Related Experiment Video

Updated: Jun 29, 2026

Investigating Drivers of Antireward in Addiction Behavior with Anatomically Specific Single-Cell Gene Expression Methods
09:29

Investigating Drivers of Antireward in Addiction Behavior with Anatomically Specific Single-Cell Gene Expression Methods

Published on: August 4, 2022

Mu-opioid receptors selectively regulate basal inhibitory transmission in the central amygdala: lack of ethanol

Maeng-Hee Kang-Park1, Brigitte L Kieffer, Amanda J Roberts

  • 1Department of Psychiatry, Duke University Medical Center, Durham, North Carolina, USA.

The Journal of Pharmacology and Experimental Therapeutics
|October 16, 2008
PubMed

Insights

Mu-opioid receptor (MOR) knockout mice show altered inhibitory signaling in the central amygdala (CeA). Ethanol

Area of Science:

  • Neuroscience
  • Pharmacology
  • Genetics

Background:

  • Endogenous opioid systems, particularly mu-opioid receptors (MOR), influence ethanol's effects.
  • MOR knockout mice exhibit reduced alcohol self-administration and anxiety-like behaviors compared to wild-type mice.
  • The central nucleus of the amygdala (CeA) is crucial for regulating alcohol and stress-related behaviors.

Purpose of the Study:

  • To investigate the neurobiological mechanisms of ethanol's action in the CeA.
  • To compare the effects of ethanol on neuronal activity in MOR knockout and wild-type mice.
  • To elucidate the roles of MOR and GABAergic systems in ethanol's reinforcing effects.

Main Methods:

  • Electrophysiological recordings (sharp-electrode and whole-cell patch) were performed on brain slices.
  • Examines evoked and spontaneous inhibitory postsynaptic currents (IPSCs) and potentials (IPSPs).
  • Analyzes spontaneous and miniature excitatory postsynaptic currents (EPSCs) in CeA neurons.

Main Results:

  • MOR knockout mice displayed significantly greater evoked IPSC/IPSP amplitudes and GABA(A) receptor-mediated inhibitory postsynaptic current frequencies in CeA neurons.
  • Ethanol's enhancement of evoked IPSPs/IPSCs and miniature IPSC frequency was similar in both MOR knockout and wild-type mice.
  • No significant differences in baseline or ethanol-affected excitatory postsynaptic currents (EPSCs) were observed between genotypes.

Conclusions:

  • MOR knockout alters baseline inhibitory neurotransmission in the CeA.
  • MOR- and GABA receptor-mediated mechanisms in the CeA may independently contribute to ethanol's reinforcing effects.
  • Pathway-specific neuronal responses within the CeA could underlie these independent mechanisms.

More Related Videos

Chronic Intermittent Ethanol Vapor Exposure Paired with Two-Bottle Choice to Model Alcohol Use Disorder05:12

Chronic Intermittent Ethanol Vapor Exposure Paired with Two-Bottle Choice to Model Alcohol Use Disorder

Published on: June 23, 2023

Flypub To Study Ethanol Induced Behavioral Disinhibition and Sensitization08:13

Flypub To Study Ethanol Induced Behavioral Disinhibition and Sensitization

Published on: May 18, 2020

Related Concept Videos

Opioid Receptors: Overview01:22

Opioid Receptors: Overview

Opioid receptors, including the mu (μ, MOR), delta (δ, DOR), and kappa (κ, KOR) types, belong to the rhodopsin family of G protein-coupled receptors. These receptors are located throughout the central and peripheral nervous systems and in non-neuronal tissues such as macrophages and astrocytes. Opioid receptor ligands can be categorized into agonists or antagonists. Highly selective agonists include [d-Ala2, MePhe4, Gly(ol)5]-enkephalin or DAMGO for MOR, [D-Pen2, D-Pen5]-enkephalin or DPDPE for...
CNS Depressants: Alcohol and Nicotine01:27

CNS Depressants: Alcohol and Nicotine

Ethanol, a clear colorless alcohol, has been consumed by humans for millennia, but its effects on the body are far from benign. At lower doses, it induces decreased inhibitions and loquaciousness, leading to its social appeal. However, it can cause severe consequences at higher doses, such as coma and respiratory depression, due to its zero-order elimination kinetics. Chronic ethanol abuse wreaks havoc on multiple organ systems, particularly the CNS and the liver. Abrupt cessation of ethanol...
Analgesia and Pain Management01:25

Analgesia and Pain Management

Pain is critical to various clinical pathologies, provoking an urgent need for effective management. Pain, whether acute or chronic, is a complex neurochemical process. Its alleviation depends on the type, with nonopioid analgesics effective for mild to moderate pain, such as musculoskeletal or inflammatory pain, while neuropathic pain responds best to anticonvulsants, tricyclic antidepressants, or serotonin/norepinephrine reuptake inhibitors. For severe acute or chronic pain, opioids may be...
Depressants01:28

Depressants

Depressant drugs, including alcohol and sedative-hypnotics, diminish central nervous system activity by enhancing the action of gamma-aminobutyric acid (GABA), a neurotransmitter that reduces brain activity and promotes relaxation. These substances can have various therapeutic uses but also pose significant risks, especially when misused or combined.
Alcohol is a common depressant that can induce a sense of relaxation and reduced inhibition at low doses. Contrary to its occasional...
Opioid Analgesics: Synthetic and Semisynthetic Opioids01:15

Opioid Analgesics: Synthetic and Semisynthetic Opioids

Synthetic and semisynthetic opioids are pivotal in pain management and tackling opioid addiction. Semisynthetic opioids, including morphinans (morphine derivatives), oxycodone, oxymorphone, hydrocodone, and hydromorphone, have improved pharmacokinetic profiles compared to morphine. Additionally, heroin and 6-MAM (6-Monoacetylmorphine) show better CNS penetration than morphine due to heightened lipid solubility. Hydromorphone, a potent opioid, undergoes hepatic metabolism to form the active...
Antidepressant Drugs: MAOIs and Other Agents01:23

Antidepressant Drugs: MAOIs and Other Agents

Atypical antidepressants, including bupropion (Wellbutrin), mirtazapine (Remeron), nefazodone (Serzone), trazodone (Desyrel), and vilazodone (Viibryd), offer unique mechanisms of action. Bupropion weakly inhibits dopamine and norepinephrine reuptake, aiding depression treatment and smoking cessation, with a low risk of sexual dysfunction. Mirtazapine enhances serotonin and norepinephrine neurotransmission, leading to sedation, increased appetite, and weight gain. As a result, it helps treat...