COMPARATIVE MORPHOLOGY OF THE ACCESSORY OLFACTORY-BULB IN BATS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 130  (MAR) , 349-365
Abstract
Bouin-perfused brains of 148 bats (76 spp., 48 genera, 8 families) were examined in serial sections for the presence of an accessory olfactory bulb. A moderate to well developed AOB [accessory olfactory bulb] is identified in 26 spp. Absence of an AOB in a particular species does not preclude its presence in some other species of that genus. The AOB of each species are measured and described. The unmyelinated vomeronasal nerve enters the bulb medially and posteriorly. The glomeruli, variable in diameter, appear better circumscribed than previously described. Mitral cells often form thick layers, up to 5 cells deep, which sometimes reach the dorsolateral surface of the bulb formation. External and internal plexiform layers are thin. The inner layer was found in only a few species. The internal granular layer, reaching the ventricular ependyma in some species, is a prominent component of the bulb. The pars dorsalis of the lateral olfactory tract usually courses between the mitral and internal granular layers. The chiropteran AOB does not differ significantly from that of insectivores, primates and other mammals. The occurrence of a functional vomeronasal system in the frugivorous, nectarivorous and sanguivorous Phyllostomatidae points to a primary functional role of this system in feeding strategy, at least in bats.