LONG-TERM POTENTIATION AND SYNAPTIC PROTEIN-PHOSPHORYLATION

Long-term potentiation (LTP) is a well known experimental model for st udying the activity-dependent enhancement of synaptic plasticity, and because of its long duration and its associative properties, it has be en proposed as a system to investigate the molecular mechanisms of mem ory formation. At present, there are several lines of evidence that in dicate that pre- and postsynaptic kinases and their specific substrate s are involved in molecular mechanisms underlying LTP. Many studies fo cus on the involvement of protein kinase C (PKC). One way to investiga te the role of PKC in long-term potentiation is to determine the degre e of phosphorylation of its substrates after in situ phosphorylation i n hippocampal slices. Two possible targets are the presynaptic membran e-associated protein B-50 (a.k.a. GAP 43, neuromodulin and F1), which has been implicated in different forms of synaptical plasticity in the brain such as neurite outgrowth, hippocampal LTP and neurotransmitter release, and the postsynaptic protein neurogranin (a.k.a. RC3, BICKS and p17) which function remains to be determined. This review will foc us on the protein kinase C activity in pre- and postsynaptic compartme nt during the early phase of LTP and the possible involvement of its s ubstrates B-50 and neurogranin.