Region Of Rats Research Articles

Pharmacological investigation of brucine anti-ulcer potential.

Gastric ulcer is one of the most common chronic gastrointestinal diseases characterized by a significant defect in the mucosal barrier. The current study has been conducted to evaluate the brucine anti-ulcer effect. Brucine has binding energy values ranging from −2.99 to −8.11 kcal/mol against chosen targets, according to in silico research. Brucine exhibits an inhibitory effect against Helicobacter pylori. In vivo findings revealed that brucine (3 mg/kg) showed effective results in healing ethanol-induced ulcer lesions of the gastric region in rats. Brucine showed an inhibitory effect against H+/K+-ATPase. Levels of glutathione, glutathione-s-transferase, and catalase were enhanced in the gastric rat tissue with the use of brucine, while a significant decrease in lipid peroxide levels was seen. Histopathological evaluation showed improvement in cellular architecture and a decrease in inflammatory indicators like cyclooxygenase, tumor necrosis factor, and nuclear factor kappa B expression, validated through immunohistochemistry, enzyme-linked immunosorbent assay, and Western blot techniques. In the reverse transcription–polymerase chain reaction, brucine decreased H+/K+-ATPase mRNA levels. This study reveals that brucine possesses stable binding affinities against selected targets. Brucine exhibits an anti-ulcer effect, mediated via anti-H. pylori, H+/K+-ATPase inhibition, and antioxidant and anti-inflammatory pathways.

Neuroprotective Effect of Nano Emulsion Containing Salvia on CA1 Region of Hippocampus Following Transient Global Ischemia/Reperfusion in Rat

Background: Ischemia/reperfusion (I/R) injury is one of the major causes of mortality. I/R injury leads to apoptosis in the brain, especially in the hippocampus and induces cognitive impairments. On the other hand, Salvia officinalis L. is perennial, evergreen subshrub that is widely used in traditional medicine. The antiapoptosis and antioxidant effects of Salvia officinalis L. have also been reported. Objective: In this study, we aimed to investigate the effect of Salvia officinalis L. on the expression of genes involved in apoptosis and percentage of viable neurons in the CA1 hippocampal region of rats following transient global I/R. Methods: The expression of Bcl-2, Bax, and Caspase 3 was evaluated using Real time PCR. Nissl staining was used to measure the number of viable neurons. The percentage of cell viability was also evaluated using MTT assay and flow cytometry. Salvia officinalis L. was injected intraperitoneal at the doses of 50, 75, and 100 mg/kg at both aqueous-alcoholic and aqueous extracts. Results: The expression of Bax and Caspase 3 was increased and the expression of Bcl-2 was decreased following transient global I/R in the CA1 region. The injection of Salvia officinalis L. at most doses reversed the effect of transient global I/R on genes expression. The number of viable neurons in the CA1 region was also decreased following transient global I/R and injection of Salvia officinalis L. at all doses reversed this effect. Conclusion: Transient global I/R significantly promotes apoptosis and cell death, and Salvia officinalis L. may induce neuroprotective and anti-apoptosis effects.

The anticonvulsant effect of chronic treatment with topiramate after pilocarpine-induced status epilepticus is accompanied by a suppression of comorbid behavioral impairments and robust neuroprotection in limbic regions in rats

Epilepsy is a widespread neurological disorder frequently associated with a lot of comorbidities. The present study aimed to evaluate the effects of the antiseizure medication topiramate (TPM) on spontaneous motor seizures, the pathogenesis of comorbid mood and cognitive impairments, hippocampal neuronal loss, and oxidative stress and inflammation in a rat model of temporal lobe epilepsy (TLE). Vehicle/TPM treatment (80 mg/kg, p.o.) was administered 3 h after the pilocarpine (pilo)-induced status epilepticus (SE) and continued for up to 12 weeks in Wistar rats. The chronic TPM treatment caused side effects in naïve rats, including memory disturbance, anxiety, and depressive-like responses. However, the anticonvulsant effect of this drug, administered during epileptogenesis, was accompanied by beneficial activity against comorbid behavioral impairments. The drug treatment suppressed the SE-induced neuronal damage in limbic structures, including the dorsal (CA1 and CA2 subfield), the ventral (CA1, CA2 and CA3) hippocampus, the basolateral amygdala, and the piriform cortex, while was ineffective against the surge in the oxidative stress and inflammation. Our results suggest that neuroprotection is an essential mechanism of TPM against spontaneous generalized seizures and concomitant emotional and cognitive impairments.

