Vomeronasal organ ablation elicits chemosensory dysfunction and abnormal behavior in mice

Abstract

This study aimed to examine whether the vomeronasal organ (VNO) is a prerequisite in mice to acquire essential information from various social odors and whether long-term VNO dysfunction can elicit behavioral and physiological changes in mice. We used binary choice tests and habituation-dishabituation tests to measure the abilities of male mice to recognize social odors. We found that males with the VNO ablation failed to show olfactory preferences between the odors of mate versus non-mate females, offspring versus non-offspring pups, or oppositesex conspecifics versus predators (cats or rats), but were capable of discriminating between the two treatments in each of the paired odors, suggesting that male mice with VNO ablation might smell out the chemical differences of the two types of odors, but could not extract the biological information contained in the odors. Furthermore, prolonged VNO deficiency resulted in a reduction in crossing behavior in a light/dark box, the frequency of urine marking, and the time spent in the center in an open field. These results indicate that chronic VNO dysfunction led to anxiety-like or submissive behavior. In addition, males with VNO ablation had atrophic adrenal glands and hypertrophic preputial glands, suggesting that VNO dysfunction could damage the physiological conditions to buffer the stress and that pheromone perception deficiency might enhance self-odor production in mice.

Conditioned odor aversion induces social anxiety towards females in wild‐type and TrpC2 knockout male mice

“…This behavioral phenotype was explained by the inability of TrpC2 −/− males to detect VNO‐mediated signals, which is considered essential for the discrimination between sex‐specific pheromones (Ibarra‐Soria et al ; Isogai et al ; Stowers et al ). Our results demonstrate for the first time that TrpC2 −/− males can acquire sex‐specific COA, similar to the abilities of WT males, and thus support previous studies reporting that sexually naïve males with surgically ablated VNOs can discriminate between female and male conspecifics' urine (Keller et al ; Liu et al ; Pankevich et al ).…”

Vomeronasal organ lesion disrupts social odor recognition, behaviors and fitness in golden hamsters

“…VNO removal (VNOx) and bilateral accessory olfactory bulb lesions clearly disrupt the pregnancy block effect (Lloyd-Thomas & Keverne 1982), copulatory behavior (Powers & Winans 1975;Meredith 1986;Keverne 2004;Keller et al 2006;Jakupovic et al 2008), reproductive behavior and intersexual attraction (Bellringer et al 1980;Martinez-Ricos et al 2008) in mice. Our previous studies indicate that chronic VNO dysfunction leads to anxiety-like or submissive behavior in mice, and that males with VNO ablation have atrophic adrenal glands and hypertrophic preputial glands (Liu et al 2010b).…”

“…Vomeronasal organs removal surgery was accomplished as previously described (Liu et al 2010b). Briefly, anesthetized (50 mg/kg, sodium pentobarbital) males (n = 15) and females (n = 15) were lying on their back on a specially designed sloping table, with their head fixed with holders.…”

“…between predator odor and sex pheromones). There are also no studies examining whether VNO dysfunction induces anxiety and reduces aggressive behavior in golden hamsters, as in mice (Clancy et al 1984;Liu et al 2010b). No studies investigate whether long-term VNO dysfunction affects the fitness and reproductive ability of the golden hamster.…”

“…The two-choice test and the habituation-dishabituation test were used to examine the golden hamster's social recognition and olfactory discrimination ability between a predator odor and sex pheromones, respectively (Liu et al 2010b). Anal gland secretion of Siberian weasels (Mustela sibirica Pallas, 1773), which arouses higher cortisol level and lower aggression of male golden hamsters, is used as the predator odor (Zhang et al 2003).…”