Connexin-36 gap junctions mediate electrical coupling between ventral tegmental area GABA neurons.

Details

Serval ID
serval:BIB_A5F439815EB8
Type
Article: article from journal or magazin.
Collection
Publications
Title
Connexin-36 gap junctions mediate electrical coupling between ventral tegmental area GABA neurons.
Journal
Synapse
Author(s)
Allison D.W., Ohran A.J., Stobbs S.H., Mameli M., Valenzuela C.F., Sudweeks S.N., Ray A.P., Henriksen S.J., Steffensen S.C.
ISSN
0887-4476 (Print)
ISSN-L
0887-4476
Publication state
Published
Issued date
07/2006
Peer-reviewed
Oui
Volume
60
Number
1
Pages
20-31
Language
english
Notes
Publication types: Journal Article ; Research Support, N.I.H., Extramural
Publication Status: ppublish
Abstract
Communication between neurons in the mammalian brain is primarily through chemical synapses; however, evidence is accumulating in support of electrical synaptic transmission between some neuronal types in the mature nervous system. The authors have recently demonstrated that the gap junction (GJ) blocker quinidine suppresses stimulus-induced and dopamine-evoked coupling of gamma amino butyric acid (GABA) neurons in the ventral tegmental area (VTA) of mature rats (Stobbs et al., 2004). The aim of this study was to evaluate the role of connexin-36 (Cx36) GJs in mediating electrical coupling between VTA GABA neurons in P50-80 rats in vivo and P25-50 rats in vitro. Single stimulation of the internal capsule (IC) evoked VTA GABA neuron spike couplets in mature rats when activated antidromically, and multiple poststimulus spike discharges (PSDs) when activated with brief high-frequency stimulation of the IC (ICPSDs). The Cx36 GJ blocker mefloquine (30 mg/kg) suppressed VTA GABA neuron ICPSDs in mature freely behaving rats. VTA GABA neurons recorded via whole-cell patch clamp in the midbrain slice preparation of P25-50 rats showed robust expression of Cx36 transcripts when tested with single-cell quantitative reverse transcription polymerase chain reaction. In P50-80 rats, Cx36 protein immunoreactivity was evident in the VTA and surrounding structures. Dye-coupling between VTA neurons was observed following Neurobiotin labeling of VTA GABA neurons, as well as with the fluorochrome Alexa Fluor 488 using real-time video fluorescent microscopy. Thus, mature VTA GABA neurons appear to be connected by electrical synapses via Cx36 GJs, whose coupling is enhanced by corticotegmental input and by dopamine.

Keywords
Animals, Antimalarials/pharmacology, Cell Communication/physiology, Connexins/drug effects, Connexins/metabolism, Electric Stimulation, Evoked Potentials/drug effects, Evoked Potentials/physiology, Gap Junctions/drug effects, Gap Junctions/metabolism, Male, Mefloquine/pharmacology, Neurons/drug effects, Neurons/metabolism, Patch-Clamp Techniques, Rats, Rats, Wistar, Reverse Transcriptase Polymerase Chain Reaction, Synaptic Transmission/physiology, Ventral Tegmental Area/drug effects, Ventral Tegmental Area/metabolism, gamma-Aminobutyric Acid/metabolism
Pubmed
Web of science
Create date
03/02/2017 11:13
Last modification date
20/08/2019 15:11
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