A fluorescence histochemical technique with glyoxylic acid has been employed to locate the catecholamines noradrenalin and dopamine and the indolealkylamine 5-hydroxytryptamine (5HT) in the brains of a number of genera of cephalopods. The slow-fading green fluorescence typical of noradrenalin and dopamine was located in the neuropil of most lobes and in some of the cell bodies of the superior and posterior buccal lobes, the median basal, magnocellular and vasomotor lobes. Fast-fading fluorescence typical of 5HT was associated with green fluorescence in the neuropil of the peduncle, anterior basal, olfactory, subpedunculate, subvertical, precommissural, superior buccal, optic, pedal and brachial lobes. Only the optic gland displayed yellow fluorescence alone. Photographic evidence is presented to emphasize that in the cephalopod brain the fluorescence is not uniformly distributed. The possibility that noradrenalin, dopamine and 5HT have specific neurotransmitter functions is discussed.
Power-control problems caused by fast fading in a direct-sequence multiple-access network
