Granule cells GABAa receptors

Isokawa, M (1996) Decrement of GABAa receptor mediated inhibitory postysynaptic currents in dentate granule cells in epileptic hippocampus. J. Neurophysiol. 75 1901-1908. 

Brickley, S. G., Cull-Candy, S. G., and Farrant, M. (1996) Development of a tonic form of synaptic inhibition in rat cerebellar granule cells resulting from persistent activation of GABAA receptors. J. Physiol. 497(Pt 3), 753-759. 

Nusser, Z., Sieghart, W., and Somogyi, R (1998) Segregation of different GABAA receptors to synaptic and extrasynaptic membranes of cerebellar granule cells. J. Neurosci. 18, 1693-1703. 

Knockout mice have also revealed further subunit requirements for the assembly of particular GABAa receptor subtypes. Thus, the absence of the a6 subunit in cerebellar granule cells results in a complete loss of 5 subunit protein, although mRNA expression levels were unaffected (59,62). These results indicate that the 8 subunit cannot be incorporated in a receptor lacking a() in cerebellar granule cells. Likewise, in 50/0 mice, the levels of a4 subunit protein are reduced in all forebrain regions in which the 8 subunit is normally abundant, pointing to a preferential co-assembly of these subunits in several neuronal populations (63). 

Tretter, V., Hauer, B., Nusser, Z et al. (2001) Targeted disruption of the GABAa receptor 8 subunit gene leads to an up-regulation of y2 subunit-containing receptors in cerebellar granule cells. J. Biol. Chem. 276, 10532-10538. 

Zheng T, Santi MR, Marlier LNJ-L, Grayson DR. 1993. Expression of the mRNA encoding the (6 subunit of the GABAa receptor occurs in cerebellar granule cells only after completion of migration to the internal granule cell layers. Dev Brain Res 75 91-103. 

Nusser, Z., Roberts, J. D., Baude, A., Richards, J. G., and Somogyi, P. (1995). Relative densities of synaptic and extrasynaptic GABAA receptors on cerebellar granule cells as determined by a quantitative immunogold method. J. Neurosci. 15, 2948—2960. 

Nusser Z, Sieghart W, Stephenson FA, Somogyi P (1996b) The a6 subunit of the GABAa receptor is concentrated in both inhibitory and excitatory synapses on cerebellar granule cells. J Neurosci /6 103-114. 

Fig. 71. Bright-field photomicrographs showing cellular distribution of mRNAs of al, a6, 2, yS3, y2 and S GABAa receptor subunits in the cerebellum of the rat. Arrows indicate examples of labelled stellate/basket cells arrowheads delineate Purkinje cells. Gr, granule cells Mol, molecular layer P, Purkinje cells. Scale bar = 50 //m. Laurie et al. (1992).

Baude A, Sequier J-M, McKernan RM, Olivier KR, Somogyi P (1992) Differential subcellular distribution of the a6 subunit versus the al and /S2/3 subunits of the GABAA/benzodiazepine receptor complex in granule cells of the cerebellar cortex. Neuroscience, 51, 739-748. 

Hansen GH, Belhage B, Schousboe A (1991) Effect of GABA agonist on the expression and distribution of GABAa receptors in the plasma membrane of cultured cerebellar granule cells an immunocytochemical study. Neurosci. Lett., 124, 162-165. 

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