Mechanisms of hypoxia in the hippocampal CA3 region in postoperative cognitive dysfunction after cardiopulmonary bypass

BackgroundPostoperative cognitive dysfunction (POCD) is a complication with high morbidity and mortality, commonly observed in the elderly who underwent anesthesia and surgery. The incidence is much higher in cardiac surgery. However, the reason and the mechanism of POCD remains unclear, but cerebral hypoxia is a common neurological complication after cardiac surgery. This study aims to investigate what role cerebral hypoxia plays in the pathogenesis of POCD.MethodsThe POCD model was established using cardiopulmonary bypass (CPB) surgery. Cognitive function was detected using Y maze and Morris water maze. The hypoxia in central nervous system was assessed using HE staining, western blot, and immunofluorescence. Inflammatory factors in hippocampus and plasma were detected by enzyme-linked immunosorbent assay. Evans blue was used to detect destruction of the blood brain barrier (BBB).ResultsCognitive impairment markedly occurred to rats underwent 2-h CPB operation. Cerebral thrombosis and hypoxia occurred in the hippocampal CA3 region of rats after surgery. In addition, microglia in hippocampal was activated and the expression of inflammatory factors such as IL-1β, IL-6 and TNF-α was upregulated. Moreover, the permeability of BBB increased in rats after CPB.ConclusionHypoxia in hippocampal CA3 region was involved in the occurrence and the mechanism may be associated with neuroinflammation and the damage of BBB.

Identification of Infarct Border Zone Using Late Gadolinium Enhanced MRI in Rats

BackgroundFollowing acute myocardial infarction (MI), cardiac myocyte death and the formation of a fibrotic scar in the left ventricular free wall (LVFW) alters the biomechanical behavior of the myocardium resulting in changes to organ‐level function. Despite significant advances in understanding LVFW remodeling in the setting of MI, the extent of tissue remodeling in the regions where infarct tissue transitions to healthy tissue, commonly called the border zone (BZ), is not well understood. Additionally, the effect of alterations in biomechanical behavior of the BZ on LV pump function remains understudied. We hypothesize that image‐based cardiac modeling can effectively address this gap. To this end, our objective was to develop an automated method to identify the infarct and BZ regions in rats using ex‐vivo late gadolinium‐enhanced magnetic resonance images (LGE‐MRI) and make use of these delineations to study regional structural remodeling in MI.MethodsAnterobasal MI was induced in Wistar‐Kyoto rats (n=2) by ligating the left anterior descending artery. Prior to sacrifice, subjects in the infarct group were given gadolinium contrast agent for MRI enhancement. Animals were sacrificed at 4 weeks post‐infarct and cardiac MRI scans were performed at an isotropic 100 µm resolution. The mean value of the voxel signal‐intensity (SI) of the posterobasal region of the heart was calculated and is hereafter referred to as the baseline SI (BSI). The image voxels were then segmented in to three regions by using the following SIs as threshold value cutoffs: i) SI of greater than 125% of BSI was considered infarcted myocardium, ii) SI between 115% and 125% of BSI was considered BZ, iii) SI of less than 115% BSI was considered remote myocardium. The geometry and dimensions of the infarct region were confirmed with measurements from the excised heart of the animal.ResultsIncreased SI was noted in the anterobasal region of the infarcted hearts (Fig 1), indicating myocyte necrosis and scar formation. Mean SI of the infarct region defined via this method was 1.6‐fold larger compared to that of the remote region. The infarct region resulting from the automated identification method closely matched the gemometry and dimensions of the infarct scar region of the excised hearts.ConclusionsThe extent of myocardial remodeling in LVFW during the post‐infarct healing process determines the contractile behavior in the LVFW and influences long‐term outcomes. Automated identification of infarct, BZ, and remote myocardium regions using LGE‐MRI is a step towards image‐based characterization of the heterogenous remodeling in the LVFW. Additionally, our algorithm enables the simple definition of a BZ of varied size and could allow us to better understand the influence of distinct regional remodeling events on organ‐level function as MI proceeds from early‐stage scarring to late‐stage remodeling.

