In the present study, we hypothesized that 5-hydroxymethyl-2-furfural could attenuate ischemic brain damage by reducing oxidative injury. Thus, mice were subjected to bilateral common carotid artery occlusion to estab...In the present study, we hypothesized that 5-hydroxymethyl-2-furfural could attenuate ischemic brain damage by reducing oxidative injury. Thus, mice were subjected to bilateral common carotid artery occlusion to establish a model of permanent forebrain ischemia. The mice were intraperitoneally injected with 5-hydroxymethyl-2-furfura130 minutes before ischemia or 5 minutes after ischemia. The survival time of mice injected with 5-hydroxymethyl-2-furfural was longer compared with untreated mice. The mice subjected to ischemia for 30 minutes and reperfusion for 5 minutes were intraperitoneally injected with 5-hydroxymethyl-2-furfural 5 minutes prior to reperfusion, which increased superoxide dismutase content and reduced malondialdehyde content, similar to the effects of Edaravone, a hydroxyl radical scavenger used for the treatment of stroke. These findings indicate that intraperitoneal injection of 5-hydroxymethyl-2-furfural can prolong the survival of mice with permanent forebrain ischemia. This outcome may be mediated by its antioxidative effects.展开更多
In the present study we injected colchicine into the lateral ventricle of Sprague-Dawley rats to investigate the effects of colchicine on the number of different-type neurons in the basal forebrain and to search for n...In the present study we injected colchicine into the lateral ventricle of Sprague-Dawley rats to investigate the effects of colchicine on the number of different-type neurons in the basal forebrain and to search for neurons resistant to injury. After colchicine injection, the number of nestin^＋ cholinergic neurons was decreased at 1 day, but increased at 3 days and peaked at 14-28 days. The quantity of nestincholinergic neurons, parvalbumin-positive neurons and choline acetyl transferase-positive neurons decreased gradually. Our results indicate that nestin^＋ cholinergic neurons possess better tolerance to colchicine-induced neurotoxicity.展开更多
Recent evidence exists that glucose transporter 3（GLUT3） plays an important role in the energy metabolism in the brain.Most previous studies have been conducted using focal or hypoxic ischemia models and have focuse...Recent evidence exists that glucose transporter 3（GLUT3） plays an important role in the energy metabolism in the brain.Most previous studies have been conducted using focal or hypoxic ischemia models and have focused on changes in GLUT3 expression based on protein and m RNA levels rather than tissue levels.In the present study,we observed change in GLUT3 immunoreactivity in the adult gerbil hippocampus at various time points after 5 minutes of transient forebrain ischemia.In the sham-operated group,GLUT3 immunoreactivity in the hippocampal CA1 region was weak,in the pyramidal cells of the CA1 region increased in a time-dependent fashion 24 hours after ischemia,and in the hippocampal CA1 region decreased significantly between 2 and 5 days after ischemia,with high level of GLUT3 immunoreactivity observed in the CA1 region 10 days after ischemia.In a double immunofluorescence study using GLUT3 and glial-fibrillary acidic protein（GFAP）,we observed strong GLUT3 immunoreactivity in the astrocytes.GLUT3 immunoreactivity increased after ischemia and peaked 7 days in the dentate gyrus after ischemia/reperfusion.In a double immunofluorescence study using GLUT3 and doublecortin（DCX）,we observed low level of GLUT3 immunoreactivity in the differentiated neuroblasts of the subgranular zone of the dentate gyrus after ischemia.GLUT3 immunoreactivity in the sham-operated group was mainly detected in the subgranular zone of the dentate gyrus.These results suggest that the increase in GLUT3 immunoreactivity may be a compensatory mechanism to modulate glucose level in the hippocampal CA1 region and to promote adult neurogenesis in the dentate gyrus.展开更多
