining neurons in the brain and realized they came in different shapes and sizes. Neurons are composed of three basic parts: the cell body, the dendrites, and the axon
Parasympathetic nervous system
Helps body return to normal resting state The parasympathetic nervous system generally mirrors the connections of the sympathetic nervous system
In all vertebrates, the CNS is organized into a ________, so that some levels of the brain perform simpler functions while other levels perform more complex functions
Hierarchy
What are the levels of organization within specific lobes?
Hierarchy from primary areas (register frequencies) -> secondary areas (interpret info like shape and motion) -> Association areas (stitch together threads of info to form meaningful understanding; less specialized that neurons in primary areas -> allows for brain plasticity)
What are high levels of dopamine linked to and what are low levels linked to?
High: Schizophrenia, amphetamine psychosis Low: Parkin's disease; tardive dyskensia
Forebrain
Highest level of the brain; controls complex cognitive, emotional, sensory, and motor functions
Patients with amnesia who cannot form new memories usually have damage to the:
Hippocampus
Chromosomes
How genes are organized; strands of DNA wound together in double-helix configuration
Ontogeny
How something develops within a given individual
Phylogeny
How something develops within a particular species
Studies have shown that rats will press a bar that initiates stimulation of the _______________ to the point of exhaustion. This demonstrates this area is associated with reward and pleasure
Hypothalamus
The _________ regulates body temp, hunger, thirst, and sexual behavior.
Hypothalamus
What is the estimate for heritability for human behavior?
In moderate range between .3 and .6 -> meaning that some variability is due to genetic influences and the rest is due to environmental influecnes
How do drugs affect the nervous system?
Increasing, interfering with, or mimicking the manufacture of neurotransmitters
Structural brain imaging
Info about basic structure of the brain
What kind of neurons is most of the nervous system composed?
Interneurons
What was the major split of CNS in organization during the course of evolution?
Invertebrate (no spinal column) vs vertebrate Vertebrates: CNS in hierarchy with higher levels performing more complex functions; reflexes in spinal cord -> midbrain orients -> forebrain has most complex tasks
Serotonin
Involved in regulation of sleep and wakefulness, eating, and aggressive behavior, mood, impulsivity, aggression, appetite
Norepinephrine
Involved in states of vigilance; heightened awareness of dangers in environment; food intake (stimulates intake of carbohydrates)
What causes the conduction of an electric signal within the neuron?
Ions that flow across the neuron's cell membrane
What does the myelin sheath do?
It facilitates the conduction of the action potential
Synapse
Junction or region between the axon of one neuron and the dendrites or cell body of another
What kind of basic behaviors does the hypothalamus oversee?
Keep body temp, blood sugar, and metabolism at optimal range of human functioning; regulate food intake; trigger of hormones when you think about sex; electric stimulation at certain parts can produce hissing and biting whereas at other parts it can produce intense pleasure
Terminal buttons
Knoblike structures that branch out from an axon
Cerebellum
Large structure of the hindbrain that controls fine motor skills
Cell body (Soma)
Largest component of the neuron that coordinates the information-processing tasks (protein synthesis, energy production, and metabolism) and keeps the cell alive
Anytime Tomas remembers the date he had the other night, he feels very excited. He can remember this date and feel this way because of a group of forebrain structures called the _______________
Limbic system
Which body part has more of the somatosensory cortex devoted to them?
Lips
Amygdala
Located at tip of each horn of the hippocampus, plays a central role in many emotional processes, particularly the formation of emotional memories; attaches significance (fear, punishment, reward) to previously neutral event
Parietal lobe
Located in front of the occipital lobe; carries out functions including processing info about touch; contains somatosensory cortex and motor cortex
Where are the basal ganglia located and what do they do?
Located near thalamus and hypothalamus; receive input from cerebral cortex and sends outputs to motor centers in brain stem
Temporal lobe
Located on lower side of each hemisphere; responsible for hearing and language Contains primary auditory cortex -> secondary areas then process info into meaningful units such as speech and words Also houses visual association areas that interpret meaning of visual stimuli
Hypothalamus
Located under thalamus; regulates body temperature, hunger, thirst, and sexual behavior
What happens to the body parts below the level of a spinal cord injury?
