Journal of Neuroscience, Vol 7, 1159-1165, Copyright © 1987 by Society for Neuroscience
Rat brain 5-HT1C receptors are encoded by a 5-6 kbase mRNA size class and are functionally expressed in injected Xenopus oocytes
H Lubbert, TP Snutch, N Dascal, HA Lester and N Davidson
Injection of rat brain RNA into Xenopus laevis oocytes induces synthesis of
receptors that show an electrophysiological response to bath application of
serotonin. While there are at least 4 pharmacologically distinct subtypes
of 5-HT binding sites in the rat brain, we find that the pharmacological
characteristics of the predominant electrophysiologically active receptor
synthesized in Xenopus oocytes are most consistent with those of the 5-HT1C
subtype. Additional electrophysiologically active 5-HT receptor types could
not be detected. Injection of mRNA isolated from a number of rat brain
regions shows that the choroid plexus is particularly enriched for 5- HT1C
mRNA. Oocytes injected with RNA isolated from this region respond 16 or 8
times more strongly to serotonin than do oocytes injected with RNA isolated
from cortex or substantia nigra, respectively. In addition, by
fractionation of rat brain mRNA through agarose gels, we have identified a
single RNA size class of about 5-6 kbase that encodes this serotonin
receptor.