Hypothermia is an important protective strategy against global cerebral ischemia following cardiac arrest.However,the mechanisms of hypothermia underlying the changes in different regions and connections of the brain ...Hypothermia is an important protective strategy against global cerebral ischemia following cardiac arrest.However,the mechanisms of hypothermia underlying the changes in different regions and connections of the brain have not been fully elucidated.This study aims to identify the metabolic nodes and connection integrity of specific brain regions in rats with global cerebral ischemia that are most affected by hypothermia treatment.18F-fluorodeoxyglucose positron emission tomography was used to quantitatively determine glucose metabolism in different brain regions in a rat model of global cerebral ischemia established at 31–33℃.Diffusion tensor imaging was also used to reconstruct and explore the brain connections involved.The results showed that,compared with the model rats established at 37–37.5℃,the rat models of global cerebral ischemia established at 31–33℃had smaller hypometabolic regions in the thalamus and primary sensory areas and sustained no obvious thalamic injury.Hypothermia selectively preserved the integrity of the anterior forebrain mesocircuit,exhibiting protective effects on the brain during the global cerebral ischemia.The study was approved by the Institutional Animal Care and Use Committee at Capital Medical University(approval No.XW-AD318-97-019)on December 15,2019.展开更多
~[he cingulum, a long neural tract extending from the orbitof- rontal cortex to the medial temporal lobe, obtains cholinergic innervation from three cholinergic nuclei in the basal fore- brain （the nucleus basalis of...~[he cingulum, a long neural tract extending from the orbitof- rontal cortex to the medial temporal lobe, obtains cholinergic innervation from three cholinergic nuclei in the basal fore- brain （the nucleus basalis of Meynert [Ch 4], the medial septal nucleus [Ch 1 ], and the vertical nucleus of the diagonal band [Ch 2]）, and is the passage of the medial cholinergic pathway which supplies cholinergic innervation from the basal forebrain to the cerebral cortex （Folstein et al., 1975; Selden et al., 1998; Lucas-Meunier et al., 2003）. Therefore, it is important for cog- nition, especially memory function （Selden et al., 1998）.展开更多
BACKGROUND： Interferon-gamma （IFN-γ） can make neurons in basal forebrain and septal nuclei differentiate into cholinergic neurons by treating the cells in cerebral cortex of newborn rats, without the inhibition fr...BACKGROUND： Interferon-gamma （IFN-γ） can make neurons in basal forebrain and septal nuclei differentiate into cholinergic neurons by treating the cells in cerebral cortex of newborn rats, without the inhibition from IFN-γ antibody. The important effect of IFN-γ on the development and differentiation of neurons has been found by some scholars. OBJ EClIVE：To investigate whether IFN-γ has differentiational effect on cholinergic neurons in basal forebrain and septal nuclei, and make clear that the increased number of cholinergic neurons is resulted by cell differentiation or cell proliferation. DESIGN ： Controlled observation trial SETTING： Department of Cell Biology, Medical School, Beijing University MATERIALS： Sixty-eight female Wistar rats at embryonic 16 days, weighing 250 to 350 g, were enrolled in this study, and they were provided by the Experimental Animal Center, Medical School, Beijing University. IFN-γ was the product of Gibco Company. METHODS： This study was carried out in the Department of Cell Biology, Medical School, Beijing University and Daheng Image Company of Chinese Academy of Sciences during September 1995 to December 2002. The female Wistar rats at embryonic 16 days were sacrificed, and their fetuses were taken out. Primary culture of the isolated basal forebrain and septal nuclei was performed. The cultured nerve cells were assigned into 3 groups： control group （nothing added）, IFN-γ group（1×10^5 U/L interferon）, IFN-γ＋ IFN-γ antibody group （1 ×10^5 U/L IFN-γ ＋ IFN-γ antibody）. The specific marker enzyme （choline acetyl transferase） of cholinergic neuron was stained with immunohistochemical method. Choline acetyl transferase positive cells were counted, and ^14C-acetyl CoA was used as substrate to detect the activity of choline acetyl transferase, so as to reflect the differentiational effect of IFN-γ on cholinergic neuron in basal forebrain and septal nuclei. Flow cytometry was used to analyze cell circle and detect the proliferation of nerve cells. Nerve cells were marked with MAP2 and counted to evaluate the neuronal proliferation in basal forebrain and septal nuclei. MAIN OUTCOME MEASURES： Effect of interferon-γ on the number and activity of choline acetyl transferase-positive ceils in basal forebrain and septal nuclei as well as the effect on neuronal proliferation. RESULTS ： ① Nerve cells in the basal forebrain and septal nuclei of IFN-γ group grew well compared with control group.②The differentiation of cholinergic neurons： The number and activity of choline acetyl transferase positive cells in IFN-γ group were significantly higher than those in the control group [（49.30 ±4.92） /100 cells vs （7.50±1.58） /100 cells; （2 049.00±12.30） min^-1 vs （1 227.30±12.59） min^-1, p 〈 0.01], while there was no significant difference in the number and activity of choline acetyl transferase positive cells between IFN-γ ＋ IFN-γ antibody group and control group（P 〉 0.05）. ③The proliferation of cholinergic neurons： Cell percentage was 17.2% and 19.8% at S-stage, 6.2% and 6.1% at G2＋M stage in the control group and IFN-γ group respectively, without significant difference （P 〉 0.05）. CONCLUSION ： IFN-γ does not promote the neuronal proliferation in basal forebrain and septal nuclei, and the increased expression of cholinergic neurons is not resulted by the increase in the number of neurons, but its differentiation.展开更多
