Protein Synthesis in Presynaptic Endings of Squid Brain: Regulation by Ca2+ Ions
It is generally accepted that long-term synaptic plasticity induced by electrophysiological or behavioral stimulation requires the modulation of gene expression, eventually leading to modification of the set of synaptic proteins (Montarolo et al., 1986; Otani et al., 1989). These changes are believed to occur in presynaptic and postsynaptic sites (dendrites) of the neuron. The ability of dendrites to synthesize proteins, is largely accepted (Rao & Steward, 1991). On the other hand, the concept of protein synthesis in presynaptic terminals is still controversial. This possibility was considered in the past (Austin et al., 1967; Morgan & Austin, 1968; Gordon & Deanin, 1968; Bridgers et al., 1971; Cotman & Taylor, 1971), but failed to achieve acceptance as the protein synthetic activity of synaptosomal fractions could be attributed to contaminating fragments of glial cells or dendrites, rather than to nerve endings.
KeywordsProtein Synthesis Optic Lobe Orotic Acid Calcium Ionophore A23187 Retinal Photoreceptor
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