To observe the glial reactions surrounding facial motor neurons following facial nerve anastomosis. At 1,7,21 and 60 d following facial nerve anastomosis, the recovery process of facial movement was observed, the glia...To observe the glial reactions surrounding facial motor neurons following facial nerve anastomosis. At 1,7,21 and 60 d following facial nerve anastomosis, the recovery process of facial movement was observed, the glial fibrillary acidic protein （GFAP） immunoreactivity was analyzed by a combined method of fluorescent retrograde tracing and immunofluorescent histochemical staining, and the uhrastructure of astrocytes were observed under a transmission electron microscope （TEM）, respectively. Postoperatively the function of facial muscles could not return to normal, often accompanied with hyperkinetic syndromes such as synkinesis at the late stage. Motor neurons in every facial subnucleus could be retrogradely labeled by fluoro-gold （FG）, and displayed an evident somatotopic organization. Normally there was a considerable number of GFAP-positive cells in nonnucleus regions but few inside the facial nucleus region. Postoperatively the GFAP immunoreactivity in the anastomotic side increased significantly, but gradually decreased at the late stage. The ultrastructure of astrocytes in our experiment showed that the sheet-like process of astrocytes invested and protected the injured facial motor neurons. The present study shows that reactive astrocytes undergo some characteristic changes during the process of facial nerve injury and regeneration. The plastic change at the late stage may be involved in the mechanism of synkinesis.展开更多
Previous studies have demonstrated that muscarinic, and nicotinic receptors increase free Ca2＋ levels in the facial nerve nucleus via various channels following facial nerve injury. However, intracellular Ca2＋ overl...Previous studies have demonstrated that muscarinic, and nicotinic receptors increase free Ca2＋ levels in the facial nerve nucleus via various channels following facial nerve injury. However, intracellular Ca2＋ overload can trigger either necrotic or apoptotic cell death. Gamma-aminobutyric acid （GABA）, an important inhibitory neurotransmitter in the central nervous system, exists in the facial nerve nucleus. It is assumed that GABA negatively regulates free Ca2＋ levels in the facial nerve nucleus. The present study investigated GABA type A （GABAA） receptor expression in the facial nerve nucleus in a rat model of facial nerve injury using immunohistochemistry and laser confocal microscopy, as well as the regulatory effects of GABAA receptor on nicotinic receptor response following facial nerve injury. Subunits α1, α3, α5, β1, β2, δ, and γ3 of GABAA receptors were expressed in the facial nerve nucleus following facial nerve injury. In addition, GABAA receptor expression significantly inhibited the increase in nicotinic receptor-mediated free Ca2＋ levels in the facial nerve nucleus following facial nerve injury in a concentration-dependent fashion. These results suggest that GABAA receptors exhibit negative effects on nicotinic receptor responses following facial nerve injury.展开更多
Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have...Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have been shown to negatively regulate free calcium ion levels in the facial nucleus by inhibiting nicotine receptors. The present study investigated the influence of GABAA, γ-aminobutyric acid B （GABAB） and C （GABAc） receptors on muscarinic receptors in rats with facial nerve injury by confocal laser microscopy. GABAA and GABAB receptors exhibited significant dose-dependent inhibitory effects on increased muscarinic receptor-mediated free calcium ion levels following facial nerve injury. Results showed that GABAA and GABAB receptors negatively regulate muscarinic receptor effects and interplay with cholinergic receptors to regulate free calcium ion levels for facial neural regeneration.展开更多
