TY - JOUR
T1 - Blocking adenylyl cyclase inhibits olfactory generator currents induced by 'IP3-odors'
AU - Chen, Shan
AU - Lane, Andrew P.
AU - Bock, Roland
AU - Leinders-Zufall, Trese
AU - Zufall, Frank
PY - 2000
Y1 - 2000
N2 - Vertebrate olfactory receptor neurons (ORNs) transduce odor stimuli into electrical signals by means of an adenylyl cyclase/cAMP second messenger cascade, but it remains widely debated whether this cAMP cascade mediates transduction for all odorants or only certain odor classes. To address this problem, we have analyzed the generator currents induced by odors that failed to produce cAMP in previous biochemical assays but instead produced IP3 ('IP3-odors'). We show that in single salamander ORNs, sensory responses to 'cAMP-odors' and IP3-odors are not mutually exclusive but coexist in the same cells. The currents induced by IP3-odors exhibit identical biophysical properties as those induced by cAMP odors or direct activation of the cAMP cascade. By disrupting adenylyl cyclase to block cAMP formation using two potent antagonists of adenylyl cyclase, SQ22536 and MDL12330A, we show that this molecular step is necessary for the transduction of both odor classes. To assess whether these results are also applicable to mammals, we examine the electrophysiological responses to IP3-odors in intact mouse main olfactory epithelium (MOE) by recording field potentials. The results show that inhibition of adenylyl cyclase prevents EOG responses to both odor classes in mouse MOE, even when 'hot spots' with heightened sensitivity to IP3-odors are examined.
AB - Vertebrate olfactory receptor neurons (ORNs) transduce odor stimuli into electrical signals by means of an adenylyl cyclase/cAMP second messenger cascade, but it remains widely debated whether this cAMP cascade mediates transduction for all odorants or only certain odor classes. To address this problem, we have analyzed the generator currents induced by odors that failed to produce cAMP in previous biochemical assays but instead produced IP3 ('IP3-odors'). We show that in single salamander ORNs, sensory responses to 'cAMP-odors' and IP3-odors are not mutually exclusive but coexist in the same cells. The currents induced by IP3-odors exhibit identical biophysical properties as those induced by cAMP odors or direct activation of the cAMP cascade. By disrupting adenylyl cyclase to block cAMP formation using two potent antagonists of adenylyl cyclase, SQ22536 and MDL12330A, we show that this molecular step is necessary for the transduction of both odor classes. To assess whether these results are also applicable to mammals, we examine the electrophysiological responses to IP3-odors in intact mouse main olfactory epithelium (MOE) by recording field potentials. The results show that inhibition of adenylyl cyclase prevents EOG responses to both odor classes in mouse MOE, even when 'hot spots' with heightened sensitivity to IP3-odors are examined.
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U2 - 10.1152/jn.2000.84.1.575
DO - 10.1152/jn.2000.84.1.575
M3 - Article
C2 - 10899229
AN - SCOPUS:0033925046
VL - 84
SP - 575
EP - 580
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
SN - 0022-3077
IS - 1
ER -