title: Learning-induced plasticity of cortical representations does not affect GAD65 mRNA expression and immunolabeling of cortical neuropil.
abstract: Two forms of glutamic acid decarboxylase (GAD) are present in inhibitory neurons of the mammalian brain, a 65-kDa isoform (GAD65) and a 67-kDa isoform (GAD67). We have previously found that GAD67 is upregulated during learning-dependent plasticity of cortical vibrissal representations of adult mice. After sensory conditioning involving pairing stimulation of vibrissae with a tail shock, the increase in mRNA expression and density of GAD67-immunoreactive neurons was observed in barrels representing vibrissae activated during the training. In the present study, using the same experimental model, we examined GAD65 mRNA and protein levels in the barrel cortex. For this purpose, we used in situ hybridization and immunohistochemistry. No changes in the level of GAD65 mRNA expression were detected after the training. The pattern of GAD65 mRNA expression was complementary to that observed for GAD67. Immunocytochemical analysis found no changes in immunolabeling of neuropil of the barrels representing the vibrissae activated during the training. The results show that, in contrast to GAD67, cortical plasticity induced by sensory learning does not affect the expression of GAD65.
authors.affiliation: Department of Molecular and Cellular Neurobiology, Nencki Institute, 3 Pasteur Street, 02-093 Warsaw, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Lech
authors.forename: Anna
authors.initials: A
authors.lastname: Skibinska
authors.forename: Ewa
authors.initials: E
authors.lastname: Siucinska
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Kossut
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology*; D003214:Conditioning, Classical / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009415:Nerve Net / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology*; D014738:Vibrissae / Q000294:innervation / Q000502:physiology
chemical_list: D007527:Isoenzymes; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; C401141:glutamate decarboxylase 2