Centralgenic motoneuron bursts accompanying various gill plate movements in Limulus polyphemus (Linnaeus)

Abstract

1. 1. Motoneuron bursts, which underly ventilatory, hyperventilatory and swimming muscle activity in intact animals, can be generated by the isolated CNS of Limulus without proprioceptive feedback. 2. 2. Ventilatory motoneuron bursts involve low frequency firing of a small number of different sized spikes. During hyperventilation, several larger spikes become active, and the firing frequency of the smaller spikes increases. Swimming bursts include large and small spikes all firing at high frequencies. 3. 3. Longitudinal bisection of the opisthosomal ganglia causes desynchronization of the ventilatory motoneuron bursts from contralateral hemiganglia, while swimming bursts remain normally synchronized.