OBJECTIVES: To investigate the regulatory role of astrocytes in the dorsomedial hypothalamus (DMH) during sevoflurane anesthesia emergence. METHODS: Forty-two male C57BL/6 mice were randomized into 6 groups (n=7) for assessing astrocyte activation in the dorsomedial hypothalamus (DMH) under sevoflurane anesthesia. Two groups of mice received microinjection of agfaABC1D promoter-driven AAV2 vector into the DMH for GCaMP6 overexpression, and the changes in astrocyte activity during sevoflurane or air inhalation were recorded using calcium imaging. For assessing optogenetic activation of astrocytes, another two groups of mice received microinjection of an optogenetic virus or a control vector into the DMH with optic fiber implantation, and sevoflurane anesthesia emergence was compared using behavioral experiments. In the remaining two groups, electroencephalogram (EEG) recording during sevoflurane anesthesia emergence was conducted after injection of the hChR2-expressing and control vectors. Anesthesia induction and recovery were assessed by observing the righting reflex. EEG data were recorded under 2.0% sevoflurane to calculate the burst suppression ratio (BSR) and under 1.5% sevoflurane for power spectrum analysis. Immunofluorescence staining was performed to visualize the colocalization of GFAP-positive astrocytes with viral protein signals. RESULTS: Astrocyte activity in the DMH decreased progressively as sevoflurane concentration increased. During 2.0% sevoflurane anesthesia, the mice injected with the ChR2-expressing virus exhibited a significantly shortened wake-up time (P<0.05), and optogenetic activation of the DMH astrocytes led to a marked reduction in BSR (P<0.001). Under 1.5% sevoflurane anesthesia, optogenetic activation resulted in a significant increase in EEG gamma power and a significant decrease in delta power in ChR2 group (P<0.01). CONCLUSIONS Optogenetic activation of DMH astrocytes facilitates sevoflurane anesthesia emergence but does not significantly influence anesthesia induction. These findings offer new insights into the mechanisms underlying anesthesia emergence and may provide a potential target for accelerating postoperative recovery and managing anesthesia-related complications.
Animals ; Astrocytes/physiology* ; Sevoflurane ; Mice, Inbred C57BL ; Mice ; Male ; Electroencephalography ; Anesthetics, Inhalation/pharmacology* ; Hypothalamus/cytology* ; Anesthesia Recovery Period ; Methyl Ethers/pharmacology*

OBJECTIVE: To explore the effects of taurolithocholic acid (tLCA) and chenodeoxycholic acid (CDCA) on the expression of aorexigenic neuropeptide in mouse hypothalamus GT1-7 cells. METHODS: Mouse hypothalamic GT1-7 cells were treated with culture medium containing 10% FBS (control group, =3) or with 10 nmol/L, 100 nmol/L, 1 μmol/L and 10 μmol/L tLCA (tLCA group, =3) or CDCA (CDCA group, =3) for 12, 24 or 48 h. Real-time PCR was performed to determine the expression levels of proopiomelanocortin (POMC) mRNA in the cells, and the production levels of α-melanocyte-stimulating hormone (α-MSH) were assessed using an ELISA kit. Signal transduction and activator of transcription 3 phosphorylation (p-STAT3), threonine kinase phosphorylation (p-AKT), suppressor of cytokine signaling 3 (SOCS3), G protein-coupled bile acid receptor-1 (TGR5) and farnesoid X receptor (FXR) protein were detected by Western blotting. RESULTS: Western blotting results showed that mouse hypothalamic GT1-7 cells expressed two bile acid receptors, TGR5 and FXR, whose expressions were regulated by bile acids. Real-time PCR showed that the expression of POMC mRNA was significantly increased in the cells after treatment with 10 μmol/L tLCA or CDCA for 24 h. POMC-derived anorexigenic peptide α-MSH increased significantly in GT1-7 cells after treatment with 10 μmol/L tLCA or CDCA for 24 h. Treatment of the cells with tLCA or CDCA significantly increased the expressions of intracellular signaling proteins including p-STAT3, p-AKT and SOCS3. CONCLUSIONS Mouse hypothalamic GT1-7 cells express bile acid receptors TGR5 and FXR. Bile acids tLCA or CDCA can promote the expression of POMC mRNA and increase the production of the anorexigenic peptide α-MSH. The intracellular signaling proteins p-AKT, p-STAT3 and SOCS3 are likely involved in bile acid-induced anorexigenic peptide production.
Animals ; Cell Line ; Chenodeoxycholic Acid ; pharmacology ; Gene Expression Regulation ; drug effects ; Hypothalamus ; cytology ; Mice ; Neuropeptides ; genetics ; metabolism ; Pro-Opiomelanocortin ; genetics ; RNA, Messenger ; genetics ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; drug effects ; Suppressor of Cytokine Signaling 3 Protein ; metabolism ; Taurolithocholic Acid ; pharmacology ; alpha-MSH ; genetics

