Neuromelanin: a hypothetical component of bioelectronic mechanisms in brain function.

Several lines of evidence suggest the involvement of bioelectronic mechanisms in brain function. Although no components of such mechanisms have been identified, neuromelanin is a likely candidate. The functional significance of neuromelanin is supported by considerable published work, herein reviewed. Certain electronic properties of melanin, notably in stable free radical characteristics and its semiconduction, may be influenced by alpha-MSH, ACTH 4-10, and melatonin. Neuron function may be influenced in turn by the effect of semiconduction on synaptic transmission. Thus neuromelanin may be an important part of a complex neural modulation system.