NBL Module 12

Ancient Greeks on Memory

• conceptualized memory as akin to inscribing information on tablets, reflecting the practice of recording knowledge on physical media like stone or wax.

• This analogy emphasized the permanence and tangibility of memories, suggesting that once something is written in the mind, it remains fixed unless deliberately erased or altered.

Medieval society on memory

• likened memory to hydraulics, viewing the flow of information as analogous to the movement of water through pipes and valves.

• This perspective highlighted the dynamic nature of memory, emphasizing the role of channels and control mechanisms in directing the flow of thoughts and experiences within the brain.

17th century on memory

• memory was compared to the workings of a clock, with intricate gears and mechanisms representing the interaction of different cognitive processes.

• This mechanical analogy underscored the precision and complexity of memory functions, illustrating how different components must work in harmony to maintain accurate and reliable recollections.

20th century on memory

• memory was often likened to computer data storage, reflecting the era's technological advancements and the rise of digital information systems.

• This analogy emphasized the idea of memory as a structured, accessible, and manipulable repository of information, capable of being encoded, stored, and retrieved much like data in a computer.

Engrams

• considered the physical manifestation of memory in the brain, representing the specific neural circuits where information is stored.

• These memory traces involve biochemical changes and synaptic modifications that encode experiences and knowledge, forming the basis of long-term retention and recall.

APs in memory

• Action potentials (APs) use a form of binary code to transmit information, similar to the ones and zeros in computer systems, facilitating the storage and processing of memories.

• This coding mechanism allows for the precise communication of signals between neurons, underpinning the complex networks that support various types of memory.

Memory encoding

• the initial stage of memory processing, involving the reception, processing, and combination of sensory information into the central nervous system.

• not only involves the transformation of stimuli into neural signals but also the integration of these signals into meaningful patterns that can be stored and recalled later.

Memory storage

• refers to the maintenance of encoded information over time, creating lasting records that can be retrieved when needed.

• involves stabilizing and consolidating memories through biochemical and structural changes in the brain, ensuring that information remains accessible for future use.

Memory retrieval

• also known as recall or recollection, is the process of accessing stored memories in response to specific cues, allowing individuals to use past experiences to inform current thoughts and actions.

• relies on the reactivation of neural circuits that were involved in the original encoding, facilitating the reconstruction of memories.

• the process of accessing and bringing stored information back into conscious awareness.

• Effective _________ relies on cues, the organization of memories, and the brain’s ability to re-activate the neural circuits involved in the original encoding.

Sensory memory

• a brief retention of sensory information, allowing individuals to process and interpret stimuli even after the initial exposure has ended.

• This type of memory acts as a temporary buffer, holding detailed impressions for milliseconds to seconds, and serves as the first step in the formation of more enduring memories.

• holds vast amounts of detailed sensory information but decays quickly (within milliseconds to seconds).

• is modality-specific, with different sensory systems involved (e.g., visual, auditory, haptic). It can be either conscious or unconscious and does not require sustained attention.

Short-term memory

• holds a limited amount of information for a few minutes, enabling immediate recall and manipulation of data.

• This type of memory is essential for everyday tasks, such as remembering a phone number long enough to dial it, and can be enhanced through techniques like rehearsal and chunking.

• involves the temporary storage of a limited amount of information, typically about seven items, for around 15–20 seconds.

• requires attention and interacts with sensory memory for encoding and recall.

• The prefrontal cortex plays a significant role.

Long-term memory

• stores information for extended periods, ranging from days to a lifetime, and is crucial for maintaining a continuous sense of self and accumulated knowledge.

• This form of memory involves the stabilization and consolidation of neural circuits, allowing for the durable retention of skills, experiences, and information.

• characterized by an almost unlimited capacity for storing information for extended periods, from hours to a lifetime.

• does not involve persistent neural activity but relies on biochemical and structural changes to neurons and synapses for storage and retrieval.

Atkinson-Shiffrin model

• posits that memory consists of three distinct systems: sensory memory, short-term memory, and long-term memory, with information flowing through these stages sequentially.

• According to this model, sensory information is first captured briefly, then transferred to short-term memory through attention, and finally encoded into long-term memory if deemed important.

Iconic memory

• a component of sensory memory

• retains a high-resolution visual representation of stimuli for a brief duration, typically less than a second.

• This fleeting storage allows the brain to quickly scan and process visual information, facilitating rapid recognition and response to changes in the environment.