Leydig cells are the major source of androgens in males. Stem cells can be induced to differentiate into androgen-secreting Leydig like cells, whose functions are regulated by the hypothalamus and pituitary, so that they precisely secret the necessary hormones to maintain physiological function. Therefore, the establishment of an effective protocol to induce the differentiation of stem cells into androgen-secreting cells is very helpful for the treatment of hypogonadism caused by abnormalities of Leydig cells. This review outlines the recent findings concerning the differentiation of stem cells into androgen-secreting cells.
Androgens ; secretion ; Cell Differentiation ; physiology ; Humans ; Hypogonadism ; therapy ; Hypothalamus ; physiology ; Male ; Pituitary Gland ; physiology ; Stem Cells ; cytology ; secretion

OBJECTIVETo investigate the effect of voluntary exercise on the proliferation and differentiation of hypothalamus progenitor cells in adult rats.

METHODSMale Wistar rats were divided into voluntary exercise (EX) and sedentary (SE) groups, both of which were further divided into 6 subgroups for observation on days 6, 13, 23, 33, 43 and 53. Bromodeoxyuridine (BrdU) was intraperitoneally injected daily for 5 consecutive days after commencing voluntary exercise, and at the specified time points during voluntary exercise, the rats' brains were removed to observe the numbers of BrdU-positive cells in the hypothalamus.

RESULTSImmunohistochemical analysis showed that the numbers of BrdU-positive cells in the hypothalamus of EX subgroups were significantly greater than those of SE subgroups on days 23, 33, 43 and 53. In EX group, the number of BrdU-positive cells double-stained for a mature neuron marker increased after 43 days of voluntary exercise, which did not occur in SE group.

CONCLUSIONLong-term voluntary exercise can promote the proliferation of neuronal progenitor cells in the hypothalamus and their differentiation into neurons.

Animals ; Cell Differentiation ; Cell Proliferation ; Hypothalamus ; cytology ; Male ; Neurons ; cytology ; Physical Conditioning, Animal ; Rats ; Rats, Wistar ; Stem Cells ; cytology

OBJECTIVETo establish the in vitro model of PGE2 released by hypothalamic neurocytes under rrIL-1beta in vitro interference, and investigate the correlation of the PGE2 content and the effect of the drug effect concentration in the model under the effect of Bupleurum injection.

METHODHypothalamic neurocytes were cultured in vitro, and added with rrIL-1beta (40 microg x L(-1)) stimulation. Cell sap was collected at different time points. ELISA was adopted to determine the content of PGE2 in cell sap collected at different time points. Hypothalamic neurocytes were cultured in vitro, added with rrIL-1beta (40 microg x L(-1)) stimulation and then different concentrations of Bupleurum injection. The changes in the content of PGE2 in cell supernatant were detected by ELISA. An analysis was made on the linear relationship between the sample concentration and the inhibition rate of PGE2.

RESULTThe rrIL-1 cells could stimulate in vitro cultured hypothalamic neurocytes to release PGE2 and reach the peak at 10 h. Bupleurum injection could significantly interfere the release of PGE2 in the in vitro model (P < 0.01, P < 0.05), with a certain linear relationship between the interference effect and the effect concentration of Bupleurum injection (r = 0.911, P < 0.01).

CONCLUSIONThe rrIL-1 cells could stimulate in vitro cultured hypothalamic neurocytes to release PGE2, with a good correlation between the inhibition and generation effects of PGE2 and the drug concentration.

Animals ; Biological Assay ; Bupleurum ; chemistry ; Cells, Cultured ; Dinoprostone ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Female ; Hypothalamus ; cytology ; drug effects ; metabolism ; Neurons ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To observe the GluR2 expression in rat inferior colliculus (IC) in different developmental stages, and to investigate its developmental change and relationship with the synapse development. METHOD: The expression of GluR2 and synaptophysin(SYP) in IC were detected by double immunofluorescence method. RESULT: (1) All sorts of neurons in IC expressed GluR2 in every postnatal groups, and the GluR2 expression in P6w groups was higher than that in other groups. (2) The expression of GluR2 were different in different subnucleus of IC. (3) All sorts of neurons in IC expressed SYP in every postnatal groups, and the SYP expression in P6w groups was higher than others. (4) The expressions of GluR2 consistent with the expression of SYP in IC. CONCLUSION The developmental changes of GluR2 and SYP expression in the rat IC may be involved in the development and plasticity of auditory center.
Animals ; Hypothalamus ; cytology ; metabolism ; Inferior Colliculi ; growth & development ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, AMPA ; metabolism ; Synapses ; metabolism ; Synaptophysin ; metabolism

OBJECTIVETo investigate the effect and its mechanism of Epimedium flavanoids (EF) in retarding aging with different systematic viewpoints.

