GABA transmission

Jayaram P, Steketee J.D. Effects of cocaine-induced behavioural sensitization on GABA transmission within rat medial prefrontal cortex. Eur. J. Neurosci. 21 2035, 2005. 

The precise mechanism of action of valproate in facilitating GABA transmission is still uncertain. There is evidence that the drug can facilitate... 

In CONCLUSION, epilepsy is a term used to describe a variety of recurrent symptoms which result from the synchronous or sustained discharge of a group of neurons. It is not clear which specific abnormality in synaptic function is associated with epilepsy, but there is some evidence that an impairment of inhibitory transmission in the neocortex and hippocampus may be primarily involved. The possible causative role of GABA is supported by the fact that many clinically useful anticonvulsants facilitate GABA transmission. Other anticonvulsants may owe their efficacy to their ability to stabilize cation movements across neuronal membranes and /or to affect the phosphorylation of membrane proteins. 

Lewis DA, Volk DW, Hashimoto T. Selective alterations in prefrontal cortical GABA transmission in schizophrenia a novel target for the treatment of working memory dysfunction. Psychopharmacology 2004 174 143-150. 

The abnormality in the inhibitory action of GABA transmission in the brain and/or the release of excitatory glutamate may be implicated in the... 

Tolerance may result from a compensatory biochemical cell response to continued exposure to opioid. In short, both physical dependence and tolerance may follow the operation of homeostatic adaptation to continued high occupancy of opioid receptors. Changes of similar type may occur with GABA transmission, involving benzodiazepines. 

Carbamazepine is licenced as an alternative to lithium for prophylaxis of bipolar affective disorder, although clinical trial evidence is actually stronger to support its use in the treatment of acute mania. Carbamazepine appears to be more effective than lithium for rapidly cycling bipolar disorders, i.e. with recurrent swift transitions from mania to depression. It is also effective in combination with lithium. Its mode of action is thought to involve agonism of inhibitory GABA transmission at the GABA-benzodiazepine receptor complex (see also Epilepsy, p. 417). 

Drug obtained form the seeds of fish beans (used to poison fish) of the Anamirta species. Convulsant. Blocks GABA transmission blocks presynaptic inhibition. 120 mg apparently lethal for cat, 16 mg lethal in guinea pig, 100-200 mg lethal in man GI upset, diarrhoea, fever, convulsions. 

Sherif, R M., Tawati, A. M., Ahmed, S. S., and Sharif, S. 1. 1997. Basic aspects of GABA-transmission in alcoholism, with particular reference to GABA-transaminase. Eur. Neuropsychopharm. 7 1-7. 

Daoust, M., Salgaut, C., Lhuintre, J. P., Moore, N., Flipo, J. L., and Boismare, F. 1987. GABA transmission, but not benzodiazepine receptor stimulation, modulates ethanol intake by rats. Alcohol 4 469-72. 

Phenobarbital is very similar to phenytoin in use and not effective in absence seizures. It appears to work, at least in part, by enhancing GABA transmission. 

As mentioned in the preceding text, striatal GABAergic projection neurons do contain CB, receptors (Herkenham, Lyrm, de Costa, et al., 1991) and their activation stimulates GABA transmission (Maneuf et al., 1996 Romero, de Miguel, et al., 1998), which would result in a greater inhibition of nigral dopamine neurons. 

The mechanism by which catatonia is precipitated by benzodiazepine withdrawal is not known the authors speculated that it may involve a rapid reduction in GABA transmission. 

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