Effects of estradiol on depressive-like behavior of ovariectomized rats and its possible mechanism / 解剖学报

Objective To examine the effect of estradiol (E2) treatment on ovariectomy (OVX) induced depressive-like behavior and possible mechanism by measuring inflammatory biomarkers levels oi interleukin-6 (IL-6) and tumor necrosis tactor-(x (TNF-ot) and brain-derived neurotrophic factor (BDNF) expression in amygdaia nucleus. Methods Thirty nine healthy aduit 缶male SD rats were randomly divided into three groups : sham operation group (SO), ovariectomized group (OVX) and ovariectomized estradiol treatment group (OVX + E2). After 6 weeks of E2 treatment, depressive like behavior was evaluated by opening field test (OFT) and sugar water preference test (SPT). The levels of inflammatory factors IL-6 and TNF-a in amygdala were measured by ELESA, and the expression of BDNF in rat amygdala was detected by immunohistochemical staining. Results The result of the SPT showed that OVX significantly decreased the sugar intake and sugar preference rate of rats, and E2 treatment significantly increased sugar water intake and sugar water preference rate of rats. The result of the OFT showed that OVX significantly decreased the numbers of crossing and rearing of rats, and reduced the time spent in the centre ; E2 treatment significantly increased the numbers of crossing and rearing of rats, and prolonged the time spent in the centre. ELESA and immunohistochemical analysis found the levels of IL-6 and TNF-a in amygdala increased significantly, while the average absorbance (AA) of BDNF in the amygdala reduced significantly (P<0.01 respectively) of rats in OVX group when compared with the SO group. And the levels of IL-6 and TNF-a in amygdala decreased significantly (P<0.01 respectively), while the A4 of BDNF increased significantly (P< 0.05) in the amygdala of rats in the OVX+EX group when compared with the OVX group. The difference was statistically significant. Conclusion E2 treatment improved depression-like behavior of OVX rats is partly due to increased antiinflammatory and activated the BDNF expression in amygdaloid nucleus, thus enhancing the neuroprotective effect of OVX rats.

Involvement of GABAergic projection from central amygdaloid nucleus to paraventricular nucleus of hypothalamus in electroacupuncture induced regulation of gastric function in GAD2-Cre mice / 针刺研究

OBJECTIVE: To explore the effect of γ-aminobutyric acid (GABA)ergic neuronal circuit of the central amygdaloid nucleus (CeA) and the paraventricular nucleus of hypothalamus (PVN) on electroacupuncture (EA)-induced regulation of gastric function by way of CeA-PVN projection. METHODS: The present study included 3 parts: 1) C57BL/6 mice were randomly divided into control and EA groups (n=6 in each group). EA was applied to right "Weishu"(BL21, Back-shu point) and "Zhongwan"(CV12, Front-mu point) for 20 min, followed by detecting the expression of c-fos in the CeA and PVN by using immunofluorescence staining; 2) Microinjection of anterograde tracer (rAAV-EF1α-DIO-mcherry-WPRE-pA) into the CeA was conducted in GAD2-Cre mice for confirming the projection of GABAergic neurons from CeA to PVN; 3) GAD2-Cre mice were randomly divided into rAAV-DIO-mcherry (intra-CeA injection of rAAV-EF1α-DIO-mcherry-WPRE-pA), rAAV-DIO-hM3D（Gq）-mcherry(intra-CeA injection of rAAV-EF1α-DIO-hM3D(Gq)-mcherry-WPRE-pA) and rAAV-DIO-hM3D（Gq）-mcherry+EA groups(n=6 in each group). The food intake and gastric empty were detected, and the concentration of GABA in the PVN was assayed by using high performance liquid chromatography on the 28th day after intra-CeA injection. RESULTS: 1) The expression of c-fos in the CeA and PVN was significantly increased in the EA group relevant to the control group(P<0.01), suggesting an activation of neurons in both CeA and PVN after EA. 2) Following CeA injection of rAAV-EF1α-DIO-mcherry-WPRE-pA, the densely expressed virus GABAergic neurons were found in CeA and large number of projection fibers found in the PVN, suggesting a direct connection between CeA and PVN. 3) After activating the GABAergic neurons of CeA, the concentration of GABA in the PVN was obviously increased (P<0.01), the food intake and the gastric empty were considerably decreased relevant to the rAAV-DIO-mcherry group(P<0.01). Following EA intervention，the concentration of GABA in the PVN was obviously decreased(P<0.01), the food intake and the gastric empty were significantly increased relevant to the rAAV-DIO-hM3D（Gq）-mcherry group (P<0.01). CONCLUSION: EA of BL21 and CV12 (Back-shu and Front-mu acupoints) can increase food intake and gastric empty in GAD2-Cre mice, which may be achieved by suppressing the release of GABA in PVN through CeA-PVN GABAergic neural circuit.

