Structural and functional characterisation of some insect central neurones

Abstract

Histological studies of the distribution of cell bodies within the metathoracic ganglion of both the stick insect Carausius morosus and the cricket Gryllus bimaculatus were carried out using orthodox histological techniques (silver, iron haematoxylin ) as well as back-filling and intracellular injection staining techniques with both Cobalt Chloride and Procion yellow as well as whole mount staining techniques. Maps of geographical groups of cell bodies of the metathoracic ganglion of both insects were reconstructed from serial sections. Salient through-tracts were described. Neurones that innervate the dorsal longitudinal flight muscles were identified in both the mesothoracic and metathoracic ganglia of Gryllus bimaculatus, and their detailed morphological properties were described. Difficulties imposed by resistance of the neural sheath to impaling glass microelectrodes and by some of the substances used were discussed. Neurophysiological and pharmacological experiments were carried out to identify some of the physiological properties of the neurones that innervate the dorsal longitudinal flight muscles of the cricket, Gryllus bimaculatus.