THE expression of the olfactory cyclic nucleotide-gated channel (CNG1)
was studied in the rat brain. Using RT-PCR, levels of CNG1 mRNA were
determined relative to the expression of a constantly expressed gene,
ol-tubulin. RT-PCR showed that CNG1 mRNA was detectable in the pituita
ry gland, the olfactory bulb, and the cerebellum of adult and 5-day-ol
d rats. A 3.4 kb mRNA was detected in the olfactory bulb by Northern b
lotting. In situ hybridization analysis showed that CNG1 mRNA expressi
on is present in the olfactory bulb and in the Purkinje cells of the c
erebellum. RT-PCR studies on Purkinje cell-enriched cultures obtained
from the cerebellum of 16-day-old embryos (E16) confirmed the expressi
on of CNG1 mRNA in these neurones. Our results show that CNG1 is not r
estricted to the olfactory epithelium but is also present in specific
regions of the brain. These results suggest that cyclic nucleotides ma
y act in the regions that possess CNG1 gene expression to affect the e
lectrical activity of certain neurones directly.