Effects of Estradiol on Depressive Behavior and Amygdaloid NGF Expression in Ovariectomized Rats / 中国医科大学学报

Objective To observe the changes of the depressive behavior and amygdaloid nucleus nerve growth factor(NGF)expression in estro?gen?deprived female rats and explore the possible mechanism and targets of estradiol in depression treatment. Methods A total of 30 adult SD fe?male rats were randomly assigned to 3 groups:sham operation group(SHAM,n=10);ovariectomized group(OVX,n=10)and ovariectomized rats treated with estradiol group(OVX+E,n=10). The behavior changes were observed by tail suspension test(TST)and sucrose preference test (SPT) after 8?week estradiol treatment. Subsequently ,immunohistochemical staining detect NGF expression in amygdaloid nucleus. Results Compared with the SHAM group rats,sucrose preference ratio significantly decreased in SPT(P<0.01),immobile time prolonged in TST(P<0.01),serum estradiol level and amygdaloid NGF expression significantly decreased(all P<0.01). 8?week estradiol treatment ameliorated depres?sion?like behavior and increased serum E2 level and NGF expression in amygdaloid nucleus in OVX+E group rats when compared with the OVX group(all P<0.01). Conclusion Estradiol treatment can improve the depressive behavior of ovariectomized rats ,which may be related to the in?crease of serum estradiol level and the expression of NGF in amygdaloid nucleus.

Effect of Intracerebroventricular Injection of Neuropeptide S on Pain and Anxiety Behaviors in Rats with Neuropathic Pain / 中国康复理论与实践

@#Objective To investigate the effects of intracerebroventricular injection of neuropeptide S (NPS) on pain and anxiety behaviors in rats with neuropathic pain, and explore the possible mechanism. Methods 40 male Sprague-Dawley rats were randomly divided into Sham-Vehicle group, Sham-NPS group, chronic constriction injury (CCI) group, Neuropeptide S low-dose group (NPSl group, 0.1 nmol/L) and Neuropeptide S high-dose group (NPSh group, 1 nmol/L), with 8 rats in each group. Pain-related behaviors, anxiety-related behaviours,and expression of NPS receptor (NPSR) in the left amygdaloid nucleus were measured on the 14th day via intracerebroventricular injection.Results Compared with the Sham-Vehicle group, the CCI group demonstrated significant pain and anxiety behaviors 14 days after operation (P<0.01), the NPSh group significantly relieved (P<0.01). And there was no significant difference between the NPSl group and the CCI group (P>0.05). Compared with the CCI group, NPSR expression in amygdaloid nucleus increased in the NPSh group. Conclusion NPS can dose-dependently relieve the pain and anxiety behaviors in CCI rats, which may be related with the increase of NPSR in amygdaloid nucleus.