Lose sensations of touch and pain in body parts below the level of injury as well as a loss of motor control of the msucles
What is Parkinson's disease caused by?
Loss of neurons that use the neurotransmitter dopamine
What are the different evolutionary advances of the forebrain in vertebrates?
Lower vertebrates like amphibians have a forebrain consisting of small clusters of neurons at end of neural tube Higher vertebrates -> much larger forebrain Reptiles and birds -> No cerebral cortex Mammals -> Highly developed cerebral cortex
Diffusion tensor imaging (DTI)
MRI used to visualize white matter pathways (fiber bundles connecting both nearby and distant brain regions to one another); measures rate and direction of diffusion or movement of water along white matter pathways
Magnetic resonance imaging (MRI)
Mag field to line up nuclei of specific molecules in brain tissue -> pulses of radio waves causing nuclei to rotate out of alignment and then, when the pulse ends, nuclei snap back in line and give off energy
Glutamate
Major excitatory neurotransmitter in brain; enhances transmission of info between neurons
Gene
Major unit of hereditary transmission
Transcranial magnetic stimulation
Manipulation of state of brain: Delivers magnetic pulse that passes through skull and deactivates neurons int eh cerebral cortex for a short period; measures temporary changes in way person moves, sees, etc
Heritability
Measure of variability of behavioral traits among individuals that can be accounted for by genetic factors; calculated as proportion and numerical value ranges from 0 to 1.00 (0 being that genes do not contribute to individual differences and 1.00 mean genes are the only reason)
Damage to the ________ can be deadly because this structure controls heart rate, respiration, and circulation
Medulla
What happens when action potential reaches its maximum?
Membrane channels return to original start and K+ flows until axon returns to resting potential; refractory period
Presynaptic neuron is to postsynaptic neuron as
Message-sending neuron is to message-receiving neuron
_______ acts both as an agonist and as an antagonist to alter neurotransmitters that affect perception and interpretation of visual images
Methamphetamine
Dynus watches Amber reach for a slice of pizza. In response to her behavior, Dynus experiences an activation of his ________ neurons
Mirror
When does plasticity occur?
Missing digits or limbs (phantom limb syndrome) Extraordinary amount of stimulation of one finger -> finger "takes over" representation of part of cortex that usually represents other fingers (Ex: concert pianists have highly developed cortical areas for finger control)
What is the function of the hindbrain?
Most basic functions of life: Respiration, alertness, motor skills
Monozygotic twins (identical)
Most genetically related people; develop from splitting single fertilized egg and share 100% of genes
The neurotransmitter dopamine is involved in
Motivation and pleasure
Tegmentum
Movement and arousal; also helps orient organism towards sensory stimuli
What is Parkinson's disease?
Movement disorder characterized by tremors and difficulty initiating movement
Conduction
Movement of electric signal within neurons, from dendrites to cell body, then throughout the axon
Transmission
Movement of electric signals from one neuron to another over synapse
The _________ is made up of glial cells and helps to insulate the axon
Myelin sheath
Do increases in electric shock above threshold increase the strength of the action potential?
NO. The action potential is all or none.
The _________ system is an interacting network of neurons that conveys electrochemical info throughout the body
Nervous
What is the first major bodily system to take form in an embryo and when?
Nervous system; 3rd week after fertilization (ridge forms on side of sphere -> builds edges to become groove -> becomes deep groove -> ridges fold together and form neural tube)
What explains the apparent beneficial effects of cardiovascular exercise on aspects of brain function and cognitive performance?
Neuron plasticity
Where is acetylcholine found?
Neurons of brain and in synapses where axons connect to muscles and body organs
Which is true of David Hubel and Torsten Wiesel's studies measuring response of indiv neurons in primary visual areas?
