The Role of Hippocampal Estradiol Receptor-α in a Perimenopausal Affective Disorders-Like Rat Model and Attenuating of Anxiety by Electroacupuncture

Electroacupuncture Pretreatment Prevents Cognitive Impairment Induced by Cerebral Ischemia-Reperfusion via Adenosine A1 Receptors in Rats

A previous study has demonstrated that pretreatment with electroacupuncture (EA) induces rapid tolerance to focal cerebral ischemia. In the present study, we investigated whether adenosine receptor 1 (A1 R) is involved in EA pretreatment-induced cognitive impairment after focal cerebral ischemia in rats. Two hours after EA pretreatment, focal cerebral ischemia was induced by middle cerebral artery occlusion for 120 min in male Sprague-Dawley rats. The neurobehavioral score, cognitive function [as determined by the Morris water maze (MWM) test], neuronal number, and the Bax/Bcl-2 ratio was evaluated at 24 h after reperfusion in the presence or absence of CCPA (a selective A1 receptor agonist), DPCPX (a selective A1 receptor antagonist) into left lateral ventricle, or A1 short interfering RNA into the hippocampus area. The expression of the A1 receptor in the hippocampus was also investigated. The result showed that EA pretreatment upregulated the neuronal expression of the A1 receptor in the rat hippocampus at 90 min. And EA pretreatment reversed cognitive impairment, improved neurological outcome, and inhibited apoptosis at 24 h after reperfusion. Pretreatment with CCPA could imitate the beneficial effects of EA pretreatment. But the EA pretreatment effects were abolished by DPCPX. Furthermore, A1 receptor protein was reduced by A1 short interfering RNA which attenuated EA pretreatment-induced cognitive impairment.

Osthole Ameliorates Estrogen Deficiency-Induced Cognitive Impairment in Female Mice

Loss of endogenous estrogen and dysregulation of the estrogen receptor signaling pathways are associated with an increase in risk for cognitive deficit and depression in women after menopause. Estrogen therapy for menopause increases the risk of breast and ovarian cancers, and stroke. Therefore, it is critical to find an alternate treatment for menopausal women. Osthole (OST), a coumarin, has been reported to have neuroprotective effects. This study examined whether OST improves ovariectomy (OVX)-induced cognitive impairment, and alleviates anxiety- and depression-like behaviors induced by OVX in mice. Adult female C57BL/6J mice were ovariectomized and then treated with OST at a dose of 30 mg/kg for 14 days. At the end of the treatment period, behavioral tests were used to evaluate spatial learning and memory, recognition memory, anxiety- and depression-like behaviors. A cohort of the mice were sacrificed after 14 days of OST treatment and their hippocampi were collected for measurement of the proteins of interest using western blot. OVX-induced alteration in the levels of proteins was accompanied by cognitive deficit, anxiety- and depression-like behaviors. OST treatment improved cognitive deficit, alleviated anxiety- and depression-like behaviors induced by OVX, and reversed OVX-induced alterations in the levels of synaptic proteins and ERα, BDNF, TrKB, p-CREB, p-Akt and Rac1 in the hippocampus. Therefore, reversal of OVX-induced decrease in the levels of hippocampal proteins by OST might contribute to the effects of OST on improving cognitive deficit and alleviating anxiety- and depression-like behaviors induced by OVX.

An estradiol-independent BDNF-NPY cascade is involved in the antidepressant effect of mechanical acupuncture instruments in ovariectomized rats

Menopause-related depression devastates women's quality of life after middle age. Previous research has shown that estrogen hormone therapy has serious adverse effects; thus, complementary and integrative therapies have been considered clinically. The present study investigates whether stimulation of an acupoint using a mechanical acupuncture instrument (MAI) can mitigate depression-like behavior caused by estrogen deficiency in ovariectomized (OVX) rats. The animals were divided into Sham OVX, OVX, OVX + Sameumgyo (SP6) and OVX + NonAcu (non-acupuncture point) groups. MAI stimulation significantly increased the total distance traveled in the open-field test and the number of open-arm entries in the elevated plus maze and decreased the duration of immobility in the forced swim test. In addition to this decrease in depression-like behavior, brain-derived neurotrophic factor (BDNF) and neuropeptide Y (NPY) release increased in the hippocampus in response to MAI treatment, but estradiol levels did not recover. Furthermore, microinjection of the BDNF receptor antagonist ANA-12 (0.1 pmol/1 μl) into the hippocampus before MAI stimulation significantly suppressed the recovery of NPY levels. Taken together, these findings indicate that MAI stimulation at SP6 facilitates an estradiol-independent BDNF-NPY cascade, which may contribute to its antidepressant effects in OVX rats, an animal model of menopausal disorders.