Éllen Almeida Nunes

Hypoestrogenism alters mood: Ketamine reverses depressive-like behavior induced by ovariectomy in rats

BACKGROUND Estrogen deficiency is associated with the onset of depressive and anxiety symptoms, cognitive impairment, and adverse consequences. We investigated depressive-like behaviors in ovariectomized rats and ketamines effect on this behavior. METHODS Twenty-eight female Wistar adult rats were initially divided into two groups: ovariectomized (OVX) and sham surgery (SHAM). Hormonal status was verified by vaginal cytology, and the rats were subjected to a forced swimming (FS) test 18 days post-surgery, an open field (OF) test 28 days post-surgery, and an elevated plus maze (EPM) test 38 days post-surgery (Experiment 1). In addition, the effect of ketamine on depressive-like behavior of the female rats was evaluated (Experiment 2). RESULTS OVX group exhibited anxiety-like behavior on EPM test (lower time spent and fewer entries in the open arms), without any difference in performance in the OF test. OVX rats showed depressive-like behavior (higher time of immobility) than SHAM rats in FS test. The SHAM group showed signs of hypoestrogenism (anestrus) at six months of age. Moreover, ketamine was able to reverse depressive-like behavior in the FS retest in both groups (OVX and SHAM). CONCLUSION Similar to the literature, we showed the antidepressant effect of ketamine in depressive female rats which was induced by ovariectomy; including in female rats submitted to sham surgery that interestingly presented a premature menopausal.

Standardized Passiflora incarnata L. Extract Reverts the Analgesia Induced by Alcohol Withdrawal in Rats

Passiflora incarnata L. (Passifloraceae) has been traditionally used for treatment of anxiety, insomnia, drug addiction, mild infections, and pain. The aim of this study was to investigate the effect of a commercial extract of P. incarnata in the analgesia induced by alcohol withdrawal syndrome in rats. In addition, brain‐derived neurotrophic factor and interleukin‐10 levels were evaluated in prefrontal cortex, brainstem, and hippocampus. Male adult rats received by oral gavage: (1: water group) water for 19 days, 1 day interval and water (8 days); (2: P. incarnata group) water for 19 days, 1 day interval and P. incarnata 200 mg/kg (8 days); (3: alcohol withdrawal group) alcohol for 19 days, 1 day interval and water (8 days); and (4: P. incarnata in alcohol withdrawal) alcohol for 19 days, 1 day interval and P. incarnata 200 mg/kg (8 days). The tail‐flick and hot plate tests were used as nociceptive response measures. Confirming previous study of our group, it was showed that alcohol‐treated groups presented an increase in the nociceptive thresholds after alcohol withdrawal, which was reverted by P. incarnata, measured by the hot plate test. Besides, alcohol treatment increased brain‐derived neurotrophic factor and interleukin‐10 levels in prefrontal cortex, which was not reverted by P. incarnata. Considering these results, the P. incarnata treatment might be a potential therapy in the alcohol withdrawal syndrome. Copyright

Morphine exposure during early life alters thermal and mechanical thresholds in rats

Morphine is an opioid analgesic used to relieve moderate‐to‐severe pain, including pain in neonates at the intensive care unit. In our previous study, we showed that repeated morphine exposure during early life could trigger long‐lasting implications on the developing nervous system, such as long‐term neurochemical and behavioral alterations in adult rats.