OBJECTIVE: This study investigated the antidepression mechanisms of Xiaoyaosan (XYS), a classic Chinese prescription, from the perspective of energy metabolism in the brain and intestinal tissues. METHODS: Chronic unpredictable mild stress model-a classic depression rat model-was established. Effects of XYS on behaviors and gastrointestinal motility of depressed rats were investigated. Effects of XYS on energetic charge (EC), adenosine triphosphate-related enzymes, and key enzymes of energy metabolism in both hippocampus and jejunum tissues of depressed rats were investigated using high-performance liquid chromatography, biochemical analysis, and real-time quantitative polymerase chain reaction, respectively. Spearman correlation analysis was conducted to construct a correlation network of "behavior-brain energy metabolism-intestinal energy metabolism" of depression. RESULTS: XYS significantly reduced the abnormal behaviors that observed in depressed rats and increased the EC and the activity of Na⁺-K⁺-adenosine triphosphatase (ATPase) and Ca²⁺-Mg²⁺-ATPase in hippocampus and jejunum tissues of depressed rats. XYS restored the key energetic pathways that had been interrupted by depression, including glycolysis, tricarboxylic acid cycle, and oxidative phosphorylation. Furthermore, XYS exhibited antidepressive effects in terms of regulating energy metabolism in tissues of both brain and intestine. CONCLUSION XYS significantly corrected the disturbances in EC and energy metabolism-related enzymes of both brain and intestinal tissues, alleviating both core and concomitant symptoms of depression. The current findings underscore the role of energy metabolism in the antidepressive activity of XYS, providing a fresh perspective on depression, and novel research strategies for revealing the mechanism of actions of traditional Chinese medicines on multi-site and multi-symptom diseases. Please cite this article as: Xiao MT, Wang SY, Wu XL, Zhao ZY, Wang HM, Liu HM, Qin XM, Liu XJ. Antidepressant mechanism of Xiaoyaosan: A perspective from energy metabolism of the brain and intestine. J Integr Med. 2025; 23(6):706-720.
Animals ; Energy Metabolism/drug effects* ; Antidepressive Agents/therapeutic use* ; Drugs, Chinese Herbal/therapeutic use* ; Brain/drug effects* ; Male ; Depression/metabolism* ; Rats ; Rats, Sprague-Dawley ; Intestines/drug effects* ; Hippocampus/drug effects*

Astragali Radix (AR) and Notoginseng Radix et Rhizoma (NR) are frequently employed in cardiovascular disease treatment. However, the efficacy of the AR-NR medicine pair (AN) in improving cardiac remodeling and its underlying mechanism remains unclear. This study aimed to evaluate AN's cardioprotective effect and potential mechanism on cardiac remodeling using transverse aortic constriction (TAC) in mice and angiotensin II (Ang II)-induced neonatal rat cardiomyocytes (NRCMs) and fibroblasts in vitro. High-performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry (HPLC-Q-TOF-MS/MS) characterized 23 main components of AN. AN significantly improved cardiac function in the TAC-induced mice. Furthermore, AN considerably reduced the serum levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), cardiac troponin T (CTn-T), and interleukin-6 (IL-6) and mitigated inflammatory cell infiltration. Post-AN treatment, TAC-induced heart size approached normal. AN decreased cardiomyocyte cross-sectional area and attenuated the upregulation of cardiac hypertrophy marker genes (ANP, BNP, and MYH7) in vivo and in vitro. Concurrently, AN alleviated collagen deposition in TAC-induced mice. AN also reduced the expression of fibrosis-related indicators (COL1A1 and COL3A1) and inhibited the activation of the transforming growth factor-β1 (TGF-β1)/mothers against decapentaplegic homolog 3 (Smad3) pathway. Thus, AN improved TAC-induced cardiac remodeling. Moreover, AN downregulated p-dynamin-related protein (Drp1) (Ser616) expression and upregulated mitogen 2 (MFN-2) and optic atrophy 1 (OPA1) expression in vivo and in vitro, thereby restoring mitochondrial fusion and fission balance. In conclusion, AN improves cardiac remodeling by regulating mitochondrial dynamic balance, providing experimental data for the rational application of Chinese medicine prescriptions with AN as the main component in clinical practice.
