learning, synaptic plasticity and memory Flashcards
what is neural plasticity?
and what can it be observed as?
changes that are caused by previous experience
- behaviour
- neurons
- synapses
what is learning?
process of acquiring new info
what is memory?
ability to store and retrieve new info
what are the 3 types of learning and examples?
non-associative (sensitisation and habituation)
associative (classical conditioning and structural changes in hippocampus with spatial learning)
imprinting
what is nondecelarative memory?
LTM procedural - skill learning - conditioning doesn't require conscious recall
what is declarative learning?
LTM
semantic - knowledge of facts
episodic - what happened
requires conscious recall
what are intermediate-term memory?
outlast short term memory but not permanent
e.g yesterday lunch
what is meant by encoding and consolidation?
sensory buffers are encoded to stay in STM
STMs are consolidated to stay in LTM
who determined that memory isn’t localised and how?
Lashley
rats studied with lesions
how to change the efficiency of a neuron?
temporal filtering (change in frequency range of spikes)
gain control (change amount of neurotransmitters)
presynaptic facilitation or depression
what are some synaptic changes that can occur after training that lead to a stronger signal?
more neurotransmitter
membrane size/sensitivity
pre and post synaptic size
lead to stronger signal
what is habituation?
response weakens with repeated stimulus presentation due to repitition
not due to adaptation or fatigue
what is dishabituation?
normal response reinstated when stimulated by a different stimulus
what is LTM formation characterised by?
structural changes in neurons
what is sensitisation?
response much stronger when pain inflicted beforehand
what do hippocampal lesions impair?
spatial task
not working or reference memory
what are the 3 main pathways of teh hippocampus?
- perforant pathway
- mossy fibre pathway
- schaffer collateral pathway
what is long term potentiation (LTP)?
a stable and enduring increase in the effectiveness of synapses following repeated stimulations
can occur at several sites in the hippocampal formation
what are AMPA receptors?
ionotropic receptors
open if glutamate binds to them and Na+ flows into postsynaptic neuron (depolarises membrane)
what are NMDA receptors?
critical in formation of LTP:
both ligand and voltage gated
open when bind with glutamate and membrane depolarises above threshold expelling Mg2+ plug
leads to influx of Ca2+ in postsynaptic cell which contributes to excitatory potential
why is the NMDA receptor a substrate for associative learning?
critical in formation of LTP:
found in neuronal pathways required for associative learning
activated when 2 events happen together
what does CREB target?
many genes that are required for growing new dendritic spines and synapses