Neurons respond when a contrast between light and dark occurs
Acetylcholine (ACh)
Neurotransmitter involved in voluntary motor control among other things like regulation of attention, learning, sleeping, dreaming, and memory
Dopamine
Neurotransmitter regulating motor behavior, motivation, pleasure, and emotional arousal
What happens to neurotransmitters left in synapse after chemical message is relayed?
Neurotransmitters leave synapse through three processes: 1. Reuptake: neurotransmitters reabsorbed by terminal buttons of presynaptic neuron's axon 2. Destroyed by enzymes in enzyme deactivation (specific enzymes break down specific neurotransmitters) 3. Neurotransmitters can bind to receptor sites called autoreceptors on presynaptic neurons (detect how much neurotransmitter has been released into synapse and tell neuron to stop releasing neurotransmitter when excess is present)
What advantages does fMRI have over pet/
No exposure to radioactive substance Localize changes in brain activity across briefer periods
What are the two neurotransmitters that influence mood and arousal?
Norepinephrine and serotonin
Having low levels of which two chemicals can cause mood disorders?
Norepinephrine and serotonin; mood, impulsivity, aggression, appetite
For which have researchers not found specialized neurons?
Numbers
Beta blocker
Obstructs receptor site for norepinephrine in the heart; helps people with increased or irregular heartbeat as well as to those with stage fright
Where is Na+ more concentrated in during resting potential? Action potential?
On the outside during resting; inside during action
What technique did David Hubel and Torsten Wiesel use?
One that inserted electrodes into occipital lobes of cats and observed patterns of action potentials and individual neurons -> DID NOT INITIALLY WORK (tried to amplify action potential signals, flash lights, etc with no response) -> Project glass slide in front of cat's eyes == neurons in primary visual cortex activated whenever contrast between light and dark (shadow of glass slide)
Tectum
Orients an organism in the environment; receives stimulus input from eyes, ears, and skins and moves organism in coordinated way toward stimulus
Cerebral cortex
Outermost layer of he brain, visible to the naked eye and divided into two hemispheres
The ___________ nervous system helps the body return to resting after dealing with a threat
Parasympathetic
How is sexual behavior related to the sympathetic and parasympathetic nervous systems?
Parasympathetic nervous system: Erection Sympathetic: Ejaculation Parasympathetic: Vaginal lubrication Sympathetic: Organism
The __________ lobe processes info about touch
Parietal
Striatum
Part of basal ganglia; involved in control of posture and movement
Resting state functional connectivity
Participants rest while fMRI measurements are made; measures extent to which spontaneous activity in diff brain regions is correlated over time
Receptors
Parts of cell membrane (of receiving neuron) that receive neurotransmitters and either initiate or prevent a new electric signal
What injury to what person helped shine new light on the emotional functions of the frontal lobes?
Phineas Gage's accident in which rod went through frontal lobe; complete change in personality
Bryan wants to learn about how the brain has evolved in humans. To investigate this, he should study the ______ of the brain.
Phylogeny
A split-brain patient is shown a frog in her right visual field. She is asked to identify what she sees. She would most likely be able to __
Point to the frog with her left hand
What happens to a spinal injury higher up the cord?
Poorer prognosis Ex: Quadriplegia (loss of sensation and motor control over all limbs), breathing through respirator, lifelong immobility
Amphetamine
Popular drug that stimulates release of norepinephrine and dopamine
What are the two aspects of development to consider when trying to understand the central nervous system?
Prenatal development (growth from conception to birth) and evolutionary development
The sympathetic nervous system:
Prepares the body for action in threatening situations
How does a neuron communicate with another neuron?
Presynaptic neuron has K+ and Na+ flowing across it -> action potential travels down length of axon to terminal buttons -> stimulates release of neurotransmitters from vesicles into synapse -> float across and bind to receptor sites on nearby dendrite of receiving neuron (postsynaptic neuron)
GABA (Gamma-aminobutyric acid)
Primary inhibitory neurotransmitter in brain; stops firing of neurons
Degree of relatedness
Probability of sharing genes: Children share half genes w each parent; quarter with grandparents; an eighth with cousins, etc
Cardiovascular exercise affects brain structures in nonhuman animals by
Promoting neuron growth and increased synaptic connections in the hippocampus
Human Connectome Project
Provide complete map of the connectivity of neural pathways in the brain
Functional brain imaging
Provides info about activity of brain when people perform various kinds of cognitive or motor tasks
Dendrites
RECEIVE information from other neurons and relay it to the cell body
Genes set the ____ in populations within a given environment.
