Neural Circuits

Abstract

In the decade that followed the first modern demonstrations of neural central pattern generators, scientific milestones achieved by Hughes and Wiersma (1960) and D.M. Wilson (1961), many groups attempted to understand the mechanisms that generated particular motor patterns by analyzing the patterns themselves and by perturbing the nervous system in different ways. These were classic input-output analyses, whose main virtue was that they could be done and whose main weakness was that they could not distinguish between the host of alternative equivalent neural mechanisms that could generate the observed motor patterns. In that context, positive results from antidromic stimulation experiments (e.g., Mulloney 1970, Stein 1971) were exciting because they eliminated a class of alternative models. From the frustration that grew among students and scientists who tried to analyze neural mechanisms with the methods then available grew the idea that if the synaptic organization of the neurons involved could somehow be discovered, the mechanism that generated these enticing motor patterns could be explained and understood. D.M. Maynard’s (1972) reports of the properties of the STG in various crustaceans were exciting because here was a nontrivial motor pattern generated by neurons from which we could record more than impulses. Perhaps this ganglion generated behaviors that physiologists could understand.