Free and bound cyclic AMP in the brain of the moth Mamestra configurata Wlk. during pupal–adult metamorphosis

Abstract

Neither free nor bound cyclic AMP in the brain of the moth Mamestra configurata changed significantly during the first few days in which neuroendocrine events responsible for initiating pupal–adult development occurred. Apparently, the level of bound cyclic AMP in the brain reflects a state of protein kinase activation that is sufficient to initiate development in pupae that have completed diapause and are exposed to temperatures above the initiation threshold. Brain cyclic AMP is not involved in the transduction of photoperiodic signals in the pupa of M. configurata, as it is in the pupa of certain silkmoths.Large increases occur in the level of free and bound cyclic AMP in the brain of M. configurata after neuroendocrine events have initiated development, indicating that cyclic AMP acting via a cyclic AMP-dependent protein kinase may participate in brain differentiation. The high level of free and bound cyclic AMP in the adult brain may be related to an increased number of synapses and (or) the magnitude of synaptic activity and is in keeping with the increased activity of the cholinergic and octopaminergic systems also observed during brain ontogeny in lepidopterans.