Voltage-activated current properties of male and female mouse vomeronasal sensory neurons: sexually dichotomous?

The vomeronasal organ, the chemosensory organ of the vomeronasal system, is vital in determining sexual and gender-specific behavior in mice. Here, whole-cell voltage-activated currents of individual mouse vomeronasal sensory neurons of two strains (BALB/c and CBA) were measured and correlated to sex in each strain. The average resting membrane potentials, maximal outward current magnitudes, and kinetics of activation and inactivation, were found to be independent of sex. Maximal inward current magnitudes differed significantly across gender in CBA, whereas they did not significantly differ in male and female BALB/c mice: BALB/c males -347+/-45 pA ( n=51), and females -430+/-56 pA ( n=27); CBA males -308+/-36 pA ( n=56) and females -155+/-18 pA ( n=28). These results suggest that some voltage-activated properties may differ slightly according to gender and to strain.