The neuronal basis of behavior in Tritonia. IV. The central origin of a fixed action pattern demonstrated in the isolated brain

Publisher Website
Google Scholar
Abstract
The mechanisms which initiate and integrate the patterned sequence of activity in the interacting cell groups responsible for the swimming behavior of Tritonia remain operative after complete isolation of the brain from the periphery. Following isolation, a short electrical stimulus applied to a nerve from the oral veil leads to patterned bursting in the flexion neurons of the pedal ganglia, which is identical to that occurring in the same cells during the swimming escape response.Direct evidence of cell‐cell interaction in the form of unitary postsynaptic potentials was not obtained, but the close synchronization of burst patterning in both ipsilateral and contralateral synergists infers the existence of positive feed back between many neurons of the group. Alternating bursts of impulses in functional antagonists are associated with reciprocal inhibition between the two networks. As all possibility of proprioceptive feedback has been excluded in the isolated brain, it is evident that the motor output pattern for the escape‐swimming response has been generated by a central mechanism without reference to sensory input, which serves only to trigger the action.