SIZE OF THE VOMERONASAL NEUROEPITHELIUM IN TWO SPECIES OF MICROTUS WITH DIFFERING LEVELS OF PATERNAL BEHAVIOR

Abstract Recent studies have suggested that the relatively large size of the vomeronasal neuroepithelium (VNNE) in the male mammal may be related inversely to the amount of parental care contributed. We tested this hypothesis using 2 species of Microtus that differ in reproductive strategies and in level of care of the offspring. We studied the nasal tissues of 8 male meadow voles (Microtus pennsylvanicus) and 8 male prairie voles (M. ochrogaster), captured between June and August, 1998. The heads were prepared histologically for serial sectioning at 10–16 μm, and stained with hematoxylin and eosin. Sections were examined by light microscopy, and the VNNE was quantified for each specimen using a computer 3-dimensional reconstruction technique. Receptor cells also were quantified with a Leica photomicroscope using an ocular grid calibrated by a stage micrometer. No (P > 0.05) differences occurred between species for length or volume of the VNNE when expressed as absolute measures or as ratios of somatic me...