EXPERIMENTALLY INDUCED RELEASE OF NEUROSECRETORY MATERIALS FROM ROACH CORPORA CARDIACA

Abstract

Neurosecretory materials within the corpora cardiaca of adult female roaches (Blaberus craniifer) were studied histologically, using chrome hematoxylin and phloxine or aldehyde fuchsin stains. Both the neurosecretory substances which are stained dark blue with chrome hematoxylin and those stained pink by phloxine are markedly depleted " in the corpora cardiaca following administration of electric shocks for periods of 15 minutes or more to the heads or abdomens of the roaches. Forced hyperactivity of the roaches, when continued for periods of 15 minutes or longer, also causes a marked decrease in the same neurosecretory materials within the corpora cardiaca. Following periods of forced hyperactivity of the animals, there is also a loss of the potency of extracts prepared from their corpora cardiaca, when such extracts are assayed for their ability to depress spontaneous activity in roach central nerve cords in vitro. It is suggested that the release of neurosecretory substances from the corpora cardiaca may be a part of the roach''s response to stress situations. Hyperactivity of the roaches and, to a lesser extent, electric shock treatments, result in the invasion of all parts of the brain by blood cells. The significance of this phenomenon is not known.