Question

what types of structural changes may occur in the membranes of individual neurons and in the natural circuitry of the hippocampus as a result of LTP?

explain please

Answer 1

Long-term potentiation(LTP), is an increase in synaptic response following potentiating pulses of electrical stimuli that sustains at a level above the baseline response for hours or longer. LTP involves interactions between postsynaptic neurons and the specific presynaptic inputs that form a synaptic association, and is specific to the stimulated pathway of synaptic transmission. The long-term stabilization of synaptic changes is determined by a parallel increase of pre- and postsynaptic structures such as axonal bouton, dendritic spine and postsynaptic density.On the molecular level, an increase of the postsynaptic scaffolding proteins PSD-95 and Homer1c has been shown to correlate with the stabilization of synaptic enlargement.

Modification of astrocyte coverage at the synapses in the hippocampus has been found to result from the induction of LTP, which has been found to be linked to the release of D-serine, nitric oxide, and the chemokine by astrocytes. LTP is also a model for studying the synaptic plasticity. Induction conditions resemble those described for the initiation of long-term depression, but a stronger depolarization and a greater increase of calcium are necessary to achieve LTP.

LTP induced at the CA3–CA1 hippocampal synapses employing high-frequency stimulation or TBS is dependent on the NMDA receptor. Induction of LTP at CA3–CA1 hippocampal synapses leads to persistent augmentation of dendritic summation of two Schaffer-collateral inputs and summation occurs only at the potentiated input.