BACKGROUND： Previous studies have demonstrated that postsynaptic density protein-95 （PSD-95） is widely distributed in the central nervous system and is related to the development of the CNS and sensory signal trans...BACKGROUND： Previous studies have demonstrated that postsynaptic density protein-95 （PSD-95） is widely distributed in the central nervous system and is related to the development of the CNS and sensory signal transmission as well as acute or chronic nerve cell death following ischemic brain injury. OBJECTIVE： To semi-quantitatively determine the pathological changes of apoptotic facial neurons and the expression of PSD-95 in the facial nucleus following facial nerve injury of varying extents using immunohistochemical staining methods. DESIGN, TIME AND SETTING： Randomized, controlled animal experiments were performed in the Ultrasonic Institute of the Second Affiliated Hospital of Chongqing University of Medical Sciences from September to December 2007. MATERIALS： Sixty-five healthy, adult, Sprague-Dawley （SD） rats, both male and female, were used for this study. Rabbit anti-rat PSD-95 polyclonal antibody was purchased from Beijing Biosynthesis Biotechnology Co., Ltd. METHODS： SD rats were randomly assigned into a control group with five rats and three injured groups with 20 rats per group. Exposure, clamp and cut for bilateral facial nerve trunks were performed in the rats of the injury groups, and no injury was inflicted on the rats of the control group. MAIN OUTCOME MEASURES; The brainstems of all the rats were excised on days 1, 3, 7, and 14 post injury, and then the facial nuclei were stained with hematoxylin-eosin to observe any pathological changes due to apoptosis in facial neurons. PSD-95 expression in facial nuclei was detected by immunohistochemistry and the number of PSD-95 positive cells was counted under a light microscope. RESULTS： The expression of PSD-95 in the facial nucleus and morphology of the facial neuron within the exposure group had no obvious changes at various points in time tested （P 〉 0.05）. However, the expressions of PSD-95 in the facial nucleus of the clamp group and cut group increased on day 1 post injury （P 〈 0.05）, and showed further increase on d展开更多
BACKGROUND： Estrogen is neuroprotective effects such as breast carcinoma, endometria but long-term estrogen treatment can induce side cancer, and stroke. However, phytoestrogen is neuroprotective without these side e...BACKGROUND： Estrogen is neuroprotective effects such as breast carcinoma, endometria but long-term estrogen treatment can induce side cancer, and stroke. However, phytoestrogen is neuroprotective without these side effects. OBJECTIVE： To study the effects of Ginsenoside Rgl on facial neurons and brain-derived neurotrophic factor （BDNF） expression in the facial nucleus in ovariectomized rats. DESIGN, TIME AND SETTING： The randomized, controlled animal experiments were performed at the Ultrasonic Institute, Second Affiliated Hospital, Chongqing Medical University, China, from September 2007 to September 2008. MATERIALS： Ginsenoside Rgl （Sigma, USA）, rabbit anti-rat BDNF, Bcl-2, Bax antibodies, biotin-labeled goat anti-rabbit IgG （Boster, China）, and a TUNEL kit （Roche, Germany） were used in this study. METHODS： A total of 48 adult Sprague Dawley rats undergoing ovariectomy were randomly assigned into sham operation （n = 8）, model （n = 20）, and Ginsenoside Rgl （n = 20） groups. Facial nerve damage was induced by bilateral clamping of the facial nerve trunk. The bilateral facial nerve trunk was exposed in the sham operation group, with no clamping. Rats in the Ginsenoside Rgl group were intraperitoneally injected with 10 mg/kg per day Ginsenoside Rgl; other groups received 2 mL saline, once a day, for 14 days. MAIN OUTCOME MEASURES： Morphologic changes in neurons of the facial nucleus were observed following hematoxylin-eosin staining. Neuronal apoptosis was detected by TUNEL. Changes in ultrastructure of the facial nerve fibers were observed with a transmission electron microscope. Expression of BDNF, Bcl-2, and Bax protein was quantified by semiquantitative immunohistochemistry. RESULTS： At 3-14 days following facial nerve damage, Ginsenoside Rgl increased BDNF expression and the number of regenerated nerve fibers, and produced thicker myelin sheaths （P 〈 0.05）. Ginsenoside Rgl also gradually increased Bcl-2 protein expression and decreased Bax protein expression （P 展开更多
BACKGROUND： Calretinin and parvalbumin are members of the intracellular calcium binding protein family, which transform Ca^2＋ bioinformation into regulation of neuronal and neural network activities. OBJECTIVE： To ...BACKGROUND： Calretinin and parvalbumin are members of the intracellular calcium binding protein family, which transform Ca^2＋ bioinformation into regulation of neuronal and neural network activities. OBJECTIVE： To observe expression and co-expression of calretinin and parvalbumin in rat facial nucleus neurons . DESIGN, TIME AND SETTING： Neuronal morphology experiment was performed at the Research Laboratory of Applied Anatomy, Department Neurobiology and Anatomy, Xiangya Medical College of Central South University from August to October 2007. MATERIALS： Five healthy, adult Sprague Dawley