Immunochemical identification of subgroups of vomeronasal nerve fibers and their segregated terminations in the accessory olfactory bulb.

Vomeronasal nerve (VNN) fibers and their terminations in the accessory olfactory bulb (AOB) were studied immunohistochemically using 3 monoclonal antibodies (MAbs). One MAb (R2D5) labeled all VNN fibers. Another MAb (R4B12) labeled a subgroup of the VNN fibers which terminated in the rostrolateral glomeruli in the AOB. The third MAb (R5A10) recognized a complementary subgroup of the VNN which terminated in the caudomedial portion of the AOB. These results for the first time show occurrence of subtypes in the VNN axons with segregated terminations in the AOB.