Phasic nicotinic potentiation of frog retinotectal transmission facilitates eliciting of higher activity level of the tectum column

Abstract

Nicotinic acetylcholine receptors contribute to the mediation of cholinergic role in attention, vigilance, orienting and detection of behavioral significant stimuli. We have recently demonstrated an increase of the intrinsic recurrent excitatory activity of the tectum column caused by the phasic (after-burst) nicotinic potentiation of a frog single axon retinotectal transmission to the tectum layer F. We have shown in the present study that the phasic nicotinic potentiation facilitates eliciting of higher activity level of the tectum column featured by generation of output signals from the tectum column. Since these signals can lead to an escape from danger reactions, a functional significance of nicotinic modulation of the neural network has been demonstrated. The phasic nicotinic potentiation that facilitates eliciting of higher activity level of the tectum column can be considered as a mechanism of vigilance and cue detection at the level of small neural network.

Keywords: A(fSP); A(fSP,pot); A(sNP); A(sNW); AP; Art; Efferent neuron firing; Frog tectum column; N; Neural network; Presynaptic nicotinic potentiation; T(sNP); Vigilance; amplitude of the control fSP; amplitude of the potentiated fSP; amplitude of the sNP; difference of number of pulses between weakest stimuli that evoked the sNP in unpotentiated (control) and potentiated cases; duration of the sNP; fSP; individual retinotectal action potential; individual retinotectal fast synaptic potential; magnitude of the sNW; number of pulses in stimulus; sNP; sNW; slow negative potential; slow negative wave; stimulus artifact; ΔN.