rats were selected. Polyclonal rabbit-anti-parvalbumin and mouse-anti-calretinin were provided by Sigma, USA. METHODS： Rat brains were obtained and cut into coronal slices using a freezing microtome. Slices from the experimental group were immunofluorescent stained with polyclonal rabbit-anti-parvalbumin and mouse-anti-calretinin antibodies. The control group sections were stained with normal rabbit and mouse sera. MAIN OUTCOME MEASURES： Immunofluorescent double-staining was used to detect calretinin and parvalbumin expression. Nissl staining was utilized for facial nucleus localization and neuronal morphology analysis. RESULTS： The majority of facial motor neurons was polygon-shaped, and expressed calretinin and parvalbumin. The calretinin-immunopositive neurons also exhibited parvalbumin immunoreactivity, that is, calretinin and parvalbumin were co-expressed in the same neuron. CONCLUSION： Calretinin and parvalbumin were expressed in facial nucleus neurons, with varied distribution.展开更多
文摘To observe the glial reactions surrounding facial motor neurons following facial nerve anastomosis. At 1,7,21 and 60 d following facial nerve anastomosis, the recovery process of facial movement was observed, the glial fibrillary acidic protein （GFAP） immunoreactivity was analyzed by a combined method of fluorescent retrograde tracing and immunofluorescent histochemical staining, and the uhrastructure of astrocytes were observed under a transmission electron microscope （TEM）, respectively. Postoperatively the function of facial muscles could not return to normal, often accompanied with hyperkinetic syndromes such as synkinesis at the late stage. Motor neurons in every facial subnucleus could be retrogradely labeled by fluoro-gold （FG）, and displayed an evident somatotopic organization. Normally there was a considerable number of GFAP-positive cells in nonnucleus regions but few inside the facial nucleus region. Postoperatively the GFAP immunoreactivity in the anastomotic side increased significantly, but gradually decreased at the late stage. The ultrastructure of astrocytes in our experiment showed that the sheet-like process of astrocytes invested and protected the injured facial motor neurons. The present study shows that reactive astrocytes undergo some characteristic changes during the process of facial nerve injury and regeneration. The plastic change at the late stage may be involved in the mechanism of synkinesis.
基金a Grant from the Youth Research Foundation of Qingdao University,No.2007
文摘Previous studies have demonstrated that muscarinic, and nicotinic receptors increase free Ca2＋ levels in the facial nerve nucleus via various channels following facial nerve injury. However, intracellular Ca2＋ overload can trigger either necrotic or apoptotic cell death. Gamma-aminobutyric acid （GABA）, an important inhibitory neurotransmitter in the central nervous system, exists in the facial nerve nucleus. It is assumed that GABA negatively regulates free Ca2＋ levels in the facial nerve nucleus. The present study investigated GABA type A （GABAA） receptor expression in the facial nerve nucleus in a rat model of facial nerve injury using immunohistochemistry and laser confocal microscopy, as well as the regulatory effects of GABAA receptor on nicotinic receptor response following facial nerve injury. Subunits α1, α3, α5, β1, β2, δ, and γ3 of GABAA receptors were expressed in the facial nerve nucleus following facial nerve injury. In addition, GABAA receptor expression significantly inhibited the increase in nicotinic receptor-mediated free Ca2＋ levels in the facial nerve nucleus following facial nerve injury in a concentration-dependent fashion. These results suggest that GABAA receptors exhibit negative effects on nicotinic receptor responses following facial nerve injury.
基金the Youth Research Foundation of Qingdao University, No. 2007
文摘Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have been shown to negatively regulate free calcium ion levels in the facial nucleus by inhibiting nicotine receptors. The present study investigated the influence of GABAA, γ-aminobutyric acid B （GABAB） and C （GABAc） receptors on muscarinic receptors in rats with facial nerve injury by confocal laser microscopy. GABAA and GABAB receptors exhibited significant dose-dependent inhibitory effects on increased muscarinic receptor-mediated free calcium ion levels following facial nerve injury. Results showed that GABAA and GABAB receptors negatively regulate muscarinic receptor effects and interplay with cholinergic receptors to regulate free calcium ion levels for facial neural regeneration.