Echoic memory

• the auditory counterpart to iconic memory, holds auditory information for several seconds, enabling the brain to integrate and interpret sounds over time.

• This form of memory is essential for understanding spoken language and other auditory signals, as it allows for the temporary storage and sequential processing of auditory input.

Haptic memory

• involves the retention of tactile sensations, allowing individuals to remember and process touch-related information for a brief period, typically around two seconds.

• This type of memory plays a critical role in perceiving and responding to physical contact, contributing to the overall sensory experience.

Working memory

• the cognitive system responsible for temporarily holding and manipulating information needed for complex tasks such as reasoning, learning, and comprehension.

• It involves the active use of short-term memory stores, facilitated by the prefrontal cortex and other brain regions, to support ongoing mental activities and problem-solving.

Central executive

• a component of working memory that oversees and coordinates the cognitive processes involved in focusing attention, managing tasks, and integrating information.

• This executive function controls the flow of information between short-term and long-term memory, ensuring that relevant data is available for decision-making and action.

Phonological loop

• a subsystem of working memory that specializes in storing and rehearsing verbal and auditory information.

• consists of a phonological store, which holds sounds and words, and an articulatory rehearsal process, which refreshes and maintains this information through subvocal repetition.

Visuo-spatial sketchpad

• a component of working memory that manages and manipulates visual and spatial information, aiding in tasks such as navigation, visualizing objects, and understanding spatial relationships.

• allows for the temporary storage and processing of visual and spatial data, facilitating activities that require mental imagery and spatial awareness.

Declarative memory

• also known as explicit memory, is the type of memory that can be consciously recalled and explained to others.

• encompasses knowledge of facts and events, and is critical for tasks such as discussing past experiences or answering trivia questions.

• includes two subdomains: semantic memory and episodic memory. These subdomains are essential for storing and recalling different types of information and experiences.

• (explicit memory) involves the conscious recall of facts and events, including semantic (general knowledge), episodic (personal events), and spatial memory.

• rely heavily on the medial temporal lobe, including the hippocampus.

Semantic memory

• involves the storage of general knowledge, facts, and concepts that we learn, such as vocabulary, historical dates, and the names of people.

• This type of memory is crucial for academic learning and everyday factual recall.

Episodic memory

• the ability to recall specific events or episodes from one's life, such as a recent vacation or a childhood birthday party.

• includes both autobiographical events and witnessed external events, providing a rich narrative of personal history.

Medial temporal lobe

• including the hippocampus and entorhinal cortex, is essential for the formation and encoding of both semantic and episodic memories.

• This brain region also plays a critical role in spatial memory and navigation.

Hippocampus

• a part of the allocortex, is crucial for declarative and spatial memory formation.

• contains GABAergic and glutamatergic neurons and has a unique 3 to 4-layered structure that supports its role in memory processing.

• plays a key role in encoding new declarative memories, especially spatial and episodic memories.

• facilitates synaptic consolidation and early systems consolidation, transferring these memories to the cerebral cortex for long-term storage.

Entorhinal cortex

• a type of cerebral cortex that projects the majority of its information into the hippocampus.

• lacks the typical neocortical layered structure and is pivotal in the transmission of sensory and motor information to the hippocampus.

Spatial memory

• involves the ability to remember the locations of objects, the layout of environments, and the spatial relationships between objects.

• The medial temporal lobe, particularly the hippocampus and entorhinal cortex, is heavily involved in this type of memory.

Types of cortex

• The hippocampus is categorized as allocortex, specifically archicortex, unlike the neocortex which has six layers.

  The olfactory cortex is another example of the archicortex, and these regions contain fewer layers and different types of neurons compared to the neocortex.

Memory formation

• involves synaptic consolidation, where biochemical and morphological changes occur at synapses in response to information processing.

• This process is crucial for transferring information from short-term to long-term memory storage.

Memory retrieval

• Once memories have been consolidated in the neocortex, the hippocampus is no longer required for their ______.

• However, the hippocampus continues to be essential for encoding new memories and integrating them with existing knowledge.

Implicit memory

• also known as non-declarative memory, involves the unconscious recall of skills and procedures, such as riding a bike or playing an instrument.

• This type of memory requires different brain regions, such as the striatum and cerebellum, for motor learning and procedural memory.

• includes procedural memory (skills and tasks), classical conditioning (emotional and reflexive), and priming (prior exposure influences perception).

• involves brain areas such as the striatum, amygdala, and cerebellum.

