Intracellular Recordings of Neck Muscle Motoneurones During Eye Cleaning Behaviour of the Cricket

Intracellular recordings were made from prothoracic neurones of crickets which were free to move in a quite normal way. During the head roll component of eye cleaning, the motoneurones (MNs) to the driving muscles, dorso-ventral neck muscles 55, 56 and 60, received excitatory and/or inhibitory input from several spiking neurones. The discharge patterns of these MNs were basically identical to those in intact animals. Lesion of connectives showed that the motor pattern of eye cleaning is generated by a complex neural network in the prothoracic and the suboesophageal ganglia, in which both neck connectives are involved. Single electric shocks to the axons of the interommatidial mechanoreceptors through which eye cleaning is elicited evoked an EPSP followed by an IPSP with a latency of about 10 ms in all MNs of the three muscles on both sides. During repeated stimulation of the receptors this input is predominantly inhibitory.