Centrally Generated Nerve Impulse Sequences determining Swimming Behaviour in Tritonia

Abstract

AN act of behaviour is caused by correlated sequences of motor nerve impulses. These can be determined by pro-prioceptive input (reflexes), by strictly centrally generated programmes, or by a combination of the two. Much earlier work, particularly that on vertebrates^1–3, supported the view that continuing sensory input exclusively determines output patterns. This view was not readily compatible with several observations made by ethologists, for example on “fixed action patterns” released by “sign stimuli”, and a search was begun for centrally generated neural patterns. Experimental evidence suggesting such programmes is being found, particularly in invertebrates which have relatively simple nervous systems^4–7.