Journal of Anatomy



The existence of the vomeronasal organ in postnatal chimpanzees and evidence for its homology with that of humans


TIMOTHY D. SMITH a1a2c1, MICHAEL I. SIEGEL a2, CHRISTOPHER J. BONAR a3, KUNWAR P. BHATNAGAR a4, MARK P. MOONEY a2a5, ANNIE M. BURROWS a1a2, MATTHEW A. SMITH a6 and LISETTE M. MAICO a1
a1 School of Physical Therapy, Slippery Rock University, Slippery Rock PA, USA
a2 Department of Anthropology, University of Pittsburgh, Pittsburgh PA, USA
a3 Department of Anatomical Sciences and Neurobiology, Cleveland MetroParks Zoo, Cleveland OH, USA
a4 University of Louisville, School of Medicine, Louisville KY, USA
a5 Department of Oral Medicine and Pathology, University of Pittsburgh, Pittsburgh PA, USA
a6 Center for Neural Science, New York University, New York, NY, USA

Abstract

It is currently thought that New World monkeys, prosimians, and humans are the only primates to possess vomeronasal organs (VNOs) as adults. Recent studies of the human VNO suggest that previous investigations on Old World primates may have missed the VNO. We examined nasal septa from the chimpanzee (Pan troglodytes) grossly and histologically for comparison with nasal septa from humans, Old World monkeys (Macaca fascicularis, M. nemistrina) and prosimian primates (Microcebus murinus, Otolemur garnettii). Grossly, chimpanzees had depressions on the nasal septum similar to fossae reported anterior to the VNO openings in humans. Histologically, chimpanzees and humans had bilateral epithelial tubes which were above the superior margin of the paraseptal cartilages (vomeronasal cartilage homologue). The epithelial tubes had a homogeneous ciliated epithelium. These structures were thus positionally and structurally identical to the human VNO and unlike the well-developed prosimian VNOs which were surrounded by vomeronasal cartilage. Macaques had no structures which resembled the VNO of either the prosimians or humans. The results demonstrate that the VNO is present postnatally in the chimpanzee and is almost identical to the human VNO in its anatomical position and histological structure. This in turn suggests that the reported absence of the VNO in at least some adult Old World primates is artifactual, and that further study may provide evidence for its existence in other species.

(Accepted July 11 2000)


Key Words: Jacobson's organ; paraseptal cartilage; vomeronasal cartilage.

Correspondence:
c1 Correspondence to Dr Timothy D. Smith, School of Physical Therapy, Slippery Rock University, Slippery Rock, PA, 16057, USA. Tel.: +1 724-738-2885; fax: 1 724-738-2113; e-mail: timothy.smith@sru.edu