BASAL, DOPAMINE‐ AND OCTOPAMINE‐STIMULATED ADENYLATE CYCLASE ACTIVITY IN THE BRAIN OF THE MOTH, MAMESTRA CONFIGURATA, DURING ITS METAMORPHOSIS1

Abstract

Abstract—The specific activities of basal, dopamine‐ and octopamine‐stimulated adenylate cyclase in the brain of the moth, Mamestra configurata, increased by an order of magnitude or more during the transition from pupal to adult brain. Increases in adenylate cyclase activity outpaced increases in brain weight and protein content by a wide margin, especially during the last 10 days of metamorphosis when most of the change in enzyme activity occurred.The greatly enhanced adenylate cyclase activity appears to reflect increased demands placed on the adult brain as an integrative centre, especially in the integration of sensory input from the eyes and antennae. Growth of the optic lobes during brain development contributed a substantial proportion of basal (33%), dopamine‐sensitive (21%) and octopamine‐sensitive (37%) adenylate cyclase activity to the adult brain. High levels of octopamine and the presence of active octopamine‐sensitive adenylate cyclase suggest a cyclic AMP‐mediated physiological function for octopamine in the optic lobes of the insect brain, probably as a neurotransmitter or neuromodulator.