BMS11004 - WEEK 6 THURSDAY Flashcards
outline engram
physical embodiment of memory
define procedural memory
skills and associations largely unavailable to conscious mind
define declarative memory
available to conscious mind and can be encoded in symbols and language
define explicit memory
memories consciously recalled, eg: riding bike
define implicit memory
not consciously recalled, eg; learning to ride bike
what does electrical stimulation of temporal lobe cause
hallucinations, recollection of past experiences
what is prefrontal cortex responsible for
WM
what is hippocampus responsible for
converting STM-LTM, decalrative
lesioning cause memory loss
3 layers, enlarged in those with good spatial memories
what is amygdala responsible for
processes sensory input, involved in implicit/emotional/learnt fear
what is cerebellum responsible for
procedural and sensorimotor memories
what is reverberating circuits
when forming memory, a specific population of neurons constantly fire in certain direction
what is hebbian synapse
synapses inbetween neurons change during memory formation “plastic synapse”
describe increase or decrease in synaptic strength
facilitation/depression
what is long-term facilitation/depressions due to
requires gene expression of specific gene by neurons changing NT released into synapse which changes duration of which synaptic strength change can occur
define long term potentiation
long lasting enhancement of effectiveness of synaptic transmission following certain types of conditioning stimulation
how can you measure long term potentiation
hippocampal slice, neuronal recordings between neurons CA3 and CA1
CA3: pre synapse neuron, fire EPSPs
CA1: post synapse neuron, tetanic long term potentiation
in paired long- term potentiation, what occurs at what can this suggest
depolarises both neuron at same time, suggesting can be basis of associative learning (classical conditioning)
explain research origins in memory on snail reflex
touch near siphon = gill withdrawal
habituation to touching siphon cause reduced gill withdrawals
pair single tail pinch (aversive) with siphon touch re-establish siphon reflexes
explain long-term sensitisation with siphons and snail
repeated pairing of siphon touch and tail pinch (long-term, non-habituating siphon + gill reflex)
what does long term potentiation require (messengers, NT)
receptor activation for glutamate, serotonin
alter synaptic responsivity
mediated by 2nd messenger (eg; cAMP)
require protein phosphorylation changes in early stages
require protein synthesis for late stages
involve biochemical and structural pre and post-synaptic changes
how does long-term potentiation occur
postt-synaptic event = Ca enter post-syn, trigger LTP, trafficking of AMPA receptors to post-synaptic membrane, cause change to synaptic strength, depolarise post-synaptic neuron
activates NMDA receptor, through chemical cascade reactions, activates kinase which phosphoylate AMPA receptor, increase trafficking of AMPA receptor onto membrane
