Action of epinephrine and related compounds upon the insect nervous system

Abstract

Epinephrine, nor-epinephrine, and dopamine produce a variety of neurological effects in the cockroach. These effects include increased activity in the central nervous system and facilitation, then block, of cercal nerve-giant fiber synapses. The same compounds produce behavioral effects including antennal tremors, altered coordination, and egg-laying behavior in females. The molecular structure essential for maximal neurophysiological or behavioral effects consists of a benzene ring, with two hydroxyl groups in meta and para positions, plus the alkylamine side chain of epinephrine. Epinephrine mimics some, but not all, of the neurophysiological effects of corpus cardiacum extracts. Thus the neurological actions of such extracts cannot be ascribed to epinephrine or epinephrinelike compounds alone. Both neurological and behavioral responses to epinephrine are temporarily absent for periods of 3–15 days following molting, prolonged hyperactivity, and stresslike conditions.