Animals ; Drugs, Chinese Herbal/pharmacology* ; Myocytes, Cardiac/metabolism* ; Mice ; Rats ; Male ; Mitochondrial Dynamics/drug effects* ; Ventricular Remodeling/drug effects* ; Astragalus Plant/chemistry* ; Mice, Inbred C57BL ; Rhizome/chemistry* ; Panax notoginseng/chemistry* ; Rats, Sprague-Dawley ; Natriuretic Peptide, Brain/genetics* ; Humans ; Angiotensin II ; Astragalus propinquus

Aralia taibaiensi, widely distributed in western China, particularly in the Qinba Mountains, has been utilized as a folk medicine for treating diabetes, gastropathy, rheumatism, and cardiovascular diseases. Saponins from A. taibaiensis (sAT) have demonstrated protective effects against oxidative stress and mitochondrial dysfunction induced by ischemia/reperfusion (I/R). However, the underlying mechanisms remain unclear. In vivo, middle cerebral artery occlusion/reperfusion (MCAO/R) induced inflammatory infiltration, neuronal injury, cell apoptosis, mitochondrial dysfunction, and oxidative stress in the ischaemic penumbra, which were effectively mitigated by sAT. sAT increased the mRNA and protein expression levels of apelin and its receptor apelin/apelin receptors (ARs) both in vivo and in vitro. (Ala13)-Apelin-13 (F13A) and small interfering RNA (siRNA) abolished the regulatory effects of sAT on neuroprotection mediated by adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/protein kinase B (Akt). Furthermore, sAT induced apelin/AR expression by simultaneously inhibiting P38 mitogen-activated protein kinase (P38 MAPK)/activating transcription factor 4 (ATF4) and upregulating hypoxia-inducible factor-1α (HIF-1α). Our findings indicate that sAT regulates apelin/AR/AMPK by inhibiting P38 MAPK/ATF4 and upregulating HIF-1a, thereby suppressing oxidative stress and mitochondrial dysfunction.
Animals ; Reperfusion Injury/prevention & control* ; Aralia/chemistry* ; Saponins/administration & dosage* ; AMP-Activated Protein Kinases/genetics* ; Male ; Apelin/genetics* ; Signal Transduction/drug effects* ; Neuroprotective Agents/administration & dosage* ; Brain Ischemia/genetics* ; Rats, Sprague-Dawley ; Rats ; Oxidative Stress/drug effects* ; Apelin Receptors/genetics* ; Humans ; Apoptosis/drug effects* ; Mice

Glioma, the most prevalent primary tumor of the central nervous system (CNS), is also the most lethal primary malignant tumor. Currently, there are limited chemotherapeutics available for glioma treatment, necessitating further research to identify and develop new chemotherapeutic agents. A significant approach to discovering anti-glioma drugs involves isolating antitumor active ingredients from natural products (NPs) and optimizing their structures. Additionally, targeted drug delivery systems (TDDSs) are employed to enhance drug solubility and stability and overcome the blood-brain barrier (BBB). TDDSs can penetrate deep into the brain, increase drug concentration and retention time in the CNS, and improve the targeting efficiency of NPs, thereby reducing adverse effects and enhancing anti-glioma efficacy. This paper reviews the research progress of anti-glioma activities of NPs, including alkaloids, polyphenols, flavonoids, terpenoids, saponins, quinones, and their synthetic derivatives over the past decade. The review also summarizes anti-glioma mechanisms, such as suppression of related protein expression, regulation of reactive oxygen species (ROS) levels, control of apoptosis signaling pathways, reduction of matrix metalloproteinases (MMPs) expression, blocking of vascular endothelial growth factor (VEGF), and reversal of immunosuppression. Furthermore, the functions and advantages of NP-based TDDSs in anti-glioma therapy are examined. The key information presented in this review will be valuable for the research and development of NP-based anti-glioma drugs and related TDDSs.