Range of variation
Sensory neurons
Receive information from the external world and convey information to the brain via the spinal cord; specialized endings on dendrites that receive signals for light, sound, etc
Primary auditory cortex
Receives sensory info from the ears based on frequencies of sounds
Fusiform gyrus
Region near border of temporal and occipital lobes that helps with identification of faces
The reticular formation is a small cluster of neurons that __________
Regulates sleep, wakefulness, and levels of arousal
Thalamus
Relays and filters info from the senses and transmits the info to the cerebral cortex
A battery that is not connected to anything is a good analogy for the _______ of a neuron
Resting potential
The process that occurs when the presynaptic terminal buttons reabsorb a neurotransmitter is referred to as
Reuptake
Computerized axial tomography (CT) scan
Scanner rotates device around person's head and takes X-ray photos and then these photos are combined to get all angle; show densities of tissue (denser = whiter)
An area of the brain called the amygdala shows activation when a person:
Sees something emotional
What do too much glutamate and too little GABA cause?
Seizures
SSRIs
Selective serotonin reuptake inhibitors; block reuptake of neurotransmitter serotonin
Feature detectors
Selectively respond to certain aspects of a visual image; identify basic dimensions of stimulus Ex: only fire when detecting vertical line; 45 degree angle, etc
How is the pituitary gland related to our response to stress?
Sense threat -> sensory neurons send signals to hypothalamus -> stimulates release of adrenocorticotropic hormone (ACTH) from pituitary gland -> stimulates adrenal glands to release hormones that activate sympathetic nervous system (flight or fight response)
What are the three major types of neurons?
Sensory neurons, motor neurons, interneurons
What are the three levels of function that the cerebral cortex can be understood at?
Separation into two hemispheres, functions of each hemisphere, role of specific cortical areas
A person suffering from depression may be suffering from low levels of norepinephrine and _________, because both of these are involved in mood and arousal
Serotonin
What is LSD structurally very similar to?
Serotonin; binds with serotonin receptors in brain and produces similar effects on thoughts, feelings, and behaviors
Tarik was raised in a very stressful family situation in which he was abused by an alcoholic father and received very little attention from his mother. Jarrell was raised in a loving family in which he was not exposed to situations that produced a great deal of stress. According to Michael Meaney's research cited in the text, Tarik may experience a decrease in the neurotransmitter _____ in the hippocampus and an increase in DNA methylation of _____. This will make it more difficult for him to handle stressful situations.
Serotonin; gloucocorticoid receptor gene
Autonomic nervous system (ANS)
Set of nerves carrying involuntary and automatic commands that control blood vessels, body organs, and glands
Somatic nervous system
Set of nerves conveying info between voluntary muscles and central nervous system Ex: Anything humans have conscious control over; reaching for cup of coffee
Sympathetic nervous system
Set of nerves preparing the body for action in challenging or threatening situations
What are the five parts of the subcortical structures?
Thalamus, hypothalamus, pituitary gland, limbic system, basal ganglia
Hindbrain
The area of the brain coordinating info coming into and out of the spinal cord; looks like a stalk on which the rest of the brain sits
How does voluntary movement work in connection with the central nervous system?
The brain sends commands for voluntary movement through spinal cord to motor neurons -> skeletal muscles
What is at the top of the CNS?
The brain, which contains structures that support the most complex functions of the nervous system
What is behind the medulla?
The cerebellum
Which part of the hindbrain coordinates fine motor skills?
The cerebellum
What part of the brain orchestrates the movements that keep you steady on a bike?
The cerebellum; allows for graceful execution of actions
What are the two sections of the forebrain?
The cerebral cortex and subcortical structures
What does the resting potential arise from? Describe the ion state at resting potential.
