Methamphetamine enhances paced mating behaviors and neuroplasticity in the medial amygdala of female rats

Abstract

Methamphetamine (METH) is a psychomotor stimulant strongly associated with increases in sexual drive and behavior in women and men. Even though men and women are equally as likely to be addicted to or use METH, studies of sexual behavior often focus on male users. The paucity in studies examining the effect of METH in women is of great concern, when one considers the high correlation with sexually transmitted diseases such as HIV/AIDS and unplanned pregnancies. In fact, why METH so profoundly increases sexual drive is unknown. We have demonstrated that repeated exposure to METH enhances both receptivity and proceptivity in hormonally-primed female rats. The current study examined whether a repeated exposure to METH enhanced femaleinitiated sexual behaviors in hormonally-primed rats. In a paced mating paradigm, METH treatment significantly decreased the female's return latency following a mount (57%) and an ejaculation (44%), and the likelihood to leave the male following an intromission (37%) compared to controls. The METH-induced changes in paced mating behavior were accompanied by a 60% increase in spinophilin levels in the medial amygdala following hormonal priming and METH treatment. Taken together, these findings suggest that METH increases female sexual motivation and behavior in the rat potentially via changes in the neural substrate that require repeated exposure to the drug.

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.…”

The rat perirhinal cortex: A review of anatomy, physiology, plasticity, and function

“…The amygdala consists of a number of nuclei, including the nucleus of the lateral olfactory tract, bed nucleus of the olfactory tract, anterior amygdaloid area, accessory basal nucleus, basal nucleus and lateral nucleus (Pitkä nen et al, 2000;de Olmos et al, 2004), and the amygdala has been linked to emotion (de Vito and Smith, 1982;Ansah et al, 2010;Ponomarev et al, 2010), memory (Maren, 1999;Savage and Guarino, 2010), sexual functioning (Carrer et al, 1973;Carrer, 1978;Holder and Mong, 2010) and neuroendocrine functioning Taleisnik, 1978, 1980). From the amygdala, the perirhinal cortex receives projections from the nucleus of the lateral olfactory tract, accessory basal nucleus, basal nucleus and lateral nucleus Price, 1974, 1977;McDonald and Jackson, 1987;Pikkarainen and Pitkä nen, 2001;Furtak et al, 2007b) with area 35 receiving the heaviest projections from the amygdala compared to area 36 and the accessory basal and lateral nuclei being the most prominent origins of these projections (Pitkä nen et al, 2000).…”

Methamphetamine-enhanced female sexual motivation is dependent on dopamine and progesterone signaling in the medial amygdala

“…Despite this significant heath concern, the neural mechanisms underlying this drug-sex association are not known. We previously established a rodent model of METH-facilitated female sexual behavior in which estradiol and progesterone interact with METH to increase motivational components of female behavior and neuronal activation in the posterodorsal medial amygdala (MePD) (Holder et al, 2010; Holder and Mong, 2010). The current study more directly examines the mechanisms underlying the drug-sex interaction.…”