抄録
The effect of Pentylenetetrazol (PTZ, Metrazol) upon the identified neurons of Japanese land snail was studied.
1) In the pleuro-parieto-visceral ganglion of Japanese land snail, Euhadra peliomphala, three types of cells can be differentiated morphologically and functionally as those; depolarized by acetylcholine (D-cell), hyperpolarized by acetylcholine (H-cell) and indifferent to acetylcholine (I-cell).
2) PTZ produces a phasic depolarization followed by a sustained depolarization in the D- and H-cells.
3) PTZ has no specific effect upon the I-cell.
4) By application of d-tubocurarine, atropine and hexamethonium, the typical phasic activity evoked by PTZ is not affected in either the D- or H-cells, suggesting that the effect of PTZ is not of synaptic origin but of endogeneous origin.
5) Neither cholinergic nor noncholinergic inhibitory input to the Dand H-cells are affected even at the peak of PTZ activity.