Artemisia capillaris Thunberg is a medicinal plant used as a traditional medicine in many cultures. It is an effective remedy for liver problems including hepatitis. Recent pharmacological reports have indicated that ...Artemisia capillaris Thunberg is a medicinal plant used as a traditional medicine in many cultures. It is an effective remedy for liver problems including hepatitis. Recent pharmacological reports have indicated that Artemisia species can exert various neurological effects. Previously, we reported a memory-enhancing effect of Artemisia species. However, the mechanisms underlying the neuroprotective effect of A. capillaris(AC) are still unknown. In the present study, we investigated the effect of an ethanol extract of AC on ischemic brain injury in a mouse model of transient forebrain ischemia. The mice were treated with AC for seven days, beginning one day before induction of transient forebrain ischemia. Behavioral deficits were investigated using the Y-maze. Nissl and Fluoro-jade B staining were used to indicate the site of injury. To determine the underlying mechanisms for the drug, we measured acetylcholinesterase activity. AC(200 mg·kg-1) treatment reduced transient forebrain ischemia-induced neuronal cell death in the hippocampal CA1 region. The AC-treated group also showed significant amelioration in the spontaneous alternation of the Y-maze test performance, compared to that in the untreated transient forebrain ischemia group. Moreover, AC treatment showed a concentration-dependent inhibitory effect on acetylcholinesterase activity in vitro. Finally, the effect of AC on forebrain ischemia was blocked by mecamylamine, a nonselective nicotinic acetylcholine receptor antagonist. Our results suggested that in a model of forebrain ischemia, AC protected against neuronal death through the activation of nicotinic acetylcholine receptors.展开更多
The levels of DNA polymerase α,δ,ε were examined in the neonatal mouse forebrains andspleens.The levels of DNA polymerase α were determined by the difference of polymerase activity in theabsence and the presence ...The levels of DNA polymerase α,δ,ε were examined in the neonatal mouse forebrains andspleens.The levels of DNA polymerase α were determined by the difference of polymerase activity in theabsence and the presence of α specific inhibitor,BuPdGTP,or its monoclonal antibody.The levels of DNApolymerase δ were determined in H · A fractions after separating it from the other two enzymes.The levelsof DNA polymerase ε were identified in H · A fractions by the use of α-monoclonal antibody or BuPdGTP.Results showed that in the mouse forebrain DNA polymerase α,δ,ε activities are the highest before birth,decline sharply following birth and are very low on the 8th day and hardly detectable on the 17th day;as forthe mouse spleen,however,DNA polymerase α,δ,ε activities are the lowest at birth,increase rapidly afterbirth and reach their maxima on the 8th day and then decline gradually but remain in higher levels.Theseresults not only prove that DNA polymerase α and δ take part in cell DNA replication but also suggest thatDNA polymerase ε is involved in DNA replication.展开更多
Therapeutic intervention for spinal cord injury is limited,with many approaches relying on strengthening the remaining substrate and driving recovery through rehabilitative training.As compared with learning novel com...Therapeutic intervention for spinal cord injury is limited,with many approaches relying on strengthening the remaining substrate and driving recovery through rehabilitative training.As compared with learning novel compensatory strategies,rehabilitation focuses on resto ring movements lost to injury.Whether rehabilitation of previously learned movements after spinal cord injury requires the molecular mechanisms of motor learning,or if it engages previously trained motor circuits without requiring novel learning remains an open question.In this study,mice we re randomly assigned to receive intrape ritoneal injection with the pan-nicotinic,non-competitive antagonist mecamylamine and the nicotinicα7 subunit selective antagonist methyllycaconitine citrate salt or vehicle(normal saline)prior to motor learning assays,then randomly reassigned after motor learning for rehabilitation study post-injury.Ce rvical spinal co rd dorsal column lesion was used as a model of in complete injury.Results of this study showed that nicotinic acetylcholine signaling was required for motor learning of the single pellet-reaching task but it was dispensable for the rehabilitation of the same task after injury.Our findings indicate that critical diffe rences exist between the molecular mechanisms supporting compensatory motor learning strategies and the restoration of behavior lost to spinal cord injury.展开更多
