Related Experiment Video
Updated: Apr 16, 2026
07:16
Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission
Published on: August 16, 2018
14.4K
Dopamine directly modulates GABAA receptors.
Paul Hoerbelt1, Tara A Lindsley2, Mark W Fleck2
1Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York 12208 HoerbeP@mail.amc.edu.
Summary
Dopamine has opposing effects on mammalian GABAA receptors. It inhibits tonic currents in striatal neurons but activates some spontaneously active receptors lacking alpha subunits, suggesting complex neuromodulation.
Area of Science:
- Neuroscience
- Neuropharmacology
- Molecular Biology
Background:
- Dopamine is a key neuromodulator acting on GPCRs in mammals and ion channels in invertebrates.
- GABAA receptors are crucial inhibitory neurotransmitter receptors in the brain.
Purpose of the Study:
- To investigate the direct effects of dopamine on mammalian GABAA receptors.
- To elucidate the subunit composition and conditions under which dopamine modulates GABAA receptor activity.
Main Methods:
- Whole-cell patch-clamp electrophysiology was used to record currents in rat striatal neurons and HEK293 cells expressing specific GABAA receptor subunits.
- Mutant GABAA receptor subunits were employed to investigate the role of specific domains in dopamine's action.
Main Results:
- Dopamine directly inhibited tonic GABA-evoked currents in GABAA receptors containing α1β3 or α1β2γ2 subunits.
- Dopamine directly activated GABAA receptors containing α1β2γ2, α5β3γ2, or α1β3γ2 subunits, even in the absence of GABA.
- Dopamine activation of GABAA receptors required β and γ subunits but not α subunits, and was linked to spontaneous receptor activity.
Conclusions:
- Dopamine exhibits dual, opposing actions on different GABAA receptor populations.
- Dopamine may inhibit GABAA receptors near dopamine release sites activated by tonic GABA.
- Dopamine may enhance signaling of spontaneously active, noncanonical GABAA receptors lacking alpha subunits.
More Related Videos
Related Concept Videos
01:28Drugs Affecting GI Tract Motility: Dopamine Receptor Antagonists
1.9K
Prokinetic agents are specialized medications that stimulate gastrointestinal (GI) motility, promoting food movement through the GI tract. Dopamine, an inhibitory neurotransmitter, plays a significant role in this process, reducing GI motility and indirectly controlling the speed of digestion. Dopamine receptor antagonists, such as metoclopramide and domperidone, offer a unique advantage as prokinetic agents. By blocking the dopamine receptors, these drugs increase GI motility, improving food...
1.9K
01:18Antiepileptic Drugs: GABAergic Pathway Potentiators
1.8K
γ-aminobutyric acid or GABA, plays a pivotal role as an inhibitory neurotransmitter in the brain. GABA pathway potentiators, also known as GABAergic drugs, are a class of pharmaceutical agents designed to enhance the functioning of the GABAergic system. These medications primarily treat epilepsy, a neurological disorder characterized by recurrent seizures.
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for...
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for...
1.8K
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
5.0K
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
5.0K
01:29Drugs Affecting Neurotransmitter Synthesis
2.6K
Drugs affecting neurotransmitter synthesis can impact the adrenergic neuron and the synthesis of neurotransmitters. For example, α-methyltyrosine and carbidopa target specific enzymes involved in catecholamine synthesis. α-methyltyrosine inhibits the enzyme tyrosine hydroxylase, which converts tyrosine into dopamine. By blocking this enzyme, α-methyltyrosine reduces dopamine production and other catecholamines. Carbidopa, on the other hand, inhibits the enzyme dopa decarboxylase,...
2.6K
01:21G-Protein Gated Ion Channels
7.4K
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory...
Sensory...
7.4K
01:29Chemotherapy-Induced Nausea and Vomiting: Dopamine Receptor Antagonists
1.2K
Dopamine receptor antagonists, also known as antipsychotic agents, are critical in managing chemotherapy-induced vomiting. These antiemetic agents block dopamine receptors in the chemoreceptor trigger zone (CTZ), inhibiting signal transmission to the vomiting center. Antipsychotic agents encompass phenothiazines (PTZ), butyrophenones, benzamides, and thienobenzodiazepines (Zyprexa), which are utilized for their antiemetic and sedative properties.
Phenothiazines, such as prochlorperazine...
Phenothiazines, such as prochlorperazine...
1.2K