Intracellular activity in cricket neurons during the generation of behaviour patterns.

Abstract Intracellular recordings from interneurons and identified motor neurons were made in the mesothoracic ganglion of Gryllus campestris during the generation of the evasion response, the ventilatory rhythm, and the flight pattern. Responses were elicited by antennal or cercal stimulation after all peripheral nerves had been cut except those of the cercal and head ganglia. Neuron somata were not involved in integration. Central inhibition of motor neurons was employed in the control of behaviour patterns. Units were found whose activity corresponded to that expected of the inhibitors. During generation of the flight pattern, the intracellular potential of motor neurons underwent a smooth oscillation as a result of driving input; some of this input was from interneurons. Motor neurons innervating the same muscle were electrically coupled.