GABA(A) Receptor β3 Subunit Expression Regulates Tonic Current in Developing Striatopallidal Medium Spiny Neurons
Megan J Janssen1, Robert P Yasuda, Stefano Vicini
1Department of Pharmacology and Physiology, Georgetown University School of Medicine Washington, DC, USA.
Frontiers in Cellular Neuroscience
|August 18, 2011
Summary
The GABA(A) receptor β3 subunit is essential for tonic inhibition in dopamine D2 receptor (D2+) medium spiny neurons (MSNs). Its removal narrows tonic current patterns and decreases D2+ MSN excitability, offering Parkinson's disease insights.
Area of Science:
- Neuroscience
- Molecular Biology
- Neuropharmacology
Background:
- The striatum controls movement via distinct medium spiny neuron (MSN) subpopulations.
- GABA-mediated tonic inhibition regulates MSN excitability and firing rates.
- The GABA(A) receptor β3 subunit was previously implicated in basal tonic currents of D2+ MSNs.
Purpose of the Study:
- To investigate the essential role of the GABA(A) receptor β3 subunit in mediating tonic currents in D2+ MSNs.
- To elucidate the impact of β3 subunit deletion on MSN excitability and tonic current patterns.
Main Methods:
- Utilized conditional β3 subunit knock-out (β3f/f(Drd2)) mice.
- Employed Cre-lox genetics with Cre recombinase under the D2 receptor (Drd2) promoter.
- Analyzed tonic current patterns and MSN excitability.
Main Results:
- Deletion of the β3 subunit resulted in narrow tonic current patterns in D2+ MSNs, contrasting with the variable patterns in wild-type mice.
- Removal of the β3 subunit significantly decreased D2+ MSN excitability.
- Evidence suggests upregulation of distinct synaptic receptors following β3 subunit removal.
Conclusions:
- The β3 GABA(A) receptor subunit is essential for striatal MSN GABA-mediated tonic current.
- Findings provide insights into potential therapeutic targets for Parkinson's disease by addressing D2+ MSN excitability imbalances.
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