基金supported by the National Basic Research Program of China (973 Program),No.2003CB517104the National Natural Science Foundation of China,No.30973513+3 种基金Beijing Municipal Science and Technology Program,No.D0206001043191the Natural Science Foundation of Beijing,No.7112061Beijing Key Foundation of Traditional Chinese Medicine,No.KJTS2011-04Beijing Health and Technical Personal of High-Level Plan,No.2009-3-66
文摘In the present study, we hypothesized that 5-hydroxymethyl-2-furfural could attenuate ischemic brain damage by reducing oxidative injury. Thus, mice were subjected to bilateral common carotid artery occlusion to establish a model of permanent forebrain ischemia. The mice were intraperitoneally injected with 5-hydroxymethyl-2-furfura130 minutes before ischemia or 5 minutes after ischemia. The survival time of mice injected with 5-hydroxymethyl-2-furfural was longer compared with untreated mice. The mice subjected to ischemia for 30 minutes and reperfusion for 5 minutes were intraperitoneally injected with 5-hydroxymethyl-2-furfural 5 minutes prior to reperfusion, which increased superoxide dismutase content and reduced malondialdehyde content, similar to the effects of Edaravone, a hydroxyl radical scavenger used for the treatment of stroke. These findings indicate that intraperitoneal injection of 5-hydroxymethyl-2-furfural can prolong the survival of mice with permanent forebrain ischemia. This outcome may be mediated by its antioxidative effects.
基金the National Natural Science Foundation of China,No. 30700436
文摘In the present study we injected colchicine into the lateral ventricle of Sprague-Dawley rats to investigate the effects of colchicine on the number of different-type neurons in the basal forebrain and to search for neurons resistant to injury. After colchicine injection, the number of nestin^＋ cholinergic neurons was decreased at 1 day, but increased at 3 days and peaked at 14-28 days. The quantity of nestincholinergic neurons, parvalbumin-positive neurons and choline acetyl transferase-positive neurons decreased gradually. Our results indicate that nestin^＋ cholinergic neurons possess better tolerance to colchicine-induced neurotoxicity.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education,No.NRF-2013R1A1A2059364,NRF-2015R1D1A3A01020635)by 2013 Research Grant from Kangwon National Universitypartially supported by the Research Institute for Veterinary Science,Seoul National University
文摘Recent evidence exists that glucose transporter 3（GLUT3） plays an important role in the energy metabolism in the brain.Most previous studies have been conducted using focal or hypoxic ischemia models and have focused on changes in GLUT3 expression based on protein and m RNA levels rather than tissue levels.In the present study,we observed change in GLUT3 immunoreactivity in the adult gerbil hippocampus at various time points after 5 minutes of transient forebrain ischemia.In the sham-operated group,GLUT3 immunoreactivity in the hippocampal CA1 region was weak,in the pyramidal cells of the CA1 region increased in a time-dependent fashion 24 hours after ischemia,and in the hippocampal CA1 region decreased significantly between 2 and 5 days after ischemia,with high level of GLUT3 immunoreactivity observed in the CA1 region 10 days after ischemia.In a double immunofluorescence study using GLUT3 and glial-fibrillary acidic protein（GFAP）,we observed strong GLUT3 immunoreactivity in the astrocytes.GLUT3 immunoreactivity increased after ischemia and peaked 7 days in the dentate gyrus after ischemia/reperfusion.In a double immunofluorescence study using GLUT3 and doublecortin（DCX）,we observed low level of GLUT3 immunoreactivity in the differentiated neuroblasts of the subgranular zone of the dentate gyrus after ischemia.GLUT3 immunoreactivity in the sham-operated group was mainly detected in the subgranular zone of the dentate gyrus.These results suggest that the increase in GLUT3 immunoreactivity may be a compensatory mechanism to modulate glucose level in the hippocampal CA1 region and to promote adult neurogenesis in the dentate gyrus.
