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GABA (gamma-aminobutyric acid) GABA levels have been reported to be significantly decreased in platelets of autistic children when compared to controls (Rolf et al, 1993). Cohen et al (1991) suggested that GABA could mediate social avoidance behaviour in autistic individuals. In children blood GABA level decreased to low values after thyroidectomy. Increase of GABA level was revealed in thyroid hyperplasia (11 degrees) and euthyroid goiters, again showing regulatory mechanism of thyroid status (Myshunina et al, 1997). GABA content was significantly decreased in both cochlear nucleus regions of neonatal hypothyroid rats (Hebert et al, 1987). Glutamate decarboxylase (GAD), a specific marker for GABAergic neurons, was decreased in the cortical areas of hypothyroid rats (Virgili et al, 1991). Levels of glutamate dehydrogenase in the limbic system are regulated by thyroid hormones (Fernandez-Pastor et al, 1984). GABA is involved in the neural control of hypophyseal hormones, including prolactin (Rey-Roldan et al, 1997). Many fluoride compounds are now established as GABA inhibitors, such as 3-amino-4-fluorobutanoic acid (Silverman & Roscher, 1996), 4-amino-5-fluoropentanoic acid (Silverman & Invergo, 1986), etc.. The activity of aluminum fluoride complexes on GABA receptors has been shown (Ong & Kerr, 1995). GABA and TSH are antagonists (Ahren, 1989). GABA has an inhibitory effect upon TSH release in the pituitary induced by TRH, an effect which is reversed by fluoroquinolones (Roussel et al, 1988) Also see: Glutamine; Glutamate Benzodiazepine G Protein: Franek et al 1999 Further reading: Fluoro & GABA (140 related papers) Fluoride & GABA (40 related papers) ================================== ============ Ahren B - “GABA inhibits thyroid hormone secretion in the mouse” Thyroidology 1(3):105-8 (1989) Cohen IL, Sudhalter V, Pfadt A, Jenkins EC, Brown WT, Vietze PM - "Why are autism and the fragile-X syndrome associated?" Am J Hum Genet 48(2):195-202 (1991) http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=m&form=6&uid=1990832&Dopt=r Fernandez-Pastor JM, Morell M, Menendez-Patterson A, Escobar-Bueno MC - "Effect of experimental changes in thyroid function on oxidative metabolism and glutamate dehydrogenase activity in the limbic system of the rat" Rev Esp Fisiol 39(3):311-6 (1983) http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=6658147&form=6&db=m&Dopt=r Franek M, Pagano A, Kaupmann K, Bettler B, Pin JP, Blahos J - “The heteromeric GABA-B receptor recognizes G-protein alpha subunit C-termini” Neuropharmacology 38(11):1657-66 (1999) Hebert R, Langlois JM, Dussault JH - "Permanent defects in rat peripheral auditory function following perinatal hypothyroidism: determination of a critical period" Brain Res 355(2):161-70 (1985) http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=4084772&form=6&db=m&Dopt=r Myshunina TM, Bol'shova OV, Samson OIa, Kononenko VIa - "Changes in the level of gamma-aminobutyric acid in the blood of children with thyroid diseases" Fiziol Zh 43(1-2):64-9 (1997) http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=9221121&form=6&db=m&Dopt=r Ong J, Kerr DI - "Interactions of N-ethylmaleimide and aluminium fluoride with GABAB receptor function in rat neocortical slices" Eur J Pharmacol 287(2):197-200 (1995) Rey-Roldan EB, Lux-Lantos V, Chamson-Reig A, Libertun C - "In vivo interaction of baclofen, TRH and serotonin on PRL and TSH secretion in the developing and adult male and female rats" Life Sci 61(23):2283-90 (1997) http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=9408051&form=6&db=m&Dopt=r Rolf LH, Haarmann FY, Grotemeyer KH, Kehrer H - "Serotonin and amino acid content in platelets of autistic children" Acta Psychiatr Scand 87(5):312-6 (1993) http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query_old?uid=8517170&form=6&db=m&Dopt=r Roussel JP, Tapia-Arancibia L, Jourdan J, Astier H - “Effect of norfloxacin, a new quinolone, on GABA modulation of TRH-induced TSH release from perifused rat pituitaries” Acta Endocrinol (Copenh) 119(4):481-7 (1988) Silverman RB, Roscher CL - “Mechanism-based inactivation of gamma-aminobutyric acid aminotransferase by 3-amino-4-fluorobutanoic acid” Bioorg Med Chem 4(9):1521-35 (1996) Silverman RB, George C - “Inactivation of gamma-aminobutyric acid aminotransferase by (Z)-4-amino-2-fluorobut-2-enoic acid” Biochemistry 27(9):3285-9 (1988) Silverman RB, Invergo BJ - “Mechanism of inactivation of gamma-aminobutyrate aminotransferase by 4-amino-5-fluoropentanoic acid. First example of an enamine mechanism for a gamma-amino acid with a partition ratio of 0” Biochemistry 25(22):6817-20 (1986) Silverman RB, Nanavati SM - ““Selective inhibition of gamma-aminobutyric acid aminotransferase by (3R,4R),(3S,4S)- and (3R,4S),(3S,4R)-4-amino-5-fluoro-3-phenylpentanoic acids” J Med Chem 33(3):931-6 (1990) Virgili M, Saverino O, Vaccari M, Barnabei O, Contestabile A - "Temporal, regional and cellular selectivity of neonatal alteration of the thyroid state on neurochemical maturation in the rat" Exp Brain Res 1991;83(3):555-61 (1991) http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=1851100&form=6&db=m&Dopt=r
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