Related Experiment Video
Updated: Jun 6, 2026
07:16
Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission
Published on: August 16, 2018
Probing GABA receptor function in schizophrenia with iomazenil
Kyungheup Ahn1, Roberto Gil, John Seibyl
1Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT 06516, USA.
Summary
Gamma-amino butyric acid (GABA) deficits are implicated in schizophrenia. Inducing a GABA deficit with iomazenil worsened psychosis in schizophrenia patients but not healthy controls, supporting the GABA-deficit hypothesis.
Area of Science:
- Neuroscience
- Psychiatry
- Pharmacology
Background:
- Evidence suggests Gamma-amino butyric acid (GABA) deficits contribute to schizophrenia pathophysiology.
- Pharmacologically induced GABA deficits can increase vulnerability to psychotomimetic drug effects.
Purpose of the Study:
- To test if exacerbating GABA deficits induces or unmasks psychosis in schizophrenia patients.
- To compare the effects of a transient GABA deficit in schizophrenia patients versus healthy controls.
Main Methods:
- A double-blind, randomized, placebo-controlled study using iomazenil to induce a transient GABA deficit.
- Administered iomazenil (3.7 μg IV) to stable chronic schizophrenia patients (n=13) and healthy controls (n=20).
- Assessed psychosis and perceptual alterations using standardized scales before and after iomazenil administration.
Main Results:
- Iomazenil administration increased psychotic symptoms and perceptual alterations in schizophrenia patients.
- Healthy controls did not exhibit increased psychotic symptoms or perceptual alterations after iomazenil.
- Schizophrenia patients showed greater vulnerability to iomazenil's effects compared to controls.
Conclusions:
- The findings provide further support for the GABA-deficit hypothesis of schizophrenia.
- Transient GABA deficits pharmacologically induced psychosis in schizophrenia patients, but not healthy individuals.
Related Concept Videos
01:18Antiepileptic Drugs: GABAergic Pathway Potentiators
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 their...
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
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...
01:21Antipsychotic Drugs: Typical and Atypical Agents
Antipsychotic drugs are classified into first-generation (typical) drugs including phenothiazines; and second-generation (atypical) drugs. Chlorpromazine hydrochloride (Thorazine), a phenothiazine derivative, broadly impacts the central, autonomic, and endocrine systems. This drug, along with typical agents like haloperidol (Haldol), primarily works by antagonizing D2 receptors, thus reducing dopaminergic neurotransmission. However, typical antipsychotics can cause side effects such as sedation...
01:27Psychosis: Pathophysiology of Schizophrenia and Other Psychotic Disorders
Schizophrenia is a neurodevelopmental disorder whose origins are rooted in complex genetic components. Despite our burgeoning understanding, the pathophysiology of this disorder remains incompletely deciphered.
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within the...
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within the...
01:26Psychosis: Goals of Pharmacotherapy
Antipsychotic drugs are a crucial treatment method for acute and chronic psychoses, bipolar illness, and behavioral disorders. The selection of these drugs depends on several factors, including the state of the disease, clinical judgment, possible drug interactions, and the patient's sensitivity to adverse effects. In immediate scenarios, such as delirium and dementia, short-term treatment with low doses of high-potency typical or atypical agents can effectively manage symptom exacerbation. For...
01:20Antiepileptic Drugs: Potassium Channel Activators
Ezocgabine or retigabine, an antiepileptic drug of remarkable efficacy, has revolutionized the management of seizures. It is a potassium channel activator, explicitly targeting the family of Q subtype potassium channels. It enhances the transmembrane potassium currents, regulating neuronal excitability. This action stabilizes the resting membrane potential, a pivotal factor in mitigating the hyperexcitability that characterizes epilepsy.
Ezogabine has gained approval as an adjunctive treatment...
Ezogabine has gained approval as an adjunctive treatment...