S. Sashihara et al., DOWN-REGULATION OF NA-RNA IN OLFACTORY-BULB TUFTED CELLS FOLLOWING DEAFFERENTIATION( CHANNEL MESSENGER), NeuroReport, 8(5), 1997, pp. 1289-1293
UNILATERAL naris cauterization blocks odorant access to ipsilateral ol
factory receptor cells and results in functional deafferentation of th
e olfactory bulb (OB). We used naris cauterization on postnatal day 2
(P2) to study the effects of deafferentation on the expression of Nachannel subunits in OB. In situ hybridization at P18 showed that expre
ssion of Na+ channel alpha II and beta I mRNA was dramatically downreg
ulated in tufted cells, while signals in mitral cells showed no detect
able changes. Our observations suggest that during critical periods of
development in some neurons, Na+ channel expression may be modulated
by physiological activity. The differential response in the tufted and
mitral cells may reflect varying degrees of dependence on afferent in
put or fundamental differences in cell properties.