Humans ; Glioma/metabolism* ; Biological Products/therapeutic use* ; Animals ; Brain Neoplasms/genetics* ; Drug Delivery Systems ; Antineoplastic Agents/therapeutic use* ; Blood-Brain Barrier/metabolism* ; Apoptosis/drug effects*

Objective To explore the effects of Shuanglu Tongnao Formula on neuroinflammation in ischemic stroke (IS) rats via the P2X purinoceptor 7 receptor (P2X7R)/NLR family pyrin domain-containing 3 (NLRP3) pathway. Methods The rats were divided into five groups: the IS group, control group, Shuanglu Tongnao Formula group, P2X7R inhibitor brilliant blue G (BBG) group, and Shuanglu Tongnao Formula combined with P2X7R activator adenosine triphosphate (ATP) group, with 18 rats in each group. Except for the control group, rats in all other groups were used to construct an IS model using the suture method. After successful modeling, the drug was given once a day for 2 weeks. Neurological function scores and cerebral infarction volume ratios were measured in rats. Pathological examination of the ischemic penumbra brain tissue was performed. Immunofluorescence staining was used to quantify the proportions of microglia co-expressing both inducible nitric oxide synthase (iNOS) and ionized calcium-binding adapter molecule 1 (Iba1), as well as arginase 1 (Arg1) and Iba1, in the ischemic penumbra brain tissue. ELISA was used to detect tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta (TGF-β), interleukin 6 (IL-6) and IL-10 in the ischemic penumbra brain tissue. Western blotting was used to measure P2X7R, NLRP3, and IL-1β proteins in the ischemic penumbra brain tissue. Results Compared with the control group, the IS group showed disordered neuronal arrangement, nuclear condensation, and obvious infiltration of inflammatory cells in the ischemic penumbra; significantly elevated neurological function scores, cerebral infarction volume ratios, proportions of microglia co-expressing iNOS and Iba1, and levels of TNF-α, IL-6, and P2X7R, NLRP3, IL-1β proteins; along with reduced proportions of microglia co-expressing Arg1 and Iba1 and levels of TGF-β and IL-10. Compared with the IS group, the Zhuang medicine Shuanglu Tongnao Formula and BBG groups demonstrated alleviated brain tissue damage; reduced neurological function scores, cerebral infarction volume ratios, proportions of microglia co-expressing iNOS and Iba1, and levels of TNF-α, IL-6, and P2X7R, NLRP3, IL-1β proteins; along with increased proportions of microglia co-expressing Arg1 and Iba1 and levels of TGF-β and IL-10. ATP reversed the effects of Zhuang medicine Shuanglu Tongnao Formula on microglial polarization and neuroinflammation in IS rats. Conclusion Zhuang medicine Shuanglu Tongnao Formula may promote the transformation of microglia from M1 type to M2 type by inhibiting the P2X7R/NLRP3 pathway, thereby improving neuroinflammation in IS rats.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Receptors, Purinergic P2X7/metabolism* ; Male ; Drugs, Chinese Herbal/pharmacology* ; Rats ; Ischemic Stroke/pathology* ; Rats, Sprague-Dawley ; Disease Models, Animal ; Signal Transduction/drug effects* ; Neuroinflammatory Diseases/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Nitric Oxide Synthase Type II/metabolism* ; Interleukin-10/metabolism* ; Brain Ischemia/drug therapy* ; Microglia/metabolism*

BACKGROUND: Methylmercury (MeHg) causes damage specifically in cerebrocortical neurons, but not in hippocampal neurons. In our previous studies using cultured neurons, we found that brain-derived neurotrophic factor (BDNF), which is prominently present in hippocampal neurons, plays a key role in resistance to MeHg neurotoxicity. Our findings, combined with recent findings that moderate exercise increases BDNF in the brain, led us to hypothesize that moderate exercise protects against MeHg-induced neurotoxicity by inducing BDNF expression. METHODS: C57 black 6NJcl (C57BL/6NJcl) male mice were used to evaluate the effects of treadmill exercise (a moderate exercise) on