D.N. LAPSHIN, M.V. FYODOROVA

THE FUNCTIONS OF THE B-CELL IN THE TYMPANIC ORGANS OF NOCTURNAL MOTHS (LEPIDOPTERA: NOCTUOIDEA)

The B-cell is a large unipolar neuron that belongs to the receptor complex in the tympanal organ of Noctuoidea moths. The responses of this neuron to the mechanical stimulation of thorax were investigated. Recording of it's electrical activity was carried out from tympanal nerve using tungsten electrode. In conditions of acute experiments the B-cell did not react to the acoustic stimuli, but mechanical pushing of some points of thorax caused either increase of average spiking frequency of this neuron (in moths Crino satura: Noctuidae) or phasic response timed to fronts of fast changes of stimulus (in Arctia caja: Arctiidae). Artificially evoked tymbal clicks of arctiids caused 2-3 spikes of the B cell with a latency of 3-6 ms. Responses of the most sensitive acoustic receptor cell A1 on such stimuli was reduced in comparison with it's reactions to external sounds. In view of morphological peculiarities of the cells B and A1 it is supposed that the B-cell is a receptor of own clicks in acoustically active nocturnal moths.

Crino satura Schiff.	Arctia caja L.	Diagram of the tympanal organ	The distribution of spontaneous activity of the B-cell

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The response of the B-cell to mechanical stimulation (C.satura)	The response of the B-cell to mechanical stimulation (A.caja)	Electric activity in the tympanal nerve	After-stimulus distribution of responses of the cells А1 and В
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