Molecular Core This Core includes a RT-PCR and multi-gene assay capacity, along with a state-of-the-art metabolic cage system. Connexin 36 expression and protein levels over age. A. Ratio of Cx 36 mRNA vs each of three housekeeping genes, Enolase (dark gray), Hprt (light gray) and Gapdh (black), which did not differ from each other in developmental expression. Mean and SE of 3 mesopontine tegmenti of 7 day, 17 day and adult rats. Note the gradual decrease in Cx 36 expression in development but with significant levels present in adults. B. Cx 36 protein levels in representative mesopontine tegmenti of 7 day, 17 day and adult rats. Levels decreased gradually from 7 to 17 days to adult, such that longer exposures (Connexin-36 hi-exp) were required to visualize protein levels in adults. Blot was reprobed for actin protein levels to verify equal loading. C. Photomicrograph of 400 um sagittal slice through a 30 day medial brainstem showing punched region (1 mm diameter) ventral to the locus coeruleus (the punch was centered anterior to the 7th nerve but included the nerve as it descended) in the SubC region. D. Cx 36 protein levels were normalized to Actin in slices containing the SubC from rats from 4 litters aged 10 days and 30 days. Note the decrease in protein levels across the developmental decrease in REM sleep. E. Cx 36 protein from these pooled samples from 10 day and 30 rats normalized to Actin loading. Actin protein levels are shown to verify equal loading.