the neurotoxicity of MeHg exposure at 1.5 mg/kg/day. The effects of treadmill exercise on MeHg neurotoxicity were evaluated through neurobehavioral, neuropathological, and biochemical analyses using brain tissue, blood, and muscle tissue. RESULTS: Treadmill exercise had a significant inhibitory effect on the neurological symptoms associated with apoptotic neuronal death and subsequent cerebrocortical neuron loss induced by MeHg exposure. In the cerebral cortex, treadmill exercise significantly increased BDNF levels and activated the neuroprotective-related BDNF-tropomyosin receptor kinase (Trk) B and p44/42 mitogen-activated protein kinase (MAPK) pathways along with significantly suppressing the neuronal cell death-associated p38 MAPK pathway. Furthermore, treadmill exercise significantly increased fibronectin type III domain containing 5 (FNDC5) expression in the muscle tissue and elevated ed the concentration of its metabolite, irisin, in the blood. CONCLUSIONS These results suggest that treadmill exercise increases BDNF in the brain and suppresses neurotoxic pathways, ultimately protecting against MeHg neurotoxicity. Moreover, the increase of BDNF in the brain may be attributed to the exercise-induced increased expression of FNDC5 in muscle tissue from where it is released into the blood as irisin and finally transferred into the brain and promoted BDNF production.
Animals ; Brain-Derived Neurotrophic Factor/genetics* ; Methylmercury Compounds/toxicity* ; Male ; Mice ; Mice, Inbred C57BL ; Physical Conditioning, Animal ; Brain/drug effects* ; Neurotoxicity Syndromes/prevention & control*

OBJECTIVES: To determine the pharmacological impact of hesperidin, the main component of Citri Reticulatae Pericarpium, on depressive behavior and elucidate the mechanism by which hesperidin treats depression, focusing on the gut-brain axis. METHODS: Fifty-four Sprague Dawley male rats were randomly allocated to 6 groups using a random number table, including control, model, hesperidin, probiotics, fluoxetine, and Citri Reticulatae Pericarpium groups. Except for the control group, rats in the remaining 5 groups were challenged with chronic unpredictable mild stress (CUMS) for 21 days and housed in single cages. The sucrose preference test (SPT), immobility time in the forced swim test (FST), and number in the open field test (OFT) were performed to measure the behavioral changes in the rats. Enzyme-linked immunosorbent assay was used to determine the levels of 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) in brain tissue, and the histopathology was performed to evaluate the changes of colon tissue, together with sequencing of the V3-V4 regions of 16S rRNA gene on feces to explore the changes of intestinal flora in the rats. RESULTS: Compared to the control group, the rats in the model group showed notable reductions in body weight, SPF, and number in OFT (P<0.01). Hesperidin was found to ameliorate depression induced by CUMS, as seen by improvements in body weight, SPT, immobility time in FST, and number in OFT (P<0.05 or P<0.01). Regarding neurotransmitters, it was found that at a dose of 50 mg/kg hesperidin treatment upregulated the levels of 5-HT and BDNF in depressed rats (P<0.05). Compared to the control group, the colon tissue of the model group exhibited greater inflammatory cell infiltration, with markedly reduced numbers of goblet cells and crypts and were significantly improved following treatment with hesperidin. Simultaneously, the administration of hesperidin demonstrated a positive impact on the gut microbiome of rats treated with CUMS, such as Shannon index increased and Simpson index decreased (P<0.01), while the abundance of Pseudomonadota and Bacteroidota increased in the hesperidin-treated group (P<0.05). CONCLUSION The mechanism responsible for the beneficial effects of hesperidin on depressive behavior in rats may be related to inhibition of the expressions of BDNF and 5-HT and preservation of the gut microbiota.