GABA in the central amygdaloid nucleus modulates the electrolyte excretion and hormonal responses to blood volume expansion in rats

We investigated the involvement of GABAergic mechanisms of the central amygdaloid nucleus (CeA) in unanesthetized rats subjected to acute isotonic or hypertonic blood volume expansion (BVE). Male Wistar rats bearing cannulas unilaterally implanted in the CeA were treated with vehicle, muscimol (0.2 nmol/0.2 µL) or bicuculline (1.6 nmol/0.2 µL) in the CeA, followed by isotonic or hypertonic BVE (0.15 or 0.3 M NaCl, 2 mL/100 g body weight over 1 min). The vehicle-treated group showed an increase in sodium excretion, urinary volume, plasma oxytocin (OT), and atrial natriuretic peptide (ANP) levels compared to control rats. Muscimol reduced the effects of BVE on sodium excretion (isotonic: 2.4 ± 0.3 vs vehicle: 4.8 ± 0.2 and hypertonic: 4.0 ± 0.7 vs vehicle: 8.7 ± 0.6 µEq·100 g-1·40 min-1); urinary volume after hypertonic BVE (83.8 ± 10 vs vehicle: 255.6 ± 16.5 µL·100 g-1·40 min-1); plasma OT levels (isotonic: 15.3 ± 0.6 vs vehicle: 19.3 ± 1 and hypertonic: 26.5 ± 2.6 vs vehicle: 48 ± 3 pg/mL), and ANP levels (isotonic: 97 ± 12.8 vs vehicle: 258.3 ± 28.1 and hypertonic: 160 ± 14.6 vs vehicle: 318 ± 16.3 pg/mL). Bicuculline reduced the effects of isotonic or hypertonic BVE on urinary volume and ANP levels compared to vehicle-treated rats. However, bicuculline enhanced the effects of hypertonic BVE on plasma OT levels. These data suggest that CeA GABAergic mechanisms are involved in the control of ANP and OT secretion, as well as in sodium and water excretion in response to isotonic or hypertonic blood volume expansion.

Role of Lateral Septum-ACh Pressor System in Central Amygdaloid Nucleus-emotional Pressor System / 医学研究杂志

Objective The present study was to analyze the role of ACh-lateral septum(SL)pressor system in the Central amygdaloid nucleus(AC)-emotional pressor circuit.Method Interurban microinjection of different drugs,then blood pressure and heart vate were vecorded.Results(1)CRF(corticotropin releasing factor)or SP(substance P)microinjection into the SL can induced pressor responses.The AC pressor responses to glutamate(Glu)could be attenuated by preinjection of CRF antagonist or SP antagonist into bilateral SL.(2)the AC pressor responses to Glu were also reduced by preinjection of atropine into either bilateral HBL,LC or RVL respectively,(3)Since lateral HB(HBL)projects to the posterior hypothalamus(HP)containing ACh-ergic neurons,and excitation of the latter produces pressor response via the RVL and LC-RVL;atropine preinjection into the HP could also decrease the HBL-and AC-pressor response.Conclusion The present results indicate that the AC produce pressor responses involved with the SL via their CRF and SP,mechanism underlying pressor response of SL is involved in pressor response of AC.

THE CONNECTION AMONG THE MARGINAL DIVISION OF STRIATUM,AMYGDALOID NUCLEUS AND BED NUCLEUS OF THE STRIA TERMINALIS IN THE RAT BRAIN AS REVEALED BY IMMUNOHISTOCHEMISTRY / 神经解剖学杂志

To understand the relationship of neurotransmitter between the striatum and limbic system such as amygdaloid nucle-us and bed nucleus of the stria terminalis. 30 male Sprague Dawley rats were used. Immunohistochemical ABC method was per-formed to detect the expression of substance P (SP), calcitonin gene-related peptide (CGRP), leucine-enkephalin (L-enk),cholecyctokinin (CCK) and neuronal nitric oxide synthase (NOS) on seetions of the brain. Some transmitters including substanceP, calcitonin gene-related peptide and cholecyctokinin were mainly distributed at the marginal division of the striatum. Theleucine-enkephalin was mainly distributed at the globus pallidus and was secondly distributed at the marginal division of the stria-tun. The neuronal nitric oxide synthase was mainly distributed at caudate putamen and the marginal division. All these transmit-ters were not only distributed at amygdaloid nucleus and bed nucleus of the stria terminalis, but also had fibers connection amongthe amygdaloid nucleus, marginal division and bed nucleus of the stria terminalis. CONCLUSION: There were special fibersconnection between the marginal division and other basal ganglia nucleus or the limbic system. The marginal division may beplayed some important functions of basal ganglia and limbic system.

