Mechanisms of synaptic modulation.

Publisher Summary This chapter discusses the mechanism of synaptic modulation. Synaptic modulation is an observed change in the synaptic function. This change can occur by summation of a variety of physiological and biochemical cellular responses. Thus, the term, “synaptic modulation” does not make a precise statement and in this sense, is not analogous to the term, “synaptic transmission.” Synaptic transmission describes the transfer of a signal from one cell to another using mechanisms that are similar at all synapses. Synaptic transmission occurs at a particular location that can be described by morphologically pre- and postsynaptic specializations, which involves vesicular release of a neurotransmitter, and elicits a response from the postsynaptic cell through receptors that recognize the specific transmitter released. There are data inconsistent with this description, that is, release of amino acid transmitters that may not be vesicular, and adrenergic synapses that are difficult to describe morphologically. However, the term, “synaptic transmission” conveys both the description of the event as well as the mechanism involved.