Animals ; Hesperidin/therapeutic use* ; Rats, Sprague-Dawley ; Depression/drug therapy* ; Male ; Stress, Psychological/drug therapy* ; Brain/metabolism* ; Brain-Derived Neurotrophic Factor/metabolism* ; Serotonin/metabolism* ; Gastrointestinal Microbiome/drug effects* ; Behavior, Animal/drug effects* ; Rats ; Brain-Gut Axis/drug effects* ; Chronic Disease ; Colon/drug effects*

OBJECTIVE: To investigate whether Buyang Huanwu Decoction (BYHWD) had a good curative effect on the neuroprotection of red nucleus neurons after spinal cord injury (SCI) and the possible molecular mechanism. METHODS: Ninety male Sprague-Dawley rats were divided into 5 groups (n=18 per group) according to a random number table, including the control, model, low- (12.78 g/kg, BL group), medium- (25.65 g/kg, BM group), and high-dose BYHWD groups (51.30 g/kg, BH group). A rubrospinal tract transection model in rats was established, and different doses of BYHWD were intragastrically administrated for 4 weeks. The forelimb locomotor function was recorded using the spontaneous vertical exploration test. Cyclic adenosine monophosphate (cAMP) level in red nucleus was detected through an enzyme-linked immunosorbent assay. The morphology and number of red nucleus neurons were observed using Nissl's staining and axonal retrograde tracing by Fluoro-Gold (FG). The expression of cAMP-dependent protein kinase A (PKA), nuclear factor kappa-B (NF-κB) p65, and brain-derived neurotrophic factor (BDNF) in red nucleus were detected using immunohistochemistry and quantitative real-time polymerase chain reaction. RESULTS: Compared with the control group, the utilization rate of bilateral forelimbs, unilateral right forelimbs, proportion of FG-labeled positive neurons, cAMP level, protein expressions of PKA and BDNF, and BDNF mRNA expression were significantly decreased in the model group (P<0.01), while NF-κB p65 was increased in the model group (P<0.01). Compared with the model group, the utilization rate of bilateral forelimbs and unilateral right forelimbs were significantly higher in the BL, BM and BH groups (P<0.01), the proportion of FG-labeled positive neurons, cAMP level, protein expressions of PKA and BDNF and BDNF mRNA expression in all BYHWD groups were increased (P<0.05 or P<0.01), while NF-κB p65 were decreased in all BYHWD groups (P<0.05 or P<0.01). CONCLUSIONS BYHWD possesses a sound neuroprotective effect on red nucleus neurons after SCI, and the efficacy was dose-related. The mechanism may be related to regulating the cAMP/PKA/NF-κ B p65 signaling pathway, finally promoting expression of BDNF.
Animals ; Spinal Cord Injuries/pathology* ; Drugs, Chinese Herbal/therapeutic use* ; Rats, Sprague-Dawley ; Male ; Cyclic AMP/metabolism* ; Transcription Factor RelA/metabolism* ; Cyclic AMP-Dependent Protein Kinases/metabolism* ; Signal Transduction/drug effects* ; Brain-Derived Neurotrophic Factor/genetics* ; Red Nucleus/metabolism* ; Recovery of Function/drug effects* ; Neurons/metabolism* ; Rats

OBJECTIVE: To explore the mechanism of Dihuang Yinzi (DHYZ) in the treatment of Alzheimer's disease (AD) by integrating metabolomics and experimental verification. METHODS: Forty-eight male APP/PS1 mice were divided into model, high- (DHYZ-H), medium- (DHYZ-M), and low-dose DHYZ (DHYZ-L) groups (12 mice per group) according to a random number table. Mice in DHYZ groups were gavaged with DHYZ 6.34, 12.68, and 25.35 g/(kg·d), respectively. Twelve C57BL/6 mice were gavaged with distilled water as the blank group. Metabolomics was used to analyze differential metabolites in the brains of mice. Morris water maze test was used to detect the memory abilities of mice. The hematoxylin-eosin staining and transmission electron microscopy were used to observe the general morphology and ultrastructure of neurons. The enzyme-linked immunosorbent assay was used to detect the levels of superoxide dismutase (SOD), reactive oxygen species (ROS), and amyloid β -protein 1-42 (A β_1-42). The real-time quantitative polymerase chain reaction was used to detect the mRNA expressions of density-regulated protein 1 (DRP1), fission 