Ontogeny of Adrenergic Receptors in the Rat Amygdala / 대한해부학회지

The mammalian amygdala comprises a heterogeneous complex of cytoarchitectonically, histochemically and connectionally distinct nuclei. To investigate the developmental changes and regional distributions of adrenoceptor binding sites in the adult and postnatal rat amygdala (postnatal days 0, 5, 10, 15, 20, 30), in vitro autoradiography was performed. Binding sites for the alpha1-adrenoceptor ligand [3H]-prazosin, the alpha2-adrenoceptor ligand [3H]-rauwolscine, and the beta-adrenoceptor ligand [125I]-iodocyanopindolol were visualized by the in vitro autoradiography, and anatomically localized by comparing the autoradiograms to Nissl- and acetylcholinesterase-stained sections. On toluidine blue- and acetylcholinesterase-stained sections of the amygdaloid complex of the rat, three major divisions can be distinguished: the cortical-like nuclear group, medial nuclear group, and central nuclear group. The basolateral nuclear group of the cortical-like nuclear group was divided into three subregions, the basal, the basolateral and the basomedial amygdaloid nucleus. Between the medial and the basolateral amygdaloid nucleus, the intercalated nuclei were observed. The highest number of alpha1-adrenoceptor binding sites was detected in the central and the lateral amygdaloid nucleus. The nuclei most strongly labeled by [3H]-rauwolscine were those in the medial part of the amygdaloid complex. The pattern of the beta-adrenoceptor binding was relatively diffuse, the medial amygdaloid nucleus was most strongly labeled among the amygdaloid nuclei. At the postnatal day 0, adrenergic receptor binding sites were only weakly labeled. The expression of a1-adrenoceptor binding was rapidly increased in the central amygdaloid nucleus at the postnatal day 5, and between the postnatal day 10 and 15, the concentration of bindig sites reached the adult levels. The expression of alpha2- and beta-adrenoceptor binding was increased in most amygdaloid nuclei at the postnatal day 10, and higher density was observed at the postnatal day 30. In the adult, the expression of adrenoceptor binding was relatively low in most nuclei when compared to postnatal day 30. These findings may provide evidence that alpha1-adrenoceptor is involved in regulating amygdaloid development and function more specifically than alpha2- and beta-adrenoceptor during postnatal development. These results indicate that the regional distributions of alpha1-, alpha2-, and beta-adrenoceptor show some differences from those of the other mammalian species reported.

AGING CHANGES OF NEUROTENSIN-LIKE AND GALANIN-LIKE NEURONS IN THE CENTRAL AMYGDALOID NUCLEUS OF THE RAT / 解剖学报

Aging changes of neurotensin-like (NT-L) and galanin-like (GAL-L) cell bodies and fiber terminals in the central amygdaloid nucleus between the young and old rats were studied by means of immunohistochemical and microspectrophotometric techniques. NT-L cell bodies were mainly located in the central part (CeLn) of, centrolateral amygdaloid nucleus, a few of NT-L neurons were also found in the centrolateral amygdaloid nucleus, capsular part (CeLc) and centromedial amygdaloid nucleus (CeM). NT-L fiber terminals were seen mainly in the CeLn and CeLc. GAL-L cell bodies were observed only in the CeM. A marked decrease of density of NT-L cell bodies and fiber terminals in the central amygdaloid nucleus was found in the old rats as compared with young animals. No significant age difference in number of GAL-L cell bodies was observed in the central amygdaloid nucleus, but the staining intensity of GAL-L cell bodies was reduced remarkably. The results show that there are apparent changes with aging of the NT-L and GAL-L neurons in the central amygdaloid nucleus of the rat. The significance of the changes remains to be studied further.