METHODSHypothalamus, pituitary, adrenal and lymphocytes taken from 4-, 10-, 18-, 24-month old rats and from EF treated 24-month old rats were used to measure whole genome mRNA expression by gene array. Serum samples were used for metabonomic assay with high performance liquid chromatography. Using specific gene chip for NF-kappaB signaling pathway to detect the gene expression of the molecule related to that pathway in lymphocytes. Then, a neural network (NN) model was established upon the data obtained to quantitatively evaluate the degree of aging and the efficacy of drug intervention.

RESULTSGene expression of 199 genes showedan age-dependent pattern, most of which were reversed by EF, and the output of NN model showed that EF made the transcriptomics of 24-month old rats to 8-13 months. Seventeen metabolites among the 1,885 peaks detected were identified to have significant age-depending changes, and EF intervention reset the level of metabolites to a younger (18-month) level. The integral level of gene expression for NF-kappaB signaling pathway decreased significantly along with the increasing of age, and was significantly elevated by EF, NN model showed it approached to 10.5-month old.

CONCLUSIONPhenotype of aging at different levels demonstrates a common age-dependent trend; EF can reverse this age-dependent change at different levels in a synchronous manner.

Adrenal Glands ; drug effects ; growth & development ; metabolism ; Aging ; drug effects ; genetics ; metabolism ; Animals ; Chromatography, High Pressure Liquid ; Epimedium ; chemistry ; Flavonoids ; pharmacology ; Gene Expression Profiling ; Gene Expression Regulation, Developmental ; drug effects ; Hypothalamus ; drug effects ; growth & development ; metabolism ; Lymphocytes ; cytology ; drug effects ; metabolism ; Male ; NF-kappa B ; blood ; genetics ; metabolism ; Oligonucleotide Array Sequence Analysis ; methods ; Pituitary Gland ; drug effects ; growth & development ; metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Time Factors ; Transcription, Genetic ; drug effects

AIMTo explore the effect of cerebellar fastigial nuclei (FN)on lymphocyte function and the pathway mediating the effect.

METHODSKainic acid (KA) was microinjected into bilateral FN of rats to destroy neuronal bodies in the FN. On the eighth day after the surgery, lymphocyte percentage in the peripheral blood and level of sheep red blood cell(SRBC)-specific IgM antibody in the serum were measured by using blood corpuscle counter and enzyme-linked immunosorbent assay (ELISA), respectively.A technology of electrolytic lesion was used to destroy the projections of cerebellar FN neurons to hypothalamus in decussation of superior cerebellar peduncle(xscp).

RESULTSOn the eighth day after the microinjection of KA into the bilateral FN of rats, the Nissl-stained neuronal bodies in the FN disappeared and glia could proliferated within the damaged FN. In the nuclei close to FN, the interposed nuclei and the dentate nuclei, Nissl-stained neurons still could be seen. On the control cerebellar sections, in which FN was infused with saline, we could see the normal Nissl-stained neurons in the FN and the other two nuclei.On day 8 following the effective FN lesions, both the lymphocyte percentage in the peripheral blood and the level of anti-SRBC IgM antibody in the serum were significantly increased in comparison with those of control rats infused with saline in the FN. On the eighth day after electrolytic lesion of the fibres in xscp, the FN-hypothalamic projections were damaged and there were no visible BDA-positive endings in hypothalamus. Meanwhile, both the lymphocyte percentage in the peripheral blood and the level of anti-SRBC IgM antibody in the serum were remarkably enhanced relative to those of control rats with sham lesion of xscp.

CONCLUSIONThe electrolytic lesion of the FN-hypothalamic projections in xscp causes an enhancement of lymphocyte function similar to that of KA lesions of neuronal soma in the FN. These findings suggest that the cerebellohypothalamic projections participate in mediating the modulation of lymphocyte function by the cerebellum.