The difference in concentrations of ions; resting state is high concentration of positively charged ion potassium (K+) and negatively charged protein ions (A-) INSIDE neuron's cell; OUTSIDE there are lots of positively charged sodium ions (Na+) and negatively charged chloride ions (Cl-) -> K+ concentrations is controlled by channels in cell membrane; resting state they flow freely while Na+ and other ions' channels are closed -> K+ move out of neuron through open channels; resting potential is potential energy
What did researchers learn from Phineas Gage's accident?
The frontal lobe is involved in emotional regulation, planning, and decision making
What are the structures that the hindbrain is composed of?
The medulla, the reticular formation, the cerebellum, the pons
Which of the brain is involved in movement and arousal?
The midbrain
What is the midbrain the central location of?
The neurotransmitters involved in arousal, mood, and motivation and brain structures that rely on them
Postsynaptic neuron
The receiving neuron
What can the motor and somatosensory cortices be compared to?
The sending and receiving areas of the cerebral cortex, taking in info and sending out commands
Presynaptic neuron
The sending neuron; the neuron through which K+ and Na+ are currently flowing across through
Neural rube
The structure formed in prenatal development when the ridges fold together and fuse to enclose the groove; tail end remains a tube and forms basis of spinal cord
If the dendrites of a neuron were compared to a telephone receiver, then the soma could be compared to:
The switchboard
What is something we've learned about motion perception from Transcranial magnetic stimulation?
The visual cortex CAUSES motion perception; if you stimulate visual cortex, you become unable to detect motion of object while you can still recognize that object
Who can the modern history of neuroscience be dated back to?
The work of Paul Broca; "Tan" man who lost ability to produce spoken language, but not the capacity to understand it due to damage in small area in left frontal lobe Opposite occurrence = Carl Wernicke (impairment in comprehension, but not ability to produce speech) Left hemisphere
What did Cajal observe about the dendrites and axons?
They don't actually touch each other -> Small gap between axon of one neuron and dendrites of another (synapse)
What were scientists surprised by when observing the squid's neurons (HINT: has to do with charge?)
They measured the action potential at charge of +40 mV, which is well above zero NOT simply loss of -70 mV resting potential because this would only have brought charge back to zero
What effect do noepinephrine and dopamine have on the body?
They play a critical role in mood control; increases in either result in euphoria, wakefulness, and a burst of energy. Noepinephrine increases heart rate so an overdose can cause the heart to contract so rapidly that heartbeats do not last long enough to pump blood effectively
How do many general anesthetics work?
They work by reducing activity in the reticular formation because the reticular formation maintains the same delicate balance between alertness and unconsciousness in humans
Refractory period
Time following an action potential during which a new action potential cannot be initiated; an imbalance of ions (lots of extra Na+ ions inside and a lot of extra K+ ions outside the axon)
What is a terminal button filled with?
Tiny vesicles containing neurotransmitters
Which behavior is the midbrain likely to be involved in?
Turning away from a gory scene in a movie
Purkinje cell
Type of interneuron that carries info from cerebellum to rest of brain and spinal cord; dense, elaborate dendrites resembling bushes
Bipolar cells
Type of sensory neuron found in retinas of eyes; single axon and single dendrites
Prozac
Used to treat depression; neurotransmitter agonist -> blocks reuptake of serotonin == part of selective serotonin reuptake inhibitors (SSRIs)
What group has the CNS organized into a hierarchy?
Vertebrate
The _______ nervous system is a set of nerves that conveys info into and out of the central nervous system and is a system that is consciously controlled
Voluntary
Saltatory conduction
When electric current passes down length of myelinated axon, charge jumps from node to node rather than having to traverse entire axon
Could you survive on only a hindbrain and midbrain?
Yes; hindbrain takes care of all bodily functions necessary to sustain life Midbrain would orient toward or away from pleasurable or threatening stimuli in the environment
Runner's high is due to
endorphins
A brain scanning method that identifies brain activity by applying magnetic pulses to the brain and detecting the twisting of hemoglobin molecules in the blood is referred to in its abbreviated form as a(n) _______
fMRI
