Mutual coupling among insect neurosecretory cells with an ultradian firing rhythm

Abstract

Firing correlations were examined among four pairs of cerebral neurosecretory cells with an ultradian bursting rhythm in the pupal silkmoth Bombyx mori. Cross-correlation analyses of spiking activities between pairs of simultaneously active cells usually revealed a significant correlation of firings: 20–50% of spikes of a cell fired within 0.2 s before or after the other cell's spikes fired. The mutual, excitatory communication among neurosecretory cells make the set of cells a weakly coupled multi-oscillator system that may generates a pulsatile release pattern of their product, an insulin-related neuropeptide (bombyxin).