Ergaster

I was wondering if you'd seen this recent article:

The Anatomical Record
Volume 267, Issue 2, 2002. Pages: 166-176

Article
Histological definition of the vomeronasal organ in humans and chimpanzees, with a comparison to
other primates

Timothy D. Smith 1 2 *, Kunwar P. Bhatnagar 3, Kristin L. Shimp 1, Jonathan H. Kinzinger 1, Christopher J. Bonar 4, Annie M. Burrows 2 5, Mark P. Mooney 2 6, Michael I. Siegel 2

1School of Physical Therapy, Slippery Rock University, Slippery Rock, Pennsylvania
2Department of Anthropology, University of Pittsburgh, Pittsburgh, Pennsylvania
3Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
4Cleveland Metroparks Zoo, Cleveland, Ohio
5Department of Physical Therapy, Duquesne University, Pittsburgh, Pennsylvania
6Department of Oral Medicine and Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
email: Timothy D. Smith (timothy.smith@sru.edu)


*Correspondence to Timothy D. Smith, School of Physical Therapy, Slippery Rock University, Slippery Rock, PA 16057

Keywords
vomeronasal complex • histochemistry • mucous glands • mucins • VNO

Abstract
The vomeronasal organ (VNO) is a chemosensory structure that has morphological indications of functionality in strepsirhine and New World primates examined to date. In these species, it is thought to mediate certain socio-sexual behaviors. The functionality and even existence of the VNO in Old World primates has been
debated. Most modern texts state that the VNO is absent in Old World monkeys, apes, and humans. A recent study on the VNO in the chimpanzee (Smith et al., [2001b]) challenged this notion, demonstrating the need for further comparative studies of primates. In particular, there is a need to establish how the human/chimpanzee VNO differs from that of other primates and even nonhomologous mucosal ducts. Histochemical and microscopic morphological characteristics of the VNO and nasopalatine duct (NPD) were examined in 51 peri- and postnatal primates, including humans, chimpanzees, five species of New World monkeys, and seven strepsirhine species. The nasal septum was removed from each primate and histologically processed for coronal sectioning. Selected anteroposterior intervals of the VNO were variously stained with alcian blue (AB)-periodic acid-Schiff (PAS), PAS only, Gomori trichrome, or hematoxylin-eosin procedures. All
strepsirhine species had well developed VNOs, with a prominent neuroepithelium and vomeronasal cartilages that nearly surrounded the VNO. New World monkeys had variable amounts of neuroepithelia, whereas Pan troglodytes and Homo sapiens had no recognizable neuroepithelium or vomeronasal nerves (VNNs). Certain unidentified cell types of the human/chimpanzee VNO require further examination (immunohistochemical and electron microscopic). The VNOs of P. troglodytes, H. sapiens, and New World monkeys exhibited different histochemistry of mucins compared to strepsirhine species. The nasopalatine region showed great variation among species. It is a blind-ended pit in P. troglodytes, a glandular recess in H. sapiens, a mucous-producing duct in Otolemur crassicaudatus, and a stratified squamous passageway in all other species. This study also revealed remarkable morphological/histochemical variability in the VNO and nasopalatine regions among the primate species examined. The VNOs of humans and chimpanzees had some structural similarities to nonhomologous ciliated gland ducts seen in other primates. However, certain distinctions from the VNOs of other primates or nonhomologous epithelial structures characterize the human/chimpanzee VNO: 1) bilateral epithelial tubes; 2) a superiorly displaced position in the same plane as the paraseptal cartilages; 3) a homogeneous, pseudostratified columnar morphology with ciliated regions; and 4) mucous-producing structures in the epithelium itself. Anat Rec 267:166-176, 2002. © 2002 Wiley-Liss, Inc.

Coragyps

Thanks, Deb! I hadn't seen that!

lpetrich

So there is some small structure where the VNO ought to be, but one without nerves.

Also, William Jennings Bryan's comment about how we are "not even from American monkeys, but Old World monkeys" was meant to suggest that evolutionary biology had an extra put-down for his American audience.