Delayed suppression of recurrent excitation in the frog tectum column by endogenous acetylcholine

Abstract

Neuromodulator acetylcholine participates in the control of the activity of neuronal networks. The results of the present study have demonstrated that endogenous acetylcholine, released in the frog tectum column as a co-mediator, causes the delayed inhibition of the recurrent excitatory synaptic transmission in the tectum column. The delay of inhibition was estimated to be of ~80 ms, and the magnitude – more than 2 times. Suppression of the recurrent excitation enables a transition of the tectum column back to its lower activity level, suggesting a functional significance of the delayed inhibition: to establish the necessary conditions for returning of a neuronal network back to its resting state.