Emotional memory

• heavily influenced by the amygdala, a subcortical structure located close to the hippocampus.

• The amygdala is involved in processing _________ inputs and linking them to memories, enhancing the recall of emotionally charged events.

Synaptic consolidation

• refers to the biochemical and morphological changes at synapses that occur in response to incoming information.

• This process is vital for the long-term stabilization of memory traces within neural networks.

• refers to the initial stabilization of newly formed memories in the hippocampus before they are transferred to the cortex for long-term storage.

• thought to be facilitated by long-term potentiation (LTP).

Systems consolidation

• involves the transfer of information from the hippocampus to other circuits within the neocortex.

• This process ensures the integration and long-term storage of memories across different regions of the cerebral cortex.

H.M. (Henry Molaison)

• a patient who underwent a bilateral medial temporal lobectomy to treat epilepsy

• was unable to form new long-term memories following the surgery.

• His case provided significant insights into the role of the hippocampus in memory formation, particularly in understanding anterograde amnesia.

Hippocampal formation

• includes the CA regions and the dentate gyrus, has a structure similar to the rest of the neocortex.

• plays a crucial role in the processing and integration of sensory and motor information, as well as in memory encoding and spatial navigation.

LTP (Long-term potentiation)

• a process that involves the strengthening of synapses based on recent patterns of activity.

• It is a key mechanism underlying synaptic plasticity and memory encoding, particularly within the hippocampus.

• refers to the long-term increase in synaptic strength following high-frequency stimulation of one neuron by another.

• It is a key process in synaptic plasticity, particularly in learning and memory.

• The phenomenon has been widely studied in rodent hippocampal Schaffer collaterals and is characterized by a persistent increase in synaptic response, observed after tetanic stimulation.

• an activity-dependent increase in the strength of synaptic responses that lasts for 30 minutes to several hours, potentially extending into days or weeks. It is believed to be a cellular mechanism underlying learning and memory.

Electrophysiological studies

• involve recording electrical activity in neurons to understand synaptic responses and plasticity.

• Techniques such as extracellular recordings allow scientists to measure changes in synaptic strength and investigate mechanisms of LTP.

Hippocampal circuitry

• includes pathways such as the perforant pathway, mossy fiber pathway, and Schaffer collateral pathway

• is essential for transmitting and processing information within the hippocampus.

• This circuitry supports the encoding, consolidation, and retrieval of declarative and spatial memories.

Field potentials

• the summed electrical signals from multiple dendritic responses.

• They are recorded in regions like the hippocampus to study synaptic activity.

• reflect the overall activity of a population of neurons and are useful for observing changes in synaptic strength during plasticity events like LTP.

Tetanic stimulation

• refers to a form of stimulation involving high-frequency bursts (often 100 Hz) applied to axons, resulting in an increase in synaptic response.

• This stimulation paradigm is used to induce LTP in hippocampal neurons.

• causes a transient but significant enhancement in the postsynaptic response following a few pulses of stimulation.

Low-frequency Stimulation (LFS)

• a type of stimulation characterized by repeated, low-frequency pulses (typically tens or hundreds of stimuli).

• This stimulation typically results in long-term depression (LTD) of synaptic responses in hippocampal neurons, which involves a decrease in the synaptic strength over time.

LTD (Long-Term Depression)

• the long-term decrease in synaptic strength, usually induced by low-frequency stimulation.

• In hippocampal neurons, it is induced when synaptic responses are diminished after prolonged, low-frequency stimulation.

• It plays a role in processes opposite to LTP, such as memory refinement and synaptic pruning.

Synaptic plasticity

• the ability of synapses to strengthen or weaken over time in response to activity.

• It is considered the biological basis for learning and memory.

• LTP and LTD are two primary types that occur in excitatory glutamatergic synapses throughout the brain, including in the hippocampus and cortex.

• involves biochemical and structural changes in synapses, including changes in receptor density and synapse formation.

• plasticity is a key mechanism underlying learning, memory, and experience.

Hebbian learning

• refers to a principle where the synaptic strength between two neurons is increased when they are activated simultaneously or within a short time frame.

• This process is summarized by the phrase "cells that fire together wire together," forming the foundation for synaptic plasticity and learning.

NMDA receptors

• a type of glutamate receptor critical for inducing LTP. They are ion channels that require both glutamate binding and membrane depolarization to open.

• When opened, NMDA receptors allow calcium ions to enter the postsynaptic cell, initiating the molecular cascades that lead to LTP.