1 (FIS1), mitofusin-1 (MFN1), and optic atrophy protein 1 (OPA1). Western blot was used to detect the protein expressions of cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), cAMP response binding protein (CREB), brain-derived neurotrophic factor (BDNF), synapsin 1 (SYN1), synaptophysin (SYP), and postsynaptic density protein 95 (PSD95). RESULTS: A total of 82 differential metabolites were identified in the brains of APP/PS1 mice, among which 7 differential metabolites could be regulated by DHYZ. After DHYZ intervention, the memory abilities of mice significantly increased (P<0.05 or P<0.01), the number of synapses and neurons in the hippocampus increased, and the mitochondrial morphology and structure were relatively intact. The DHYZ groups exhibited a significant reduction in hippocampal ROS and A β_1-42 levels, along with a significant elevation in SOD level (P<0.05 or P<0.01). The mRNA expressions of DRP1 and FIS1 were reduced, while the mRNA expressions of MFN1 and OPA1 were increased after DHYZ treatment (P<0.05 or P<0.01). The cAMP/PKA/CREB-BDNF pathway was activated, and the expressions of SYN1, SYP and PSD95 proteins were significantly increased in the DHYZ-H group (P<0.05 or P<0.01). CONCLUSIONS DHYZ could improve mitochondrial dynamics and synaptic plasticity in APP/PS1 mice, inhibit oxidative stress, and thereby enhancing learning and memory abilities in APP/PS1 mice. Its mechanism might be related to activation of the cAMP/PKA/CREB-BDNF signaling pathway.
Animals ; Brain-Derived Neurotrophic Factor/metabolism* ; Male ; Cyclic AMP Response Element-Binding Protein/metabolism* ; Brain/drug effects* ; Metabolomics ; Mice, Inbred C57BL ; Neuronal Plasticity/drug effects* ; Drugs, Chinese Herbal/therapeutic use* ; Cyclic AMP-Dependent Protein Kinases/metabolism* ; Cyclic AMP/metabolism* ; Reactive Oxygen Species/metabolism* ; Amyloid beta-Protein Precursor/metabolism* ; Mice, Transgenic ; Mice ; Amyloid beta-Peptides/metabolism* ; Signal Transduction/drug effects* ; Alzheimer Disease/drug therapy* ; Superoxide Dismutase/metabolism*

OBJECTIVES: The neurotoxicity of carbon monoxide (CO) to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Our previous study found that retinoic acid (RA) can suppress the neurotoxic effects of CO. This study further explores, in vivo and in vitro, the molecular mechanisms by which RA alleviates CO-induced central nervous system damage. METHODS: A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO, and a DEACMP animal model was established in adult Kunming mice. Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin V/propidium iodide (PI) double staining. The transcriptional and protein expression of each gene was detected using real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Long noncoding RNA (lncRNA) SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes. In DEACMP mice, SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression. RESULTS: RA at 10 and 20 μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes, downregulation of SNHG15 and LINGO-1, and upregulation of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) (all P<0.05). Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity (all P<0.05). Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels (all P<0.05). Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP (all P<0.05). CONCLUSIONS RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes, thereby reducing central nervous system injury and exerting neuroprotective effects. LncRNA SNHG15 and LINGO-1 are key molecules mediating RA-induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway. These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
Animals ; RNA, Long Noncoding/physiology* ; Brain-Derived Neurotrophic Factor/genetics* ; Carbon Monoxide Poisoning/complications* ; Mice ; Tretinoin/pharmacology* ; Nerve Tissue Proteins/metabolism* ; Membrane Proteins/metabolism* ; Apoptosis/drug effects* ; Hippocampus/cytology* ; Receptor, trkB/metabolism* ; Neurons/drug effects* ; Male ; Brain Diseases/etiology* ; Oligodendroglia/drug effects* ; Signal Transduction ; Cell Line