基金supported by Beijing Municipal Health Commission of China,No.Jing2019-2(to TLW)。
文摘Hypothermia is an important protective strategy against global cerebral ischemia following cardiac arrest.However,the mechanisms of hypothermia underlying the changes in different regions and connections of the brain have not been fully elucidated.This study aims to identify the metabolic nodes and connection integrity of specific brain regions in rats with global cerebral ischemia that are most affected by hypothermia treatment.18F-fluorodeoxyglucose positron emission tomography was used to quantitatively determine glucose metabolism in different brain regions in a rat model of global cerebral ischemia established at 31–33℃.Diffusion tensor imaging was also used to reconstruct and explore the brain connections involved.The results showed that,compared with the model rats established at 37–37.5℃,the rat models of global cerebral ischemia established at 31–33℃had smaller hypometabolic regions in the thalamus and primary sensory areas and sustained no obvious thalamic injury.Hypothermia selectively preserved the integrity of the anterior forebrain mesocircuit,exhibiting protective effects on the brain during the global cerebral ischemia.The study was approved by the Institutional Animal Care and Use Committee at Capital Medical University(approval No.XW-AD318-97-019)on December 15,2019.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,No.2015R1D1A4A01020385
文摘~[he cingulum, a long neural tract extending from the orbitof- rontal cortex to the medial temporal lobe, obtains cholinergic innervation from three cholinergic nuclei in the basal fore- brain （the nucleus basalis of Meynert [Ch 4], the medial septal nucleus [Ch 1 ], and the vertical nucleus of the diagonal band [Ch 2]）, and is the passage of the medial cholinergic pathway which supplies cholinergic innervation from the basal forebrain to the cerebral cortex （Folstein et al., 1975; Selden et al., 1998; Lucas-Meunier et al., 2003）. Therefore, it is important for cog- nition, especially memory function （Selden et al., 1998）.
基金the National Nat-ural Science Foundation of Chi-na, No.39570249
文摘BACKGROUND： Interferon-gamma （IFN-γ） can make neurons in basal forebrain and septal nuclei differentiate into cholinergic neurons by treating the cells in cerebral cortex of newborn rats, without the inhibition from IFN-γ antibody. The important effect of IFN-γ on the development and differentiation of neurons has been found by some scholars. OBJ EClIVE：To investigate whether IFN-γ has differentiational effect on cholinergic neurons in basal forebrain and septal nuclei, and make clear that the increased number of cholinergic neurons is resulted by cell differentiation or cell proliferation. DESIGN ： Controlled observation trial SETTING： Department of Cell Biology, Medical School, Beijing University MATERIALS： Sixty-eight female Wistar rats at embryonic 16 days, weighing 250 to 350 g, were enrolled in this study, and they were provided by the Experimental Animal Center, Medical School, Beijing University. IFN-γ was the product of Gibco Company. METHODS： This study was carried out in the Department of Cell Biology, Medical School, Beijing University and Daheng Image Company of Chinese Academy of Sciences during September 1995 to December 2002. The female Wistar rats at embryonic 16 days were sacrificed, and their fetuses were taken out. Primary culture of the isolated basal forebrain and septal nuclei was performed. The cultured nerve cells were assigned into 3 groups： control group （nothing added）, IFN-γ group（1×10^5 U/L interferon）, IFN-γ＋ IFN-γ antibody group （1 ×10^5 U/L IFN-γ ＋ IFN-γ antibody）. The specific marker enzyme （choline acetyl transferase） of cholinergic neuron was stained with immunohistochemical method. Choline acetyl transferase positive cells were counted, and ^14C-acetyl CoA was used as substrate to detect the activity of choline acetyl transferase, so as to reflect the differentiational effect of IFN-γ on cholinergic neuron in basal forebrain and septal nuclei. Flow cytometry was used to analyze cell circle and detect the proliferation of nerve cells. Nerve cells were marked with MAP2 and counted to evaluate the neuronal proliferation in basal forebrain and septal nuclei. MAIN OUTCOME MEASURES： Effect of interferon-γ on the number and activity of choline acetyl transferase-positive ceils in basal forebrain and septal nuclei as well as the effect on neuronal proliferation. RESULTS ： ① Nerve cells in the basal forebrain and septal nuclei of IFN-γ group grew well compared with control group.②The differentiation of cholinergic neurons： The number and activity of choline acetyl transferase positive cells in IFN-γ group were significantly higher than those in the control group [（49.30 ±4.92） /100 cells vs （7.50±1.58） /100 cells; （2 049.00±12.30） min^-1 vs （1 227.30±12.59） min^-1, p 〈 0.01], while there was no significant difference in the number and activity of choline acetyl transferase positive cells between IFN-γ ＋ IFN-γ antibody group and control group（P 〉 0.05）. ③The proliferation of cholinergic neurons： Cell percentage was 17.2% and 19.8% at S-stage, 6.2% and 6.1% at G2＋M stage in the control group and IFN-γ group respectively, without significant difference （P 〉 0.05）. CONCLUSION ： IFN-γ does not promote the neuronal proliferation in basal forebrain and septal nuclei, and the increased expression of cholinergic neurons is not resulted by the increase in the number of neurons, but its differentiation.
