neurochemistry and memory (powerpoint #5) – Flashcards

1. docking:you are in the vicinity (need calcium for this step to move the vesicles from the reserve pool to the docking station) 2.priming:linking you up to the dock, aligned perfectly 3.fusion:fusion core is open and vesicle merging with the postsynaptic membrane (calcium needed) 4.release:

-each neurotransmitter has several different receptors it can bind to -specific activity it has on the post synaptic neurons depends on the type of receptor it binds to

-GABA is almost always inhibitory , IPSP: flow of chloride -Glutamate almost always excitatory , EPSP: flow of sodium

1. ionotropic: movements of ions, opening of ion channel , influx of either sodium or chloride and resulting EPSP or IPSP (direct, fast, short-acting) -mix and match subunits which can affect how long the channels stay open, how many open, how many NTs are needed to open the channel, etc 2.Metabotropic: engage in signaling through second messengers.neurotransmitter binds and changes shape of receptors and causes a change in the cell, and leads to a cascade of events, end result is a variety of things. slow but long lasting -protein usually, cannot mix or match -effects depend on the associated G-protein AND the second messengers/effectors present in the cell

1. degradation:after the neurotransmitter is released, an enzyme breaks down the transmitters in the synapse into a form where it does not signal. then it is taken up into the presynaptic membrane where another enzyme makes it ready for signaling again 2.reuptake:transporters are on the presynaptic membrane and they are pumps that are taking up specific neurotransmitters from the cleft ; then they are repackaged into vesicles and put in the reserve pool; so you can release the same neurotransmitters again and again -usually both happens, if reuptake doesn't get all the transmitters, the remaining are degraded in the synapse

1.Encoding: The process of creating a connection between neurons to store the memory 2.Consolidation: The process of moving a memory into long-term storage and/or integrating with other stored information 3.Retrieval: Bringing the stored memory back into the conscious awareness

Strengthening the neuron: 1)neurotransmitter signaling-> long term potentiation -if you keep stimulating a post synaptic neuron eventually the same stimulus will give you a bigger effect in that post synaptic neuron -caused by: 1) trafficking of additional receptors to the post synaptic membranes (glutamate receptors) leads to additional ion channels opening -2)retrograde signaling that occurs that leads to an increase in the number of vesicles that are fused to the membrane for a fusion event -> leads to an increase of sodium ions that can flow in -therefore the same action potential can lead to a more efficient and greater effect

-experience-dependent: will only become strengthened if you use it a lot -input specificity: only certain parts of the terminals are changed, in other words only the active pathway is potentiated (not all of the synapse is more sensitive)

if a weak neuron and a strong neuron are stimulated at the same time, the weak synapse will become strengthened

-also cellular mechanisms of learning -constantly sprouting new dendrites just to see if there's anything new (ongoing plasticity) -if there is a connection then this dendrite will be strengthened -if it isn't being used (rarely a stimulus for coactivation) then it will be prune that synapse so that there will be room/ resources for one that is more useful

-short term memory located in hippocampus, long -term usually in cortex -episodic memories (you make a personal association) still use the hippocampus after a few months unlike semantic memories; -in the episodic, posterior parts of the brain were more active months later while anterior was active only initially

-Retrieval is a reconstructive process -Can result from controlled search as well as spontaneous recovery -Lateral PFC regions involved in search, particularly right hemisphere -MTL involved in spontaneous memory recovery

-when you bring something up to working memory, if you change info as u are using it will get reconsolidated into its new state into long term memory -this is how memories get distorted(emotion, suggestion, filling in holes logically can all happen when you recall)