Neural- and endocrine control of flight XXXX in the adult cricket, Gryllus bimaculatus.

@entity12644 @entity121 @entity528
Neural- and endocrine mechanisms controlling @entity528 of a dorsal longitudinal flight muscle, M112a, have been studied in adult Gryllus bimaculatus (Orthoptera: Gryllidae). @entity12644 completely prevented @entity121 . Implantation of a pair of corpora allata or injection of juvenile hormone III into decapitated crickets caused @entity121 . Denervation of M112a resulted in reduction of muscle mass compared with that in sham-operated crickets. Denervation of M112a in decapitated crickets, however, did not affect muscle mass. Birefringence and ultrastructure of M112a showed an obvious regional difference in the onset of @entity528 . Fibrillar structures of M112a always disappeared from the ventral to dorsal part. Distribution of axon terminals of motor neurons and mechanical responses to the motor nerve stimuli showed that M112a is composed of five motor units with similar twitch properties. When M112a was fully denervated, regional differences in @entity528 disappeared. Partial denervation resulted in denervated muscle fibers losing birefringence earlier than innervated fibers. These results suggest that juvenile hormone causes breakdown of flight muscles, and neural factors control @entity528 of flight muscles to some extent under the presence of the juvenile hormone.
