Advertisement

Topics

Effects of benzodiazepine treatment on cortical GABA(A) and muscarinic receptors: Studies in schizophrenia and rats.

Summary of "Effects of benzodiazepine treatment on cortical GABA(A) and muscarinic receptors: Studies in schizophrenia and rats."

Changes in cortical gamma-aminobutyric acid A (GABA(A)) receptors and muscarinic receptors have been reported in schizophrenia, a disorder treated with antipsychotic drugs and benzodiazepines. As there is a reported functional relationship between the GABAergic and cholinergic systems in the human central nervous system we have investigated whether there are changes in the GABA(A) and muscarinic receptors in the cortex of subjects from APD-treated subjects with schizophrenia and whether changes were different in subjects who had also received benzodiazepine treatment. We failed to show any strong correlations between changes in GABA(A) and muscarinic receptors in the CNS of subjects with schizophrenia. We showed that subjects with schizophrenia treated with benzodiazepines had lower levels of muscarinic receptors; which was not the case in rats treated with APDs, benzodiazepines or a combination of both drugs. Further, the benzodiazepine binding site, but not the muscimol binding site, was decreased in the parietal cortex of subjects with schizophrenia independent of benzodiazepine status at death. These data would therefore support our previously stated hypotheses that changes in the cortical cholinergic and GABAergic systems are involved in the pathophysiology of schizophrenia.

Affiliation

The Rebecca L. Cooper Research Laboratories, The Mental Health Research Institute, Parkville, Australia; The Department of Psychiatry, The University of Melbourne, Victoria, Australia.

Journal Details

This article was published in the following journal.

Name: Psychiatry research
ISSN: 0165-1781
Pages: 139-46

Links

DeepDyve research library

PubMed Articles [45356 Associated PubMed Articles listed on BioPortfolio]

The Analgesic Effects of (5R,6R)6-(3-Propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo3.2.1 Octane on a Mouse Model of Neuropathic Pain.

Both pharmacologic and genetic approaches have been used to study the involvement of the muscarinic acetylcholine system in the regulation of chronic pain. Previous studies suggest that the M2 and M4 ...

Methylene blue inhibits GABAA receptors by interaction with GABA binding site.

Methylene blue (MB) is commonly used in diagnostic procedures and is also used to treat various medical conditions. Neurological effects of MB have been reported in clinical observations and experimen...

Pharmacological characterization of the excitatory 'Cys-loop' GABA receptor family in C. elegans.

Ionotropic GABA receptors are evolutionarily conserved proteins that mediate cellular and network inhibition in both vertebrates and invertebrates. A unique class of excitatory GABA receptors has been...

Muscarinic receptor M4 positive allosteric modulators attenuate central effects of cocaine.

Cocaine addiction is a chronic brain disease affecting neurotransmission. Muscarinic cholinergic receptors modulate dopaminergic signaling in the reward system, and muscarinic receptor stimulation can...

Ketamine Increases the Function of γ-Aminobutyric Acid Type A Receptors in Hippocampal and Cortical Neurons.

The "dissociative " general anesthetic ketamine is a well-known N-methyl-D-aspartate receptor antagonist. However, whether ketamine, at clinically relevant concentrations, increases the activity of in...

Clinical Trials [4000 Associated Clinical Trials listed on BioPortfolio]

Impact of GABA-Enhancing Agents on Cortical GABA Concentrations Across the Menstrual Cycle in Women

The goal of this series of challenge studies is to examine the impact of menstrual cycle phase on cortical GABA response to administration of agents with either direct (benzodiazepines) or...

Treatment of Hepatic Encephalopathy With Flumazenil and Change in Cortical GABA Levels in MRS

The purpose of this study is to test feasibility of measuring flumazenil-induced changes in cortical GABA levels observed with localized 1H-MRS in relation to changes in severity of hepati...

PET Imaging of Peripheral Benzodiazepine Receptors in Patients With Neurocysticercosis Using [C-11]PBR28

The purpose of this protocol is to measure peripheral benzodiazepine receptors in the brain using positron emission tomography (PET) and compare the imaging results between patients and he...

Effects of GABA Modulator AZD7325 on Cutaneous Sensation

GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the human brain. For years, drugs that enhance its effects (e.g., benzodiazepines such as diazepam/Valium) have be...

Mechanisms of Hypoglycemia Associated Autonomic Dysfunction Question 2

The purpose of this study is to determine the way by which Alprazolam (Xanax) an anti-anxiety drug affects specialized molecules in your brain called GABA (A) receptors that alter your bod...

Medical and Biotech [MESH] Definitions

A GAMMA-AMINOBUTYRIC ACID derivative that is a specific agonist at GABA-B receptors (RECEPTORS, GABA-B). It is used in the treatment of spasticity, especially that due to spinal cord damage. Its therapeutic effects result from actions at spinal and supraspinal sites, generally the reduction of excitatory transmission.

Cell surface proteins which bind GAMMA-AMINOBUTYRIC ACID and control an integral membrane chloride channel. GABA-A receptors are the most prevalent inhibitory neurotransmitter receptors in the brain. Several isoforms have been cloned, and they belong to a superfamily which includes nicotinic receptors, glycine receptors, and 5HT-3 receptors. Most GABA-A receptors have separate modulatory sites sensitive to benzodiazepines and to barbiturates.

Drugs that bind to but do not activate muscarinic cholinergic receptors (RECEPTORS, MUSCARINIC), thereby blocking the actions of endogenous acetylcholine or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system. Antagonists that discriminate among the various muscarinic receptor subtypes and might allow better control of peripheral and central actions are under development.

Drugs that bind to and activate muscarinic cholinergic receptors (RECEPTORS, MUSCARINIC). Muscarinic agonists are most commonly used when it is desirable to increase smooth muscle tone, especially in the GI tract, urinary bladder and the eye. They may also be used to reduce heart rate.

Drugs that bind to and activate GAMMA-AMINOBUTYRIC ACID receptors (RECEPTORS, GABA).

Quick Search
Advertisement
 


DeepDyve research library

Relevant Topics

Psychiatry
Psychiatry is the study of mental disorders and their diagnosis, management and prevention.  Conditions include schizophrenia, severe depression and panic disorders among others. There are pharmaceutical treatments as well as other therapies to help...

Schizophrenia
Schizophrenia is a common  serious long-term mental health condition that affects 5 in 1000 in the UK. It causes a range of different psychological symptoms; hallucinations, delusions, muddled thoughts based on the hallucinations or delusions and ch...


Searches Linking to this Article