Related Experiment Video
Updated: Jun 23, 2026

Comprehensive Profiling of Dopamine Regulation in Substantia Nigra and Ventral Tegmental Area
Published on: August 10, 2012
Dopamine modulation of GABA tonic conductance in striatal output neurons
Megan J Janssen1, Kristen K Ade, Zhanyan Fu
1Department of Physiology and Biophysics, Georgetown University School of Medicine, Washington, DC 20007, USA. mjj34@georgetown.edu
Abstract:
We previously reported greater GABAA receptor-mediated tonic currents in D2+ striatopallidal than D1+ striatonigral medium spiny neurons (MSNs) are mediated by alpha5-subunit-containing receptors. Here, we used whole-cell recordings in slices from bacterial artificial chromosome transgenic mice to investigate the link between subunit composition, phosphorylation, and dopamine receptor activation. Whole-cell recordings in slices from delta-subunit knock-out mice demonstrate that while MSNs in wild-type mice do express delta-subunit-containing receptors, this receptor subtype is not responsible for tonic conductance observed in the acute slice preparation. We assessed the contribution of the beta1- and beta3-subunits expressed in MSNs by their sensitivity to etomidate, an agonist selective for beta2- or beta3-subunit-containing GABAA receptors. Although etomidate produced substantial tonic current in D2+ neurons, there was no effect in D1+ neurons. However, with internal PKA application or dopamine modulation, D1+ neurons expressed tonic conductance and responded to etomidate application. Our results suggest that distinct phosphorylation of beta3-subunits may cause larger tonic current in D2+ striatopallidal MSNs, and proper intracellular conditions can reveal tonic current in D1+ cells.
Related Concept Videos
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Antiepileptic Drugs: GABAergic Pathway Potentiators
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
Excitatory and Inhibitory Effects of Neurotransmitters
Neurochemical Transmission: Sites of Drug Action
G-Protein Gated Ion Channels
Sensory organs,...
Drugs Affecting Neurotransmitter Synthesis

