Faculty Collaboration Database

Giant multimodal heart motoneurons of Achatina fulica: a new cardioregulatory input in pulmonates. Comp Biochem Physiol A Mol Integr Physiol 2001 Aug;130(1):183-96

Date

10/24/2001

Pubmed ID

11672694

DOI

10.1016/s1095-6433(01)00384-1

Scopus ID

2-s2.0-0034902069 (requires institutional sign-in at Scopus site)   18 Citations

Abstract

The regulation of the heartbeat by the two largest neurons, d-VLN and d-RPLN, on the dorsal surface of visceral and right parietal ganglia of Giant African snail, Achatina fulica, was examined. Using the new method of animal preparation, for the first time, discrete biphasic inhibitory-excitatory junction potentials (I-EJPs) in the heart and several muscles of the visceral sac were recorded. The duration of hyperpolarizing phase (H-phase) of biphasic I-EJPs was 269+/-5.6 ms (n=5), which is 2-3 times less than that of the cholinergic inhibitory JPs (682+/-68.5 ms, n=5). The H-phase of I-EJPs was not altered by the application of atropine, picrotoxine, succinylcholinchloride, D-tubocurarine and tetraethylammonium or substitution of Cl(-) ions. Even the low-frequency neuronal discharges (1-2 imp/s) evoked significant facilitation and potentiation of the H-phase. Between the multimodal neurons d-VLN/d-RPLN and mantle or visceral organs there is evidence of direct synaptic connections. These neurons were found to have no axonal branches in the intestinal nerve as once suspected but reach the heart through several other nerves. New giant heart motoneurons do not interact with previously identified cardioregulatory neurons.

Author List

Zhuravlev V, Bugaj V, Kodirov S, Safonova T, Staruschenko A

MESH terms used to index this publication - Major topics in bold

Animals
Atropine
Convulsants
Electric Stimulation
Electrophysiology
Heart
Membrane Potentials
Motor Neurons
Myocardial Contraction
Neuromuscular Depolarizing Agents
Parasympatholytics
Picrotoxin
Potassium Channel Blockers
Snails
Succinylcholine
Tetraethylammonium
Tubocurarine