Key Concepts in Memory and Neurogenesis

adult neurogenesis

the birth of new neurons in adulthood

AMPA

When a synapse strengthens, an increase in the number of ___ type glutamate receptors is often seen on the surface of the post-synaptic membrane.

anterograde amnesia

loss of memory for events that occurred after a brain injury

Aplysia

a type of sea slug used to study memory-related changes in the nervous system

automatized behavior (habit)

behavior that can be performed with little attention as a result of practice

basal ganglia

the group of brain structures which includes the striatum and is involved in habit formation

area CA1

a region of the hippocampus that receives input from area CA3

area CA3

A region of the hippocampus that receives input from the dentate gyrus

central nucleus of the amygdala

a nucleus of the amygdala that sends output to activate fear circuitry

classical conditioning

a type of learning in which one stimulus is associated with another, for instance, a tone with food

concept neuron

a neuron that represents information about a specific person, place or thing

conditioned response (CR)

a learned response to a conditioned stimulus

conditioned stimulus (CS)

a stimulus that comes to trigger a conditioned response as a result of classical conditioning

consolidation (of memory)

the process by which changes in the brain lead to long-term storage of a memory

dentate gyrus of the hippocampus

a region of the hippocampus that receives input from the entorhinal cortex

enriched environment

an environment, often containing novel objects and playmates, that increases neurogenesis

episodic memory

a kind of memory that is conscious and that pertains to a personal experience

explicit memory

a memory that can be consciously recalled

fear conditioning

a type of learning involving the association between a previously neutral stimulus and a feared (aversive) stimulus

habituation

learning to ignore a sensory event that is repeated many times

Hippocampal memory indexing theory

a theory of the hippocampus' role in memory retrieval that proposes that the cortex stores information about remembered events, and the hippocampus keeps track of which cortical neurons store the information for a given memory

hippocampus

a brain structure in the medial temporal lobes that is critical for episodic memory

implicit memory

memories that influence behavior, but which are not conscious

Korsakoff syndrome

a memory disorder associated with alcoholism

lateral amygdala

the nucleus of the amygdala that receives sensory information from the thalamus and cortex, and sends output to the central amygdala

lateral hypothalamus

When the central amygdala becomes active, it may, in turn, activate the ____ which generates sympathetic nervous system activity such as elevated heart rate.

locus coeruleus

When the central amygdala becomes active, it may, in turn, activate the ____ which increases vigilance.

long-term depression (LTD)

a long-term weakening of the synapse

long-term potentiation (LTP)

a long-term strengthening of the synapse

medial temporal lobe

the region of the temporal lobe containing the hippocampus and amygdala

neuronal assembly

a set of neurons with strong recurrent excitatory connections, which represent an item of information or a learned skill

NMDA receptor

When Ca++ flows into a neuron through a(n) ____ -type glutamate receptor, a synapse may strengthen.

periaqueductal gray

When the central amygdala becomes active, it may, in turn, activate the _____, which generates freezing/immobility of body parts.

place cells

neurons that are most active when one is in a particular environmental location

place field

the region of the environment that activates a place neuron

prefrontal cortex

an anterior region of the frontal cortex associated with attention, and which becomes active during early stages of learning a motor skill.

reciprocal connections

If neuron A sends signals to neuron B, and neuron B sends signals to neuron A, the two neurons have reciprocal connections.

reconsolidation

a process that restabilizes a memory that has been destabilized through memory retrieval

retrieval cue

something in the environment that brings a memory to mind

retrograde amnesia

loss of memory for events that occurred before a brain injury

retrograde messenger

a chemical signal that moves backwards across the synapse from the postsynaptic neuron to the presynaptic neuron

semantic memory

memory for facts

skill memory

a memory for how to do things (e.g., how to ride a bicycle)

startle response

an automatic defensive response to a sudden or threatening stimulus, such as a sudden, loud noise

striatum

a key area of the basal ganglia that plays a role in habit formation

synaptic plasticity

a change in the strength of a synapse

temporally graded (retrograde amnesia)

a kind of retrograde amnesia where severity of the amnesia depends upon the age of the memory (retrieval of the oldest memories is least affected)

unconditioned response (UR)

the response to an unconditioned stimulus

unconditioned stimulus (US)

a stimulus that produce an innate response

working memory

the kind of memory that actively keeps information in mind (until one is distracted)