HW 7 Neuro

what are some requirements for early LTP?

-early phosphorylation of AMPARs -insertion of AMPARs

describe associative learning and two types

- behavior is altered by formation of associations between stimuli, responses and outcome - Happens every day and can be dysregulated by drugs of abuse -ex: dog associates doorbell ringing with stranger Two types: classical and operant conditioning

describe sensitization

- intensifies response to stimuli, even those that previously evoked little or no response -A strong and salient stimulus results in an exaggerated response to all subsequent stimuli Ex: Now suppose you're walking down the sidewalk on a well-lit city street at night, and suddenly there is a blackout. You hear footsteps behind you, and though this wouldn't normally disturb you, now you nearly jump out of your skin. Car headlights appear, and you react by side-stepping away from the street. The strong sensory stimulus (the blackout) caused sensitization, a form of learning that intensifies your response to all stimuli, even ones that previously evoked little or no reaction

Describe habituation

- repeated representation of the same stimulus produces a progressively smaller response -Ex: mouse is initially bothered by a noise; keep making noise --> eventually will get used to it

describe pre-synaptic short-term sensitization in aplysia?

-After tail shock, the serotonin is released onto presynaptic terminal of sensory neuron --> closes S-type K+ channel, prolongs AP and causes larger EPSP in motor neuron -the axon terminal of the siphon sensory nerve has metabotropic serotonin receptors; these are coupled to G-proteins --> activate adenylyl cyclase --> production of cAMP --> activate PKA --> phosphorylate S-type K+ channels causing them to close -When S-type channels close, they cannot participate in repolarizing membrane terminal --> prolongs AP and enhances influx of calcium into presynaptic terminal --> increased Ca2+ influx causes enhanced glutamate release from sensory neuron --> larger EPSP in motor neuron

describe non-associative learning and two types

-a change in behavioral response that occurs over time in response to a single type of stimulus Two types: habituation and sensitization

Describe the trisynaptic circuit of the hippocampus.

-entorhinal cortex sends info to hippocampus by way of a bundle of axons called the perforant path. The perforant path axons synapse on neurons of the dentate gyrus. Dentate gyrus neurons give rise to axons (Called mossy fibers) that synapse on cells in CA3. CA3 cells give rise to axons that branch. One branch leaves hippocampus via the fornix. The other branch, called the Schaffer collateral, forms synapses on the neurons of CA1. o Entorhinal cortex --> dentate gyrus (perforant path) synapses o Dentate gyrus --> CA3 (mossy fiber) synapses o CA3 --> CA1 (Schaffer collateral) synapses

what happens in long-term sensitization post-synaptically?

-larger or more tail shocks = greater 5HT release onto MOTOR neuron -5HT binds to G-protein receptor --> activates phospholipase C (PLC) --> hydrolyzes PIP2 into DAG and IP3 --> increased Ca2+ influx --> Ca2+ binds calmodulin --> activates CAMKII --> increased AMPA receptor insertion --> greater and longer lasting EPSP -CAMPKII can also activate CREB --> acts as TF in motor neuron --> activates transcription of immediate early genes (IEGs) --> trasncribe proteins that facilitate plasticity --> strengthens synapse

describe presynaptic long-term sensitization in aplysia?

-larger or more tail shocks = greater 5HT release onto SENSORY neuron -PKA increase closes K+ channels like before but there is more PKA now --> phosphorylation of CREB --> binds to DNA (TF) --> induces ubiquitin hydrolase --> increases PKA activity --> more K+ channels close --> longer depolarization --> longer time for vesicle release

what are some requirements for late LTP?

-phosphorylation (activation) of CREB -gene transcription -protein synthesis -morphological changes (increased synapse size, more release sites)

what happens post-synaptically in short term sensitization?

-siphon touch --> Ca2+ channel activation -tail shock --> 5HT release -siphon touch induces glutamate release --> increases Ca2+ influx in post-synaptic neuron --> more AMPA insertion (LTP)

facts about habituation

-stimulus-specific -weak stimuli habituate more than strong stimuli

what are experimentally shown requirements for LTP?

-synapses must be active at the same time that the postsynaptic cell is strongly depolarized, -calcium -NMDA receptors

facts about sensitization

-usually produced by strong stimuli -not stimulus-specific -thought to reflect general state of arousal or responsiveness

Bilateral temporal lobectomy such as that sustained by H.M. is characterized by which of the following? A) Permanent anterograde amnesia but intact procedural memory B) Permanent retrograde amnesia as well as procedural memory deficits C) Permanent anterograde amnesia as well as procedural memory deficits D) Permanent procedural memory deficits and transient anterograde amnesia

A) Permanent anterograde amnesia but intact procedural memory

According to research in monkeys using the delayed-match-to-sample task, hippocampus is needed for retaining memory A. For more than about 10s B. Of spatial locations C. For any length of time D. Of Jennifer Aniston

A. For more than about 10s

Which of these is most likely to impair memory A. Injecting NMDA antagonist immediately before training/learning B. Injecting NMDA antagonist immediately after training/learning C. Injecting NMDA antagonist immediately before testing/recall D. All of the above

A. Injecting NMDA antagonist immediately before training/learning

Memory required for animals to behave successfully in the delayed non-match to sample (DNMS) task is which of the following? A. Recognition memory B. Procedural memory C. Cognitive memory D. Long-term memory

