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Lecture 24. Learning and Memory II. Memories. Long term memory stored in cortex Information is processed for memory storage in other brain regions (i.e hippocampus). Long-term Potentiation. Timothy Bliss and Terje Lomo (1973)
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Lecture 24 Learning and Memory II
Memories • Long term memory stored in cortex • Information is processed for memory storage in other brain regions (i.e hippocampus)
Long-term Potentiation • Timothy Bliss and Terje Lomo (1973) • Facilitation of synaptic transmission following high-frequency electrical stimulation applied to presynaptic neurons
Evidence for LTP and learning and memory • LTP can last for a long time • LTP is dependent on presynaptic and postsynaptic neurons firing • LTP can be elicited by stimulation that mimics neural activity • LTP is demonstrated in hippocampus and other areas that have been implicated in learning and memory • Behavioral conditioning can produce LTP-like changes (aplysia experiments)
Evidence for LTP and learning and memory • Drugs that influence learning, influence LTP • Maximal LTP blocks learning, normal LTP promotes learning and memory • Mutant mice that display no LTP don’t learn well • LTP occurs at synapses that have been shown to be involved in learning and memory
Protein kinases involved in LTP • Protein kinase A (PKA) • Protein kinase C (PKC) • Calcium-calmodulin kinase (CaM Kinase or CaMK) • Tyrosine kinase (TK)
Stages of memories • Iconic • Short-term • Intermediate term • Long term
Hypotheses for memory decline • Disease (Alzheimer’s) • Loss of neurons and/or neural connections • Impairment of the cholinergic system • Impaired coding by place cells
Preventing memory decline…? • Lower glucocorticoids • Infusion of NGF into the brain…? • Live an enriched lifestyle