Granule cell layer

Rat (Wistar) 3 wk 7 d/wk ad lib (W) 15 (increase in volume of mossy fiber zone, granule cell layer, and commissural association zone in hippocampus of offspring) Slomianka et al. 1989 PbAc... 

CYP2D6 mRNA and protein in human brain regions by RT-PCR, Northern blot, and Immunobiot, in situ hybridization and IHC shows constitutive CYP2D6 mRNA expression in neurons of cerebral cortex, Purkinje and granule cell layers of cerebellum, reticular neurons of midbrain and pyramidal neurons of C47, CA2, and CAS subfields of hippocampus. Protein found in cortex, cerebellum, midbrain, striatum, and thalamus of human brain. IHC shows CYP2D6 in dendrites of Purkinje and cortical neurons and neuronal soma (Chinta et al., 2002). 

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. 

Receptors containing the ai, a2, a3 or as subunit in combination with any of the P-subimits and the y2 subunit are most prevalent in the brain (Fig. 3). These receptors are sensitive to benzodiazepine modulation. The major receptor subtype is assembled from the subunits aiP2Y2. with only a few brain regions lacking this receptor (granule cell layer of the olfactory bulb, reticular nucleus of the thalamus, spinal cord motoneurons) (Fritschy and Mohler 1995 Pirker et al. 2000 Fritschy and Brunig 2003) (Table 1). 

Fig. 52A, B Representative micrographs of BrdU immunostaining in the olfactory bulb in control and ischemic subjects. A In the core white matter (WM) and adjacent portions of the granule cell layer the density and distribution of positive cells in either control or ischemic (example given with day 4) brains remained unchanged in the short-term survival monkey group. B In the long-term survival monkeys, however, the number of BrdU+ cells in the postischemic bulb parenchyma was increased (example given with day 44). The position of the visual field is depicted as a frame on the schematic maps upper right. Scale bar = 200 pm...

Ikai et al. (1992) reported that the VTA sends projections to the rat cerebellar cortex and deep cerebellar nuclei bilaterally, with a slight contralateral predominance. In this study, dopaminergic efferents of the A10 cell group were reported to reach mainly the granule cell layer of the cerebellar cortex in the lateral portion of the hemispheres, with additional input to the Purkinje cell layer, but sparing the molecular layer. The deep cerebellar nuclei, and in particular the lateral nucleus, were instead found to receive inputs from nondopaminergic cells of the VTA, reciprocating projections to the VTA bilaterally and with a contralateral predominance. 

In the monkey cerebellar cortex, Melchitzky and Lewis (2000) have recently described a dopaminergic innervation that matched the rat data in terms of laminar distribution (reaching mainly the granule cell layer and arborizing densely in the subjacent Purkinje cell layer), but was confined to certain lobules of the cerebellar vermis. 

The lack of correspondence between receptor protein and mRNA in some areas is likely to be due to the transport of the receptor from the site of synthesis into terminal areas. In the cerebellar cortex, for example, Di receptors synthesized in the granule cell layer are transported to the molecular layer (Mansour et al., 1992). 

The D3 receptor was also found in the hippocampal formation (granule cell layer of the dentate gyrus) and in the amygdaloid complex (anterior, basomedial and medial nuclei). In the posterior hypothalamus, D3 receptor was found to be expressed in the medial mammillary nucleus (Bouthenet et al., 1991). 

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