Immunohistochemical analysis of the expression of GABA_B-R1/R2 and mGlu1αRs in normally sleeping (NS) and sleep-deprived (SD) rats.

<p>Representative photomicrographs illustrating immunohistochemical localization of GABA_B-R1/R2 and mGlu1αR in the CA1 region of the hippocampus of NS (A) and SD (B) rats. GABA_B-R1- like immunoreactivity was well-expressed at the neuronal perikarya and cytoplasmic protein (a, b). Following sleep-deprivation, the intensity of staining and the number of neurons immunopositive to GABA_B-R1 increased (g, h). An enhanced immunoreactivity was also evident in the stratum radiatum (sr; b, h). For the GABA_B-R2 subtype, a moderate to weak immunoreactivity was observed in stratum pyramidale (sp) and sr of NS rats (c, d), with a modest increase in immunoreactivity in SD rats (i, j). mGlu1αR- like immunoreactivity was strong- to moderately- expressed in isolated pyramidal and non-pyramidal neurons in the sp, sr and stratum oriens (so; e) in NS rats. Following sleep-deprivation, the intensity of staining and the number of neurons immunopositive to mGlu1α increased (k, l compared to e, f). The immunoreactivity in dendrites and axons was also enhanced. While the staining in pyramidal/non-pyramidal neuron perikarya was uniform, it appeared punctated in dendrites and axons in both NS and SD rats. Scale Bar = 160 µm for panels on left in A & B; 20 µm for panels on right in A & B; and 5 µm for inset.