Existence of Gα<i>_i2</i>-Expressing Axon Terminals in the Goat Main Olfactory Bulb

Abstract

ABSTRACT. In rodents, Gα i2 -expressing sensory neurons (SNs) that co-express vomeronasal receptor type 1 (V1R) are specifically found in the vomeronasal organ (VNO) and project their axons to the accessory olfactory bulb (AOB). In goats, however, Gα i2 /V1R-expressing SNs exist in both the VNO and the olfactory epithelium. Thus, we examined whether the Gα i2 -expressing axons functionally project to the main olfactory bulb (MOB). We analyzed the expression of Gα i2 in the olfactory bulb and found small Gα i2 -immunoreactive clusters in the MOB. The Gα i2 -immunoreactive axons in these clusters made synaptic contacts with second-order neurons in the MOB. These results suggest that some Gα i2 -expressing SNs functionally project their axons to the MOB in goats. KEY WORDS: accessory olfactory bulb, Gα i2 , goat, main olfactory bulb, projection.

The olfactory bulb and the number of its glomeruli in the common marmoset (Callithrix jacchus)

“…However, a study using larger animals, such as goats, indicated that glomeruli are absent in part of the olfactory bulb surface (Ohara et al, 2013). Surface areas containing glomeruli may actually be more related to the number of glomeruli than to olfactory bulb volume.…”

Structure and zonal expression of olfactory receptors in the olfactory epithelium of the goat, <i>Capra hircus</i>

“…Although the structure of the sheep nasal cavity is fairly similar to that in rodents [ 3 ], both the distribution of the OE in the nasal cavity and the zonal organization of the OE still have not been investigated in ungulates. Among ungulates, the goat olfactory system has been extensively characterized [ 15 , 16 , 22 , 23 ]. Moreover, the goat olfactory system is equipped with a unique subset of OSNs that express both vomeronasal type-1 receptor (V1rs) and Gαi2, a V1rs-associated G protein [ 23 ].…”