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Background Depression is a serious and common psychiatric disorder generally affecting more women than men. A woman’s risk of developing depression increases steadily with age, and higher incidence is associated with the onset of menopause. Here we evaluated the antidepressant properties of Asparagus cochinchinensis (AC) extract and investigated its underlying mechanisms in a rat menopausal depression model. Methods To model this menopausal depression, we induced a menopause-like state in rats via ovariectomy and exposed them to chronic unpredictable mild stress (CUMS) for 6 weeks, which promotes the development of depression-like symptoms. During the final 4 weeks of CUMS, rats were treated with either AC extract (1000 or 2000 mg/kg, PO), which has been reported to provide antidepressant effects, or with the tricyclic antidepressant imipramine (10 mg/kg, IP). Results We report that CUMS promotes depression-like behavior and significantly increases serum corticosterone and inflammatory cytokine levels in the serum of ovariectomized (OVX) rats. We also found that CUMS decreases the expression of brain-derived neurotrophic factor (BDNF) and its primary receptor, tropomyosin receptor kinase B (TrkB), in OVX rats, and treatment with AC extract rescues both BDNF and TrkB expression levels. Conclusion These results suggest that AC extract exerts antidepressant effects, possibly via modulation of the BDNF-TrkB pathway, in a rat model of menopausal depression.

The dissociative anesthetic phencyclidine (PCP) and PCP derivatives, including 4&prime, F-PCP, are illegally sold and abused worldwide for recreational and non-medical uses. The psychopharmacological properties and abuse potential of 4&prime, F-PCP have not been fully characterized. In this study, we evaluated the psychomotor, rewarding, and reinforcing properties of 4&prime, F-PCP using the open-field test, conditioned place preference (CPP), and self-administration paradigms in rodents. Using Western immunoblotting, we also investigated the expression of dopamine (DA)-related proteins and DA-receptor-mediated downstream signaling cascades in the nucleus accumbens (NAc) of 4&prime, F-PCP-self-administering rats. Intraperitoneal administration of 10 mg/kg 4&prime, F-PCP significantly increased locomotor and rearing activities and increased CPP in mice. Intravenous administration of 1.0 mg/kg/infusion of 4&prime, F-PCP significantly enhanced self-administration during a 2 h session under fixed ratio schedules, showed a higher breakpoint during a 6 h session under progressive ratio schedules of reinforcement, and significantly altered the expression of DA transporter and DA D1 receptor in the NAc of rats self-administering 1.0 mg/kg 4&prime, F-PCP. Additionally, the expression of phosphorylated (p) ERK, pCREB, c-Fos, and FosB/&Delta, FosB in the NAc was significantly enhanced by 1.0 mg/kg 4&prime, F-PCP self-administration. Taken together, these findings suggest that 4&prime, F-PCP has a high potential for abuse, given its robust psychomotor, rewarding, and reinforcing properties via activation of DAergic neurotransmission and the downstream signaling pathways in the NAc.