DIAZEPAM IS A BENZODIAZEPINE THAT BINDS TO A SPECIFIC SUBUNIT ON THE GABA RECEPTOR AT A SITE THAT IS DISTINCT FROM THE BINDING SITE OF THE ENDOGENOUS GABA MOLECULE. THE GABA RECEPTOR IS AN INHIBITORY CHANNEL WHICH, WHEN ACTIVATED, DECREASES NEURONAL ACTIVITY. BECAUSE OF THE ROLE OF DIAZEPAM AS A POSITIVE ALLOSTERIC MODULATOR OF GABA, WHEN IT BINDS TO BENZODIAZEPINE RECEPTORS IT CAUSES INHIBITORY EFFECTS. THIS ARISES FROM THE HYPERPOLARIZATION OF THE POST-SYNAPTIC MEMBRANE OWING TO THE CONTROL EXERTED OVER NEGATIVE CHLORIDE IONS BY GABAA RECEPTORS. BENZODIAZEPINES INCLUDING DIAZEPAM HOWEVER, DO NOT HAVE ANY EFFECT ON THE LEVELS OF GABA IN THE BRAIN. DIAZEPAM APPEARS TO ACT ON AREAS OF THE LIMBIC SYSTEM, THALAMUS AND HYPOTHALAMUS, INDUCING ANXIOLYTIC EFFECTS. ITS ACTIONS ARE DUE TO THE ENHANCEMENT OF GABA ACTIVITY. BENZODIAZEPINE DRUGS INCLUDING DIAZEPAM INCREASE THE INHIBITORY PROCESSES IN THE CEREBRAL CORTEX.