- The olfactory bulb contains the first synaptic relay in the olfactory pathway, the sensory system in which odorants
are detected enabling these chemical stimuli to be transformed into electrical signals and, ultimately, the perception
of odor. Acid-sensing ion channels (ASICs), a family of proton-gated cation channels, are widely expressed in
neurons of the central nervous system. However, no direct electrophysiological and pharmacological characterizations
of ASICs in olfactory bulb neurons have been described. Using a combination of whole-cell patch-clamp recordings
and biochemical and molecular biological analyses, we demonstrated that functional ASICs exist in mouse
olfactory bulb mitral/tufted (M/T) neurons and mainly consist of homomeric ASIC1a and heteromeric ASIC1a/2a
channels. ASIC activation depolarized cultured M/T neurons and increased their intracellular calcium concentration.
Thus, ASIC activation may play an important role in normal olfactory function.