A. Recognition memory

describe multiple trace theory

An alternative to the standard model of memory consolidation in which the hippocampus participates indefinitely in memory storage along with the neocortex; in this model, each time an episodic memory is recalled in a new context, an additional memory trace is formed. -every time you recall a memory, it becomes reactivated (reactivation = new memory) -memories recalled have more hippocampal traces -beacuse of these newly distributed traces, memory can survive partial but not complete damage to hippocampus **seems more accurate than standard because HM can recall remote memories

describe the standard model

An explanation of memory formation in which sensory information is processed by the hippocampus and later transferred to neocortex for permanent storage -initially, you need the hippocampus to acquire memories. Overtime, the cortical modules make links with each other, and hippocampus is no longer needed. Hippocampal memory trace is temporary -Overtime, a memory becomes represented by neocortical networks and hippocampus is no longer needed for retrieval

Neural recordings in human medial temporal lobe have uncovered cells selective for A. Low-level visual stimuli B. Jennifer Aniston C. Particular categories of objects D. B and C E. All of the above

B and C B. Jennifer Aniston C. Particular categories of objects

Which of the following statements correctly reflects the idea of memory consolidation? A) Memory consolidation is a mechanism used by declarative but not procedural memory. B) Memory consolidation converts short-term memories or sensory information into long-term memory. C) Memories can be consolidated for permanent storage in short-term memory. D) All short-term memories are eventually converted into a permanent form.

B) Memory consolidation converts short-term memories or sensory information into long-term memory.

What term best describes the process by which reactivating a memory makes it sensitive just as it had been immediately after the memory was first formed? A) Consolidation B) Reconsolidation C) Deconsolidation D) Differentiation

B) Reconsolidation

Which memory is LEAST likely to be impaired by a hippocampus lesion? A. Recently learned fear of a place B. Pavlovian tone-food association C. A taxi driver's ability to navigate Paris (without Waze) D. Your memory of the US state capitals

B. Pavlovian tone-food association

Efficient performance in the standard radial arm maze (never going down the same arm twice) appears to depend on which type of memory? A. Long-term memory B. Working memory C. Procedural memory D. All choices are correct.

B. Working memory

Which type of memory can be accessed for conscious recollection? A. Nondeclarative memory B. Procedural memory C. Declarative memory D. Classical conditioning

C. Declarative memory

How did Hebb define the cell assembly? A. All the cortical cells that are activated by any one of the senses B. All the cortical cells that are activated by the process of memory reconsolidation C. Neurons simultaneously activated by an external stimulus that are reciprocally interconnected D. Those cells being used at any given moment for working memory

C. Neurons simultaneously activated by an external stimulus that are reciprocally interconnected

What are hippocampal place cells? A. Neurons that fire when the subject remembers being in a specific place B. Neurons that fire when the animal successfully completes the Morris water maze C. Neurons that fire when the animal is in a specific location D. Neurons that are located in a specific location in the hippocampus

C. Neurons that fire when the animal is in a specific location

Systems consolidation refers to: A. Strengthening of synapses to form memory B. different psychological functions being performed by the same brain region C. a change over time in the brain regions storing a particular memory D. the fact that reactivated memories can be erased

C. a change over time in the brain regions storing a particular memory

Karl Lashley studied the effects of various-sized cortical lesions on maze performance in rats. He concluded that the memory deficits were correlated with the size of the lesion but not the location and hypothesized that all cortical areas contribute equally to learning and memory. What is the current interpretation of these experiments? A) Lashley's conclusions remain unchallenged. B) Nothing about Lashley's studies has stood the test of time. C) All cortical areas contribute equally to memory in rats but not in other species. D) All cortical areas do not contribute equally to memory, but memories are widely distributed.

D) All cortical areas do not contribute equally to memory, but memories are widely distributed.

A patient with brain trauma cannot remember events prior to the trauma. Which type of amnesia does this symptom indicate? A) Transient global amnesia B) Dissociated amnesia C) Anterograde amnesia D) Retrograde amnesia

D) Retrograde amnesia

Based on Squire's findings of studying the patient E.P., which of these statements is correct? A) The MTL is the permanent repository for spatial maps B) The MTL is essential for the retrieval of remote memories C) The MTL is not essential for the formation of long-term declarative memories D) The MTL is not essential for the retrieval of remote memories

D) The MTL is not essential for the retrieval of remote memories

Which kind of learning involves a change in behavioral response that occurs over time in response to a single type of stimulus? A. Classical conditioning B. Instrumental conditioning C. Associative learning D. Nonassociative learning

D. Nonassociative learning

Hebb's conclusions about the engram could explain Lashley's results. Yes No

YES

Describe classical conditioning

a previously neutral stimulus begins to elicit a response after pairing it with a stimulus that evokes an automatic response (US and UR, respectively)

what is most likely the cause of the presynaptic glutamatergic depression during habituation?

due to a reduction in number of synaptic vesicles available for release and inactivation of voltage-dependent calcium channels

Which of the following medial temporal lobe structures is important for declarative memory consolidation? A. Hippocampus B. Parahippocampal and rhinal cortical areas C. Fornix D. All choices are correct.

hippocampus, parahippocampal and rhinal cortical areas, fornix

describe operant conditioning

response-outcome learning - individual learns to associate a response (motor action like pressing level) with a meaningful outcome (i.e. a reward, such as food)