基金supported by Dong-A University Research Supporting Program
文摘Artemisia capillaris Thunberg is a medicinal plant used as a traditional medicine in many cultures. It is an effective remedy for liver problems including hepatitis. Recent pharmacological reports have indicated that Artemisia species can exert various neurological effects. Previously, we reported a memory-enhancing effect of Artemisia species. However, the mechanisms underlying the neuroprotective effect of A. capillaris(AC) are still unknown. In the present study, we investigated the effect of an ethanol extract of AC on ischemic brain injury in a mouse model of transient forebrain ischemia. The mice were treated with AC for seven days, beginning one day before induction of transient forebrain ischemia. Behavioral deficits were investigated using the Y-maze. Nissl and Fluoro-jade B staining were used to indicate the site of injury. To determine the underlying mechanisms for the drug, we measured acetylcholinesterase activity. AC(200 mg·kg-1) treatment reduced transient forebrain ischemia-induced neuronal cell death in the hippocampal CA1 region. The AC-treated group also showed significant amelioration in the spontaneous alternation of the Y-maze test performance, compared to that in the untreated transient forebrain ischemia group. Moreover, AC treatment showed a concentration-dependent inhibitory effect on acetylcholinesterase activity in vitro. Finally, the effect of AC on forebrain ischemia was blocked by mecamylamine, a nonselective nicotinic acetylcholine receptor antagonist. Our results suggested that in a model of forebrain ischemia, AC protected against neuronal death through the activation of nicotinic acetylcholine receptors.
基金the Basic Research Grant form Chinese Academy of Sciences
文摘The levels of DNA polymerase α,δ,ε were examined in the neonatal mouse forebrains andspleens.The levels of DNA polymerase α were determined by the difference of polymerase activity in theabsence and the presence of α specific inhibitor,BuPdGTP,or its monoclonal antibody.The levels of DNApolymerase δ were determined in H · A fractions after separating it from the other two enzymes.The levelsof DNA polymerase ε were identified in H · A fractions by the use of α-monoclonal antibody or BuPdGTP.Results showed that in the mouse forebrain DNA polymerase α,δ,ε activities are the highest before birth,decline sharply following birth and are very low on the 8th day and hardly detectable on the 17th day;as forthe mouse spleen,however,DNA polymerase α,δ,ε activities are the lowest at birth,increase rapidly afterbirth and reach their maxima on the 8th day and then decline gradually but remain in higher levels.Theseresults not only prove that DNA polymerase α and δ take part in cell DNA replication but also suggest thatDNA polymerase ε is involved in DNA replication.
基金supported by the Burke Foundation and the National Institutes of Health Common Fund,No.DP2 NS106663(to ERH)the New York State Department of Health Spinal Cord Injury Research Board Postdoctoral Fellowship,No.C32633GG(to YL)。
文摘Therapeutic intervention for spinal cord injury is limited,with many approaches relying on strengthening the remaining substrate and driving recovery through rehabilitative training.As compared with learning novel compensatory strategies,rehabilitation focuses on resto ring movements lost to injury.Whether rehabilitation of previously learned movements after spinal cord injury requires the molecular mechanisms of motor learning,or if it engages previously trained motor circuits without requiring novel learning remains an open question.In this study,mice we re randomly assigned to receive intrape ritoneal injection with the pan-nicotinic,non-competitive antagonist mecamylamine and the nicotinicα7 subunit selective antagonist methyllycaconitine citrate salt or vehicle(normal saline)prior to motor learning assays,then randomly reassigned after motor learning for rehabilitation study post-injury.Ce rvical spinal co rd dorsal column lesion was used as a model of in complete injury.Results of this study showed that nicotinic acetylcholine signaling was required for motor learning of the single pellet-reaching task but it was dispensable for the rehabilitation of the same task after injury.Our findings indicate that critical diffe rences exist between the molecular mechanisms supporting compensatory motor learning strategies and the restoration of behavior lost to spinal cord injury.
