Yes, I Am Ready Now: Differential Effects of Paced versus Unpaced Mating on Anxiety and Central Oxytocin Release in Female Rats

Abstract

Sexual activity and partner intimacy results in several positive consequences in the context of stress-coping, both in males and females, such as reduced state anxiety in male rats after successful mating. However, in female rats, mating is a rewarding experience only when the estrous female is able to control sexual interactions, i.e., under paced-mating conditions. Here, we demonstrate that sex-steroid priming required for female mating is anxiolytic; subsequent sexual activity under paced mating conditions did not disrupt this anxiolytic priming effect, whereas mating under unpaced conditions increased anxiety-related behavior. In primed females, the release of the neuropeptide oxytocin (OT) within the hypothalamic paraventricular nucleus was found to be elevated and to further increase during paced, but not unpaced mating. Central administration of an OT receptor antagonist partly prevented priming/mating-induced anxiolysis indicating the involvement of brain OT in the anxiolysis triggered by priming and/or sexual activity.These findings reveal that the positive consequences of mating in females are dependent on her ability to control sexual interactions, and that brain OT release is at least in part the underlying neurobiological correlate.

Involvement of pregnane xenobiotic receptor in mating-induced allopregnanolone formation in the midbrain and hippocampus and brain-derived neurotrophic factor in the hippocampus among female rats

“…An important aspect of this response is that it seems to be driven by paced mating, not any mating experience, as has been demonstrated for behavioral plasticity/changes in motivated processes (e.g. conditioned place preference; Camacho et al, 2009; Frye et al, 1998; García-Horsman et al, 2008; González-Flores et al, 2004; Nyuyki et al, 2011), well as neural plasticity (Arzate et al, 2012; Corona et al, 2011; Holder and Mong, 2010), involving endogenous opioids and oxytocin. It may be that PXR is necessary for behavioral-induced 3α,5α-THP biosynthesis in reward and limbic pathways mediating the behaviors assessed, as well as effects on neural plasticity, which may serve to facilitate consolidation about mating experience or challenge.…”

Oxytocin in the prelimbic medial prefrontal cortex reduces anxiety-like behavior in female and male rats

“…Separate groups of male and female rats were infused with 0.1μg/1μl OTR-A (n = 6 female; n = 5 male) (Lukas et al, 2011) or 1μl saline vehicle (n = 6 female; n = 6 male) in the PL region of the mPFC and were tested in both the EPM and SI tests. All rats underwent testing 20 min after OTR-A infusions (Ring et al, 2006; Nyuyki et al, 2011). Tests were done 5 min apart and the order of the two tests was counterbalanced among rats.…”

Oxytocin in General Anxiety and Social Fear: A Translational Approach

“…Relatively simple pharmacologic approaches using intracerebroventricular (icv) or local (PVN, central amygdala, prefrontal cortex) administration of an OXT-R agonist or antagonist have consistently shown an anxiolytic effect of synthetic or endogenous OXT in male and female rodents (53)(54)(55)(56)(57)(58). Particularly intriguing is the anxiolytic effect of endogenous brain OXT during periods of robust activation and increased central release, including lactation (51,57,59) and sexual activity in both male and female rodents (60)(61)(62). In contrast, under nonreproductive and stress-free conditions (and thus low OXT system activity), we have never been able to reveal an anxiolytic effect of brain OXT using an OXT-R antagonist.…”