NRSC 4032 Chapter Notes - Chapter 2: Aplysia Gill And Siphon Withdrawal Reflex, Schaffer Collateral, Dentate Gyrus
Document Summary
Karl lashley (1950) made first serious attempt to locate the memory trace. When the siphon is touched multiple times the rate of the reaction decreases because of habituation: habituation- the magnitude of the response decreases with repeated stimulation. Spontaneous recovery- with the passage of time between stimulus, the response to that stimulus can recover. The circuit could be studies and eventually the synapses could be studied as well. Long term potentiation: a potentiated response to the weak test stimulus: happens in the hippocampus, the hippocampus is essential for episodic memory, hippocampus- contain modifiable synapses that can maintain complex circuits of memory traces. Entorhinal cortex --perforant path--> dentate gyrus--mossy fibers--> ca3 pyramidal cells-- Schaffer collateral fibers-->ca1: ca1 and ca3 contain pyramidal cells, ltp- strong stimulus potentiates the response to the weak stimulus. If we stimulate perforant path, we measure granule cells. This is because the extracellular electrode is being filled with sodium (making it more negative).