AMPA receptors

• another type of glutamate receptor that mediate fast synaptic transmission.

• Unlike NMDA receptors, AMPA receptors do not require depolarization to open, and they primarily allow sodium ions to flow into the cell, contributing to excitatory postsynaptic potentials (EPSPs).

Calcium influx

• refers to the entry of calcium ions (Ca2+) into the postsynaptic neuron through NMDA receptors, a crucial event in the induction of LTP.

• The increased calcium concentration triggers downstream signaling processes that enhance synaptic transmission and strengthen the synapse.

Protein kinases

• enzymes that phosphorylate proteins, altering their activity or function.

• In LTP, they are activated by calcium influx through NMDA receptors, and they play a key role in the early phase of LTP by modifying existing proteins involved in synaptic plasticity.

Post-Tetanic Potentiation

• a brief but significant enhancement of synaptic response observed immediately after tetanic stimulation.

• results in an increase in synaptic strength that decays over time, playing a role in the short-term enhancement of synaptic transmission that precedes LTP.

Early phase of LTP (E-LTP)

• occurs within minutes after the induction of LTP, involving the activation of protein kinases and phosphorylation of pre-existing proteins.

• This phase does not require new protein synthesis but leads to rapid changes in synaptic response and is critical for initial memory encoding.

Late phase of LTP (L-LTP)

• a prolonged phase that lasts for hours and requires new protein synthesis.

• involves the transcription of new mRNA and the production of proteins that contribute to the long-term strengthening of synapses and persistent memory storage.

Serine/Threonine Kinases

• a group of protein kinases involved in the early phase of LTP.

• These kinases phosphorylate proteins at serine or threonine residues, modulating their activity and function in response to synaptic stimulation, ultimately enhancing synaptic transmission

Tyrosine kinases

• a class of protein kinases that phosphorylate tyrosine residues in proteins.

• In the late phase of LTP, they play a critical role in regulating the activity of proteins involved in synaptic strengthening and memory consolidation.

Synapse-specific plasticity

• refers to the phenomenon where only the synapses that are actively involved in the stimulation are modified, either potentiated or depressed.

• This specificity ensures that only relevant synaptic connections are strengthened or weakened during learning processes.

Theta Burst Stimulation (TBS)

• a form of stimulation involving short bursts of pulses (typically 4 pulses) at a frequency that mimics the natural theta rhythm observed in hippocampal activity.

• has been shown to produce LTP and is considered more physiologically relevant compared to tetanic stimulation.

Synaptic efficacy

• refers to the ability of a synapse to transmit an action potential from the presynaptic to the postsynaptic neuron.

• In the context of LTP, this increases as a result of enhanced synaptic strength following activity-dependent changes in synaptic function.

Coincident pre and post-synaptic activity

• refers to the requirement for both presynaptic and postsynaptic neurons to be active simultaneously or within a short window of time to induce LTP.

• This synchronous firing is key for the induction of synaptic plasticity.

Memory process

• the process by which information is encoded, stored, and retrieved.

• involves three stages: encoding, where information is received and processed; storage, where a permanent record is created; and retrieval, where stored information is called back when needed for a task.

Hebb’s postulate

describes the process by which simultaneous activation of both presynaptic and postsynaptic neurons strengthens the synaptic connection between them, a concept central to LTP and learning.

Baddeley & Hitch Model

• The central executive, phonological loop, and visuo-spatial sketchpad are components of this model of working memory.

• The central executive controls information flow, while the phonological loop stores verbal information and the visuo-spatial sketchpad handles visual and spatial information.

Episodic buffer

added to Baddeley's model in 2000, temporarily stores information from long-term memory that is relevant to a task, integrating it into working memory alongside the phonological loop and visuo-spatial sketchpad.

Procedural memory

• part of non-declarative memory, stores information related to skills and actions, such as riding a bike or playing an instrument.

• involves structures like the striatum and cerebellum.

neural circuits

This concept suggests that long-term memories are distributed across networks of neurons in the cerebral cortex, which work together to represent specific memories, facilitating retrieval and recall.

persistent firing

In learning and memory, ____________ of neurons in networks (especially in the prefrontal cortex and hippocampus) supports the maintenance of information in working memory, allowing for short-term storage and manipulation.

Hippocampal pathways

• The perforant pathway, mossy fiber pathway, and Schaffer collaterals are key circuits in the hippocampus involved in transmitting information between brain regions critical for memory formation.