Animals ; Cerebellar Nuclei ; immunology ; injuries ; Female ; Hypothalamus ; immunology ; physiology ; Kainic Acid ; Lymphocyte Count ; Lymphocytes ; cytology ; immunology ; Male ; Neural Pathways ; immunology ; physiology ; Neuroimmunomodulation ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate whether hypertonic saline (HS) can induce the synthesis and release of glutamate in cultured hypothalamic astrocytes or C6 cell line.

METHODSAstrocytes were isolated, cultured, purified and identified from the hypothalamus of newborn rat (1 day). The astrocytes were randomly divided into five groups: isotonic (IS) and HS groups, astrocytes were incubated by IS and HS (320 mosM NaCl) medium, respectively, for 1, 3, 5, 10 or 15 min; carbenoxolone (CBX)+IS and CBX+HS groups, astrocytes were pre-treated with CBX (100 mmol/L) for 1 h at 37 degrees C in a 5% CO(2) / 95% atmosphere, then removed to IS and HS medium, respectively, for 1, 3, 5, 10 or 15 min; Ca(2+)+HS group, astrocytes were pre-incubated with Ca Ca(2+) (1,000 micromol/L) for 1 h at 37 degrees C in a 5% CO(2) / 95% atmosphere, followed by a wash with isotonic FBS/DMEM, and then removed to hypertonic saline for 1, 3, 5, 10 or 15 min. The media of five groups were collected to analyze the medium glutamate concentration with high performance liquid chromatography. The astrocytes were fixed and double immunofluorescent stained with anti-glial fibrillary acidic protein (GFAP) and anti-glutamate. The C6 cells were divided into four groups: IS, HS, CBX+IS and CBX+HS groups, and used for quantitative measurement of glutamate in cells by flow cytometry (FCM).

RESULTS(1) Anti-GFAP immunofluorescent signal revealed no significant difference among various time points in each group, or among the five groups. (2) The anti-glutamate immunofluorescent signal was increased in HS group and peaked at 5 min, and decreased and returned to the level of IS group at 15 min (P < 0.01 vs the 5 min of HS group). In CBX+HS group, the glutamate intensity was higher than that in CBX+IS and HS groups. (3) The medium glutamate concentration had no change after treatment with HS for 1 and 3 min, while increased markedly after treatment for 5 min to 15 min (P< 0.01 vs 1 min and 3 min). On the contrary, the medium glutamate concentrations in the CBX+HS or Ca(2+)+HS group were significant lower than that in the HS group (P < 0.01). (4) FCM showed HS and CBX+HS induced glutamate increase in C6 cells.

CONCLUSIONHS induced cultured rat hypothalamic astrocytes or C6 cells to synthesize and release glutamate; CBX could block glutamate release, but could not disrupt glutamate synthesis.

Analysis of Variance ; Animals ; Animals, Newborn ; Astrocytes ; drug effects ; metabolism ; Calcium ; pharmacology ; Carbenoxolone ; pharmacology ; Cells, Cultured ; Chromatography, High Pressure Liquid ; methods ; Flow Cytometry ; Gene Expression Regulation ; drug effects ; Glial Fibrillary Acidic Protein ; metabolism ; Glutamic Acid ; metabolism ; Hypothalamus ; cytology ; Rats ; Saline Solution, Hypertonic ; pharmacology ; Time Factors

OBJECTIVETo study the changes in the plasticity of the neurons and astrocytes in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus of rats exposed to a humid and hot environment.

METHODSThe rats were subjected to stimulation with a humid and hot environment for 120 min in a climate chamber (dry bulb temperature of 40.0-/+0.5 degrees C with relative humidity of 60-/+5%). During the exposure, the behavioral responses of the rats were observed, and the changes in the expressions of Fos and GFAP in the PVN and SON in response to the exposure evaluated using immunohistochemical ABC methods.

RESULTSExposure to a humid and hot environment caused restlessness and agitation in the rats, which showed increased respiratory frequency and scratching of the face with the forelimbs. Two rats died after the 120-min exposure. Significantly increased expressions of Fos and GFAP were detected in the PVN and SON following the exposure as compared with the control group.

CONCLUSIONThe neurons and astrocytes in the PVN and SON both participate in the regulation of responses to exposure to a humid and hot environment.

Animals ; Astrocytes ; cytology ; physiology ; Glial Fibrillary Acidic Protein ; analysis ; Hot Temperature ; Humidity ; Hypothalamus ; cytology ; metabolism ; Immunohistochemistry ; Male ; Neuronal Plasticity ; physiology ; Neurons ; cytology ; physiology ; Oncogene Proteins v-fos ; analysis ; Paraventricular Hypothalamic Nucleus ; cytology ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Supraoptic Nucleus ; cytology ; metabolism