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Updated: Mar 15, 2026
Assessment of Sexual Behavior of Male Mice
Published on: March 5, 2020
Development of the main olfactory system and main olfactory epithelium-dependent male mating behavior are altered in
Jung-Mi Choi1, Sung-Soo Kim1, Chan-Il Choi1
1Department of Anatomy, Ajou University School of Medicine, Suwon 16499, South Korea;
Abstract:
In mammals, initial detection of olfactory stimuli is mediated by sensory neurons in the main olfactory epithelium (MOE) and the vomeronasal organ (VNO). The heterotrimeric GTP-binding protein Go is widely expressed in the MOE and VNO of mice. Early studies indicated that Go expression in VNO sensory neurons is critical for directing social and sexual behaviors in female mice [Oboti L, et al. (2014) BMC Biol 12:31]. However, the physiological functions of Go in the MOE have remained poorly defined. Here, we examined the role of Go in the MOE using mice lacking the α subunit of Go Development of the olfactory bulb (OB) was perturbed in mutant mice as a result of reduced neurogenesis and increased cell death. The balance between cell types of OB interneurons was altered in mutant mice, with an increase in the number of tyrosine hydroxylase-positive interneurons at the expense of calbindin-positive interneurons. Sexual behavior toward female mice and preference for female urine odors by olfactory sensory neurons in the MOE were abolished in mutant male mice. Our data suggest that Go signaling is essential for the structural and functional integrity of the MOE and for specification of OB interneurons, which in turn are required for the transmission of pheromone signals and the initiation of mating behavior with the opposite sex.
Insights
Go signaling in the main olfactory epithelium (MOE) is crucial for olfactory bulb development and mating behaviors. Loss of Go disrupts neurogenesis and alters interneuron balance, impairing sexual responses.
Area of Science:
- Neuroscience
- Olfactory System Biology
- Mammalian Sensory Physiology
Background:
- Olfactory stimuli are detected by sensory neurons in the main olfactory epithelium (MOE) and vomeronasal organ (VNO).
- The heterotrimeric GTP-binding protein Go is expressed in the MOE and VNO.
- Previous research highlighted Go's role in VNO-mediated social behaviors, but its function in the MOE was unclear.
Purpose of the Study:
- To investigate the physiological functions of Go in the MOE.
- To understand the role of Go signaling in olfactory bulb (OB) development and function.
- To determine the impact of Go deficiency on olfactory sensory neurons and associated behaviors.
Main Methods:
- Utilized genetically modified mice lacking the alpha subunit of Go.
- Examined olfactory bulb (OB) development, including neurogenesis and cell death.
- Analyzed the balance of OB interneuron subtypes (tyrosine hydroxylase-positive and calbindin-positive).
- Assessed sexual behavior and odor preference in mutant male mice.
Main Results:
- Mice lacking Go in the MOE exhibited perturbed OB development due to reduced neurogenesis and increased cell death.
- An altered balance of OB interneurons was observed, with more tyrosine hydroxylase-positive and fewer calbindin-positive interneurons.
- Mutant male mice showed abolished sexual behavior toward females and reduced preference for female urine odors.
- Olfactory sensory neurons in the MOE of mutant mice were impaired in processing pheromone signals.
Conclusions:
- Go signaling is essential for maintaining the structural and functional integrity of the MOE.
- Go signaling plays a critical role in the specification of OB interneurons.
- Proper Go function in the MOE is required for pheromone signal transmission and mating behavior initiation.