• These pathways allow for synaptic changes, such as LTP, to encode memories.

All of these answers

Memory is the cognitive function that has been most intensely studied and yielded the most mechanistic information because ______.

Animal model studies have been used extensively to study memory

All of these answers

Of its clinical importance in dementia, neurodevelopmental disorders, and brain injury

It is important for identity formation and defining a sense of self

Specific human brain injuries affect specific types of memory

All of these answers

The most important implication(s) of the Atkinson–Shiffrin model (also known as the multi-store model or modal model) is that ______.

Long term memory depends on sensory and short term working memory

The stages of memory might involve different mechanisms

There are different stages of memory with different characteristics

It provided a framework for memory that stimulated memory research

All of these answers

Engrams

______ are hypothesized to be means by which memories are stored as biophysical or biochemical changes in the brain.

Encodons

Semantics

Engrams

Mnemonics

Imprints

Encoding

Learning and acquisition are synonymous with memory ____.

Activation

Retrieval

Encoding

Stabilization

Access

It is modality specific

Which of the following BEST DESCRIBES sensory memory?

It has a low capacity

It can be prolonged by rehearsal

It is always conscious

It is modality specific

It decays slowly

The prefrontal cortex, posterior parietal cortex, and temporal cortex

Short term working memory mainly involves which brain region(s)?

Only the hippocampus

Only the posterior parietal cortex and temporal cortex

Only the prefrontal cortex

The prefrontal cortex, posterior parietal cortex, and temporal cortex

All regions of the frontal, parietal, and temporal lobes

Reverberating neuronal circuit activity

The mechanisms underlying short term working memory involve predominantly ____.

Reverberating neuronal circuit activity

Short term changes in protein kinase and phosphatase activity

Biochemical and epigenetic mechanisms

Transcription and translation

Short term rewiring of synapses and circuits

Semantic store

In the revised Baddley Hitch model of working memory, the central executive is the supervisory system, and all of the following are subservient systems EXCEPT the ____.

Phonological loop

Visuo-spatial sketchpad

Semantic store

Episodic buffer

Mind's eye

The visuospatial sketch pad has also been called the _____.

Mind's eye

Window into the mind

Bind spot

Third eye

Hallucination network

Involves long term biochemical and morphological changes to synapses and circuits

Which of the following BEST DESCRIBES long term memory? Long term memory

Involves long term biochemical and morphological changes to synapses and circuits

Has a limited capacity

Is modality specific

Requires most areas of the cerebral cortex for encoding memory

Involves two main types, called declarative and explicit memory

All of these answers

In the multi-store model (also known as Atkinson–Shiffrin memory model), information is lost or forgotten from ____.

Long term memory

Short term working memory

All of these answers

Sensory memory

Areas of the cerebral cortex

The majority of long term memories are thought to be stored in many ____.

Parts of the basal ganglia

Structures of the medial temporal lobe

Areas of the cerebral cortex

Regions of the hippocampus

Domains of the cerebellum

The medial temporal lobe is involved in encoding declarative memory

Which of the following BEST DESCRIBES long term memory encoding?

The medial temporal lobe is involved in encoding declarative memory

The cerebellum is involved in encoding executive memory

The prefrontal cortex is involved in encoding procedural and motor memory

The basal ganglia is involved in encoding emotional memory

The amygdala is involved in encoding procedural memory

It is involved in spatial memory and spatial navigation

Which of the following BEST DESCRIBES the hippocampus?

It consists of several layers of neocortex called cornu ammonis (CA)

It is involved in spatial memory and spatial navigation

It is involved in auditory processing and language production

It is required for the encoding of long term implicit memory

It is located in the lateral temporal lobe

All of these answers

Studies on Henry Moliason (patient HM) demonstrated that the hippocampus and nearby temporal lobe structures are____.

All of these answers

Not required for encoding new procedural memories

Not required for short term working memory

Required for encoding new declarative (semantic and episodic) memories

Not required for retrieval of most previously stored semantic memories

The entorhinal cortex, brain stem and basal forebrain

Which brain regions have DIRECT inputs into the hippocampus?

Only the brain stem and basal forebrain

Only the sensory association cortices

The sensory association cortices and entorhinal cortex

Only the entorhinal cortex, perirhinal cortex, and parahippocampal cortex

The entorhinal cortex, brain stem and basal forebrain

The perirhinal cortex axons to parahippocampal cortex (pyramidal pathway)

The main neuronal circuits into and within the hippocampus include all of the following EXCEPT ___.

