Daily changes in synthesis and accumulation of neurosecretion in the brain of the house crickets

Abstract

Abstract The experiments were carried out on the house crickets, Acheta domesticus L. reared in LD 12:12 photoperiod at 28°C. The levels of neurosecretion synthesis were studied by means of autoradiography using 35S‐cysteine as a precursor for the neurosecretory proteins. It was found that maximal incorporation of 35S‐cysteine by the neurosecretory cells of pars intercerebralis of the brain occurs during the light period at about midday, that is during the low locomotor activity of the investigated insects. During the same period, staining of neurosecretory cells with paraldehyde fuchsin indicated a relatively small accumulation of neurosecretion. During the dark period, when the crickets are very active, the incorporation of 35S‐cysteine by the neurosecretory cells of the brain is at its lowest level and the degree of accumulation of neurosecretion reaches its highest value.