ACTIVATION OF MAUTHNER NEURONS DURING PREY CAPTURE

The Mauthner (M-) cells, a bilateral pair of medullary neurons in fish , initiate the characteristic ''C-start'' predatory escape response of teleosts. Similar movements have been described during hatching, soci al interactions, and feeding. M-cell firing, however, has not been cor related directly with these other behaviors. The objective of this stu dy was to determine whether the M-cell, in addition to escape, plays a role in feeding. 1. Goldfish were chronically implanted with electrod es positioned near the axon cap of one of the two M-cells. Subsequentl y, M-cell activity was monitored for up to 8 days while fish were surf ace feeding on live crickets. 2. The M-cell fires and the fish perform s a C-shaped flexion in association with the terminal phase of prey ca pture. Thus, the M-cell is active in the context of at least two behav iors, predator escape and prey capture, and may be considered a part o f behaviorally shared neural circuitry. 3. For the goldfish, Mauthner- initiated flexions during feeding rapidly remove the prey from the wat er's surface and minimizes the fish's own susceptibility to surface pr edation. Other species may possess a diverse repertoire of Mauthner-me diated feeding behaviors that depend on their adaptive specializations for predation. Moreover, group competition between predators and thei r prey may have facilitated a '' neural arms race for M-cell morpholog y and physiology.