Identification of giant neurones in the dorsal surface of the suboesophageal ganglia of Japanese domestic snail ( Euhadra Congenita Hickonis Kobelt)

Abstract

1. The following giant neurones were identified in the dorsal surface of the suboesophageal ganglia of a Japanese domestic snail ( Euhadra congenita hickonis Kobelt): d-RPLE (dorsal-right parietal large Euhadra neurone), d-LPLE (dorsal-left parietal large Euhadra neurone), d-VCCSE (dorsal-visceral cerebro-pleural connective superior Euhadra neurone) and d-VCCIE (dorsal-visceral cerebro-pleural connective inferior Euhadra neurone). Their axonal pathways were observed by intracellular injection of Lucifer yellow; their sensitivities to the putative neurotransmitters and derivatives were studied. 2. d-RPLE and d-LPLE, situated in the rostral part of the ganglia, may correspond to d-RPLN (dorsal-right parietal large neurone) and d-VLN (dorsal-visceral large neurone) of Achatina fulica, but much differences in the pharmacological features were found between the neurones of the two species. We cannot point out any Achatina neurones which correspond to d-RPINE, d-VCCSE and d-VCCIE. 3. The amines and amino acids effective on the Euhadra neurones tested were comparable to those on the Achatina neurones; for example, the Euhadra neurones were insensitive to l-glutamic acid, but some of them were sensitive to β-hydroxy- l-glutamic acid. Likewise the case of Achatina neurones. The Euhadra neurones were insensitive to the peptides tested, though some Achatina neurones were sensitive to oxytocin and FMRFamide.