title: Sexual behavior and dendritic spine density of posterodorsal medial amygdala neurons in oxytocin knockout female mice.
abstract: Central oxytocin (OT) and arginine-vasopressin (AVP) have been shown to play an important role in sexual behavior and neuroendocrine secretion in rodents. The results of exogenous OT administration on sexual behaviors in male and female mice are controversial. This study aimed to analyze the role of OT in sexual behavior, the number of oocytes and the density of dendritic spines in the posterodorsal medial amygdala (MePD) of female mice with selective deletion of the OT gene (OTKO). Female C57BL/6 mice were genotyped and divided into control (WT) and OTKO groups (n=11 each). All experiments were performed in the proestrus phase. Compared to WT data, our results showed that the OTKO group had a significant increase in the latency for the display of lordosis behavior (490.8 ± 113.8 and 841.9 ± 53.9, respectively) and a decrease in both the frequency (6.3 ± 2.4 and 0.5 ± 0.4) and duration (49.3 ± 19.9 and 7.2 ± 7.1) of lordosis and a reduction in the number of oocytes (12.2 ± 0.8 and 9.9 ± 0.6). However, the OTKO group showed a higher density of proximal dendritic spines in the MePD compared to the WT group (2.4 ± 0.1 and 1.9 ± 0.1 spines/dendritic μm, respectively). No significant difference was observed in the plasma levels of AVP between the groups (OTKO: 617.1 ± 96.0 and WT: 583.3 ± 112.0 pg/mL). Our data suggest that OT plays a crucial role in the sexual behavior display, number of released oocytes and density of dendritic spines in the MePD of female mice. The AVP plasma concentration was not affected in the OTKO animals.
authors.affiliation: Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil.
authors.forename: Roberta Oriques
authors.initials: RO
authors.lastname: Becker
authors.forename: Virgínia Meneghini
authors.initials: VM
authors.lastname: Lazzari
authors.forename: Itiana Castro
authors.initials: IC
authors.lastname: Menezes
authors.forename: Mariana
authors.initials: M
authors.lastname: Morris
authors.forename: Katya
authors.initials: K
authors.lastname: Rigatto
authors.forename: Aldo B
authors.initials: AB
authors.lastname: Lucion
authors.forename: Alberto A
authors.initials: AA
authors.lastname: Rasia-Filho
authors.forename: Márcia
authors.initials: M
authors.lastname: Giovenardi
mesh_terms: D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood; D001774:Blood Chemical Analysis; D002452:Cell Count; D049229:Dendritic Spines / Q000502:physiology*; D005260:Female; D060005:Genotyping Techniques; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009865:Oocytes / Q000502:physiology; D010121:Oxytocin / Q000235:genetics / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*
chemical_list: D001127:Arginine Vasopressin; D010121:Oxytocin
keywords: Extended amygdala; OTKO mice; Ovulation; Reproductive behavior; Vasopressin