Limbic system and learning/memory Flashcards
Why did patient HM have memory deficits?
He had his hippocampus, perirhinal cortex, and amygdala removed
Declarative memory
ability to recollect events or facts that have a specific temporal and spatial context as well as semantic knowledge
Where is declarative memory formed and consolidated?
Hippocampus
Where is declarative memory stored?
Neocortex. Important in storage of faces
Procedural memory
ability to learn new motor skills
What structures process procedural memory?
cerebellum, striatum, frontal cortex
What area of brain is activated during face recognition tasks?
inferotemporal cortex
Short-term memory
memory lasting fractions of a second to seconds. Sensory systems –> sensory cortex
Working memory
Memory lasting from seconds to minutes. Dorsolateral prefrontal cortex
Lesion in dorsolateral prefrontal cortex
forgetting things like where you left your keys; executive dysfunction; confabulation
Long term memory
lasts days to years. Stored in neocortex
Input pathway to hippocampus
entorhinal cortex via perforant path –> dentate gyrus –> mossy fibers –> CA3 on Ammon’s horn –> Schaeffer collaterals –> CA1
Output from hippocampus
CA3 and CA1 –> fornix
How is LTP induced in hippocampus?
repeated stimulation of:
perforant path –> CA3
or
Schaeffer collaterals –> CA1
Molecular basis for LTP
simultaneous glutamate excitation and postsynaptic depolarization –> NMDA activation –> Ca influx –> Calmodulin stimulation –> CaM kinase II stimulation –> autophosphorylation of CaM Kinase II –> prolonged activity –> larger EPSP, incorporated and phosphorylated AMPA receptors –> increased glutamate response
