Hyppocampus en LTP

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19-01-2009 14:26:40

is er iemand die mij eens kan uitleggen wat LTP is en wat of waar de link ligt met de hyppocampus?


19-01-2009 14:55:31

LTP was first observed by Terje LÝmo in 1966 in the Oslo, Norway, laboratory of Per Andersen.[8] There, LÝmo conducted a series of neurophysiological experiments on anesthetized rabbits to explore the role of the hippocampus in short-term memory.

Isolating the connections between two parts of the hippocampus, the perforant pathway and dentate gyrus, LÝmo observed the electrical changes in the dentate gyrus that were caused by stimulation of the perforant pathway. As expected, a single pulse of electrical stimulation to a fiber of the perforant pathway, the presynaptic fiber, caused an excitatory postsynaptic potential (EPSP) in a cell of the dentate gyrus, the postsynaptic cell. What LÝmo did not expect was that the postsynaptic cell's response to these single-pulse stimuli could be enhanced for a long period of time if he first delivered a high-frequency train of stimuli to the presynaptic fiber. When such a train of stimuli was applied, subsequent single-pulse stimuli elicited stronger, prolonged EPSPs in the postsynaptic cell. This phenomenon, whereby a high-frequency stimulus could produce a long-lived enhancement in the postsynaptic cell's response to subsequent single-pulse stimuli, was initially called "long-lasting potentiation".[9][10]