GABA mammalian

Picrotoxin has been instmmental in estabUshing an inhibitory neurotransmitter role for the amino acid, gamma-aminobutyric acid (GABA), quantitatively the most important inhibitory neurotransmitter in the mammalian CNS. Whereas glycine is predominately localized in the spinal cord, GABA... 

GABA (y-aminobutyric acid) is an amino acid with mostly inhibitory functions in the mammalian central nervous system. Structures involved in releasing or binding GABA as a neurotransmitter constitute the GABAergic system. The GABAergic system is involved... 

GABA is the most prominent inhibitory neurotransmitter in the mammalian nervous system and acts via GABA receptors. Activation of GABAb receptors by GABA released from local spinal interneurons (Fig. 1) negatively modulates nociceptive transmission in the spinal cord. Agonists at GABAb receptors... 

Wagner, S, Castel, M, Gainer, H and Yarom, Y (1997) GABA in the mammalian suprachiasmatic nucleus and its role in diurnal rhythmicity. Nature 387 598-603. 

There is now evidence that the mammalian central nervous system contains several dozen neurotransmitters such as acetylcholine, noradrenaline, dopamine and 5-hydroxytryptamine (5-HT), together with many more co-transmitters, which are mainly small peptides such as met-enkephalin and neuromodulators such as the prostaglandins. It is well established that any one nerve cell may be influenced by more than one of these transmitters at any time. If, for example, the inhibitory amino acids (GABA or glycine) activate a cell membrane then the activity of the membrane will be depressed, whereas if the excitatory amino acid glutamate activates the nerve membrane, activity will be increased. The final response of the nerve cell that receives all this information will thus depend on the balance between the various stimuli that impinge upon it. 

GABA is also present in very high concentrations in the mammalian brain, approximately 500 jUg/g wet weight of brain being recorded for some regions Thus GABA is present in a concentration some 200-1000 times greater than neurotransmitters such as acetylcholine, noradrenaline and 5-HT. 

Conti, F., Minelliy, A., Melone, M. GABA transporters in the mammalian cerebral cortex localization, development and pathological implications. Brain Res. Rev. 2004, 45, 196-212. 

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