The entorhinal cortex axons to DG neurons (perforant pathway)

The CA3 axons to CA1 neurons (Schaffer collateral pathway)

The perirhinal cortex axons to parahippocampal cortex (pyramidal pathway)

The DG axons to CA3 neurons (mossy fiber pathway)

Glutamatergic excitatory

What types of neurons are dentate granule, CA1 and CA3 neurons, and what types of synapses do they form?

Glutamatergic excitatory

GABAergic inhibitory

Monoaminergic modulatory

Cholinergic modulatory

All of these answers

Subiculum

The main DIRECT output from the hippocampus is from CA1 to the ____.

Amygdala

Perirhinal cortex

Subiculum

All of these answers

Entorhinal cortex

All of these answers

The hippocampus can provide significant output information DIRECTLY or INDIRECTLY to the _______.

All of these answers

Subiculum

Septum

Entorhinal cortex

Amygdala

The entorhinal cortex

An important function for the subiculum is to provide input back to ________ which ensures the continued processing of information by the hippocampus.

The dentate gyrus

The entorhinal cortex

The brainstem and thalamus

All of these answers

CA3 and CA1 dendrites

Episodic and rich contextual

It has been hypothesized that the hippocampus is required for both the encoding AND retrieval of some ______ memories.

Short term working

Semantic and spatial

Episodic and rich contextual

Procedural and reflex

Emotional

Synaptic strength/response

Long term potentiation (LTP) is defined as an activity dependent increase in _______that persists for 30 minutes or more.

Sensory transmission/perception

Circuit/network activity

Synaptic strength/response

Consolidation/reconsolidation

Hippocampal activation/reactivation

Long term memory

LTP is thought to be a neuronal mechanism involved in ____.

Short term working memory

Sensory memory

Long term memory

All types of memory: sensory, short term working, and long term

Hippocampal-dependent memory

All of these answers

LTP has been demonstrated to occur in the ______.

CA1 neurons (Schaffer collateral pathway)

Striatum and cerebellum

All of these answers

Hippocampus and amygdala

Neocortex

Synapse/input specific

LTP is considered to be Hebbian or _____ because it occurs only when there is coincident activity in the presynaptic neuron and the postsynaptic neuron.

Wired

Dendritic

Reversible

Synapse/input specific

Persistent

Removal of the Mg2+ block from NMDA receptors

Which of the following BEST DESCRIBES LTP induction in the Schaffer collateral (CA3 axons to CA1 dendrites). It requires ____.

Removal of the Mg2+ block from NMDA receptors

Hyperpolarization of the postsynaptic membrane potential

Excitatory and inhibitory synapses

Release of glutamate and GABA from presynaptic axons

Activation of AMPA receptors, which allows the influx of Ca2+

Increase in postsynaptic Ca2+ levels

The key function for AMPA and NMDA receptors for LTP induction is the _____.

Depolarization of the membrane potential

All of these answers

Stimulation of action potentials

Activation of glutamate release

Increase in postsynaptic Ca2+ levels

All of these answers

The three types of stimulations for inducing (triggering) LTP are similar in that they share ____.

Presynaptic depolarization

Postsynaptic membrane depolarization

Presynaptic release of glutamate

All of these answers

Activation of postsynaptic NMDA receptors

Protein kinases

In early LTP (E-LTP) the function of Ca2+ is to rapidly activate ____.

Protein kinases

Protein proteases

Protein phosphatases

Protein synthesis

All of these answers

PP2A

Which of the following IS NOT one of the proteins activated in the previous question.

ERK

PKC

PP2A

CAMKII

PKA

AMPA receptors

In early LTP, the increased postsynaptic response (strength) primarily involves an increase in ______ at the synapse.

Glutamate transporters

NMDA receptors

All of these answers

AMPA receptors

Metabotropic glutamate receptors

All of these answers

The reason why the hippocampus is an ideal preparation to study LTP is because ___.

The circuitry of the hippocampus is well defined with identified inputs and outputs

The hippocampus can be removed and maintained for many hours

All of these answers

Studying plasticity in this region is relevant to declarative memory

LTP can be measured using extracellular field potentials from multiple dendrites

It can be prolonged by attention

Which of the following is NOT TRUE about sensory memory?

It decays rapidly

It can be prolonged by attention

It has a high capacity

It can be conscious or unconscious

It is modality specific