文摘BACKGROUND： Previous studies have demonstrated that postsynaptic density protein-95 （PSD-95） is widely distributed in the central nervous system and is related to the development of the CNS and sensory signal transmission as well as acute or chronic nerve cell death following ischemic brain injury. OBJECTIVE： To semi-quantitatively determine the pathological changes of apoptotic facial neurons and the expression of PSD-95 in the facial nucleus following facial nerve injury of varying extents using immunohistochemical staining methods. DESIGN, TIME AND SETTING： Randomized, controlled animal experiments were performed in the Ultrasonic Institute of the Second Affiliated Hospital of Chongqing University of Medical Sciences from September to December 2007. MATERIALS： Sixty-five healthy, adult, Sprague-Dawley （SD） rats, both male and female, were used for this study. Rabbit anti-rat PSD-95 polyclonal antibody was purchased from Beijing Biosynthesis Biotechnology Co., Ltd. METHODS： SD rats were randomly assigned into a control group with five rats and three injured groups with 20 rats per group. Exposure, clamp and cut for bilateral facial nerve trunks were performed in the rats of the injury groups, and no injury was inflicted on the rats of the control group. MAIN OUTCOME MEASURES; The brainstems of all the rats were excised on days 1, 3, 7, and 14 post injury, and then the facial nuclei were stained with hematoxylin-eosin to observe any pathological changes due to apoptosis in facial neurons. PSD-95 expression in facial nuclei was detected by immunohistochemistry and the number of PSD-95 positive cells was counted under a light microscope. RESULTS： The expression of PSD-95 in the facial nucleus and morphology of the facial neuron within the exposure group had no obvious changes at various points in time tested （P 〉 0.05）. However, the expressions of PSD-95 in the facial nucleus of the clamp group and cut group increased on day 1 post injury （P 〈 0.05）, and showed further increase on d
文摘BACKGROUND： Estrogen is neuroprotective effects such as breast carcinoma, endometria but long-term estrogen treatment can induce side cancer, and stroke. However, phytoestrogen is neuroprotective without these side effects. OBJECTIVE： To study the effects of Ginsenoside Rgl on facial neurons and brain-derived neurotrophic factor （BDNF） expression in the facial nucleus in ovariectomized rats. DESIGN, TIME AND SETTING： The randomized, controlled animal experiments were performed at the Ultrasonic Institute, Second Affiliated Hospital, Chongqing Medical University, China, from September 2007 to September 2008. MATERIALS： Ginsenoside Rgl （Sigma, USA）, rabbit anti-rat BDNF, Bcl-2, Bax antibodies, biotin-labeled goat anti-rabbit IgG （Boster, China）, and a TUNEL kit （Roche, Germany） were used in this study. METHODS： A total of 48 adult Sprague Dawley rats undergoing ovariectomy were randomly assigned into sham operation （n = 8）, model （n = 20）, and Ginsenoside Rgl （n = 20） groups. Facial nerve damage was induced by bilateral clamping of the facial nerve trunk. The bilateral facial nerve trunk was exposed in the sham operation group, with no clamping. Rats in the Ginsenoside Rgl group were intraperitoneally injected with 10 mg/kg per day Ginsenoside Rgl; other groups received 2 mL saline, once a day, for 14 days. MAIN OUTCOME MEASURES： Morphologic changes in neurons of the facial nucleus were observed following hematoxylin-eosin staining. Neuronal apoptosis was detected by TUNEL. Changes in ultrastructure of the facial nerve fibers were observed with a transmission electron microscope. Expression of BDNF, Bcl-2, and Bax protein was quantified by semiquantitative immunohistochemistry. RESULTS： At 3-14 days following facial nerve damage, Ginsenoside Rgl increased BDNF expression and the number of regenerated nerve fibers, and produced thicker myelin sheaths （P 〈 0.05）. Ginsenoside Rgl also gradually increased Bcl-2 protein expression and decreased Bax protein expression （P
基金the Scientific Research Program of Hunan Provincial Health Department, No. C2007038the Key Scientific Research Program of Xiangnan College, No. 2007Z011
文摘BACKGROUND： Calretinin and parvalbumin are members of the intracellular calcium binding protein family, which transform Ca^2＋ bioinformation into regulation of neuronal and neural network activities. OBJECTIVE： To observe expression and co-expression of calretinin and parvalbumin in rat facial nucleus neurons . DESIGN, TIME AND SETTING： Neuronal morphology experiment was performed at the Research Laboratory of Applied Anatomy, Department Neurobiology and Anatomy, Xiangya Medical College of Central South University from August to October 2007. MATERIALS： Five healthy, adult Sprague Dawley rats were selected. Polyclonal rabbit-anti-parvalbumin and mouse-anti-calretinin were provided by Sigma, USA. METHODS： Rat brains were obtained and cut into coronal slices using a freezing microtome. Slices from the experimental group were immunofluorescent stained with polyclonal rabbit-anti-parvalbumin and mouse-anti-calretinin antibodies. The control group sections were stained with normal rabbit and mouse sera. MAIN OUTCOME MEASURES： Immunofluorescent double-staining was used to detect calretinin and parvalbumin expression. Nissl staining was utilized for facial nucleus localization and neuronal morphology analysis. RESULTS： The majority of facial motor neurons was polygon-shaped, and expressed calretinin and parvalbumin. The calretinin-immunopositive neurons also exhibited parvalbumin immunoreactivity, that is, calretinin and parvalbumin were co-expressed in the same neuron. CONCLUSION： Calretinin and parvalbumin were expressed in facial nucleus neurons, with varied distribution.
