Differential localization of GABAA receptor subunits in relation to rat striatopallidal and pallidopallidal synapses


As a central integrator of basal ganglia function, the external segment of the globus pallidus (GP) plays a critical role in the control of voluntary movement. The GP is composed of a network of inhibitory GABA-containing projection neurons which receive GABAergic input from axons of the striatum (Str) and local collaterals of GP neurons. Here, using electrophysiological techniques and immunofluorescent labeling we have investigated the differential cellular distribution of a1, a2 and a3 GABAA receptor subunits in relation to striatopallidal (Str-GP) and pallidopallidal (GP-GP) synapses. Electrophysiological investigations showed that zolpidem (100 nm; selective for the a1 subunit) increased the amplitude and the decay time of both Str-GP and GP-GP IPSCs, indicating the presence of the a1 subunits at both synapses. However, the application of drugs selective for the a2, a3 and a5 subunits (zolpidem at 400 nm, L-838,417 and TP003) revealed differential effects on amplitude and decay time of IPSCs, suggesting the nonuniform distribution of non-a1 subunits. Immunofluorescence revealed widespread distribution of the a1 subunit at both soma and dendrites, while double- and triple-immunofluorescent labeling for parvalbumin, enkephalin, gephyrin and the ?2 subunit indicated strong immunoreactivity for GABAAa3 subunits in perisomatic synapses, a region mainly targeted by local axon collaterals. In contrast, immunoreactivity for synaptic GABAAa2 subunits was observed in dendritic compartments where striatal synapses are preferentially located. Due to the kinetic properties which each GABAAa subunit confers, this distribution is likely to contribute differentially to both physiological and pathological patterns of activity.

Publication DOI: https://doi.org/10.1111/j.1460-9568.2010.07552.x
Divisions: College of Health & Life Sciences > Aston Pharmacy School
College of Health & Life Sciences > Clinical and Systems Neuroscience
College of Health & Life Sciences > Aston Institute of Health & Neurodevelopment (AIHN)
College of Health & Life Sciences
Uncontrolled Keywords: globus pallidus,immunofluorescence,zolpidem,Neuroscience(all)
Publication ISSN: 1460-9568
Last Modified: 03 Jan 2024 17:29
Date Deposited: 11 Mar 2019 18:07
Full Text Link: http://onlineli ... 7552.x/abstract
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2011-03
Published Online Date: 2011-01-11
Authors: Gross, Anna
Sims, Robert
Swinny, J.D.
Sieghart, W.
Bolam, Paul J.
Stanford, Ian (ORCID Profile 0000-0002-5677-8538)



Version: Accepted Version

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