Learning and Memory Pt. I Flashcards
perceptual learning
Learning to recognize a particular stimulus.
Associative learning
Learning to automatically make a particular response in the presence of a particular stimulus; includes classical conditioning.
Learning which responses lead to reinforcement in the presence of certain cues, includes instrumental conditioning
Hebb rule
The hypothesis proposed by Donald Hebb that the cellular basis of learning involves strengthening of a synapse that is repeatedly active when the postsynaptic neuron fires.
dentate gyrus
Part of the hippocampal formation; receives inputs from the entorhinal cortex and projects to the filed CA3 of the hippocampus.
field CA1
Part of the hippocampus; receives inputs from field CA3 and projects out of the hippocampal formation via the subiculum.
field CA3
Part of the hippocampus; receives input from the dentate gyrus and projects to the field CA1.
Hippocampal circuit
preferment pathway to hippocampus:
ethelrhinal cortex–>dentate gyrus –>CA3–>CA1–>subiculum–>entorhinal cortex–>cerebrum
long-term potentiation (LTP)
A long-term increase in the excitability of a neuron to a particular synaptic input caused by repeated high-frequency activity.
hippopocampal formation
A forebrain structure of the temporal lobe, constituting an important part of the limbic system; includes the hippocampus proper (Ammon’s horn), dentate gyrus, and subiculum.
entorhinal cortex
A region of the limbic cortex that provides the major source of input to the hippocampal formation.
granule cell
A small, granular cell; those found in the dentate gyrus send axons to the field CA3 of the hippocampus.
Population EPSP
An evoked potential that represents the EPSPs of a population of neurons
perforant path
The system of axons that travel from cells in the entorhinal cortex to the dentate gyrus of the hippocampal formation.
associative long-term potentiation
A long-term potentiation in which concurrent stimulation of weak and strong synapses to a given neuron strengthens the weak ones.
NMDA receptor
A specialized ionotropic glutamate receptor that controls a calcium channel that is normally blocked by Mg2+ ions; involved in long-term potentiation.
AP5 2-Amino-5-phosphonopentanoate
A drug that blocks NMDA receptors.
dendritic spike
An action potential that occurs in the dendrite of some types of pyramidal cells.
AMPA receptor
An ionotropic glutamate receptor that controls a sodium channel; when open, it produces EPSPs.
CaM-KII
Type II calcium-calmodulin kinase, an enzyme that must be activated by calcium; may play a role in the establishment of long-term potentiation.
Nitric Oxide
is produced postsynaptically, but diffuses into presynaptic cell (retroactive messenger)
This promotes production of cyclic GMP, a second messenger
Long term LTP
There are two types, LTP2 and LTP3
LTP2 involves local protein synthesis, via messenger RNA’s that code for enzymes, receptor components, and structural proteins
LTP3 involves nuclear mRNA that is then transported out to dendrites
Proteins diffuse through cell protoplasm but are attracted by chemical “tags” on the dendritic spines where LTP1 and LTP2 have taken place
Instrumental conditioning
A form of learning related to the consequences of action. Formally described by B.F. Skinner. Outcomes either increase (reinforce) or decrease (punish) the probability of the behavior; also called operant conditioning.
Positive reinforcer
An appetitive stimulus that follows an instrumental behavior and thus makes the behavior become more frequent.
Negative reinforcer
An aversive stimulus whose occurrence is turned off by an instrumental behaviour, and thus makes the behaviour more frequent.
Punishing stimulus
An aversive stimulus that follows a particular behavior and thus makes the behavior become less frequent.