Remote contextual fear retrieval engages activity from salience network regions in rats

The ability to retrieve contextual fear memories depends on the coordinated activation of a brain-wide circuitry. Transition from recent to remote memories seems to involve the reorganization of this circuitry, a process called systems consolidation that has been associated with time-dependent fear generalization. However, it is unknown whether emotional memories acquired under different stress levels can undergo different systems consolidation processes. Here, we explored the activation pattern and functional connectivity of key brain regions associated with contextual fear conditioning (CFC) retrieval after recent (2 days) or remote (28 days) memory tests performed in rats submitted to strong (1.0 mA footshock) or mild (0.3 mA footshock) training. We used brain tissue from Wistar rats from a previous study, where we observed that increasing training intensity promotes fear memory generalization over time, possibly due to an increase in corticosterone (CORT) levels during memory consolidation. Analysis of Fos expression across 8 regions of interest (ROIs) allowed us to identify coactivation between them at both timepoints following memory recall. Our results showed that strong CFC elicits higher Fos activation in the anterior insular and prelimbic cortices during remote retrieval, which was positively correlated with freezing along with the basolateral amygdala. Rats trained either with mild or strong CFC showed broad functional connectivity at the recent timepoint whereas only animals submitted to the strong CFC showed a widespread loss of coactivation during remote retrieval. Post-training plasma CORT levels are positively correlated with FOS expression during recent retrieval in strong CFC, but negatively correlated with FOS expression during remote retrieval in mild CFC. Our findings suggest that increasing training intensity results in differential processes of systems consolidation, possibly associated with increased post-training CORT release, and that strong CFC engages activity from the aIC, BLA and PrL – areas associated with the Salience Network in rats – during remote retrieval.

Revealing directed effective connectivity of cortical neuronal networks from measurements.

In the study of biological networks, one of the major challenges is to understand the relationships between network structure and dynamics. In this paper, we model in vitro cortical neuronal cultures as stochastic dynamical systems and apply a method that reconstructs directed networks from dynamics [Ching and Tam, Phys. Rev. E 95, 010301(R) (2017)2470-004510.1103/PhysRevE.95.010301] to reveal directed effective connectivity, namely, the directed links and synaptic weights, of the neuronal cultures from voltage measurements recorded by a multielectrode array. The effective connectivity so obtained reproduces several features of cortical regions in rats and monkeys and has similar network properties as the synaptic network of the nematode Caenorhabditis elegans, whose entire nervous system has been mapped out. The distribution of the incoming degree is bimodal and the distributions of the average incoming and outgoing synaptic strength are non-Gaussian with long tails. The effective connectivity captures different information from the commonly studied functional connectivity, estimated using statistical correlation between spiking activities. The average synaptic strengths of excitatory incoming and outgoing links are found to increase with the spiking activity in the estimated effective connectivity but not in the functional connectivity estimated using the same sets of voltage measurements. These results thus demonstrate that the reconstructed effective connectivity can capture the general properties of synaptic connections and better reveal relationships between network structure and dynamics.

Chronic Intermittent Sucrose Consumption Facilitates the Ability to Discriminate Opioid Receptor Blockade with Naltrexone in Rats.

The opioid antagonist naltrexone (NTX) decreases intake of preferred diets in rats at very low doses relative to doses needed to decrease intake of “bland” laboratory chow. In the absence of an opioid agonist, NTX is not discriminable using operant techniques. In the current study, we found that rats given intermittent access to a 25% sucrose solution learned to discriminate between various naltrexone doses and saline. None of the rats given only water learned to discriminate between naltrexone and saline. When access to the sucrose solution was discontinued for 14 days, the rats lost the ability to discriminate between NTX and saline. We also studied the changes of c-Fos IR in selected brain regions in rats treated with saline versus NTX that were drinking water or 25% sucrose. An injection of NTX or saline resulted in a significant drug, diet, and interaction effect in various brain regions associated with feeding behavior, particularly the amygdala, accumbens, and hypothalamic sites. Thus, we found that ingestion of a sucrose solution results in the ability of rats to reliably discriminate naltrexone administration. In addition, sucrose and naltrexone altered c-Fos IR in an interactive fashion in brain regions known to be involved in ingestion behavior.

RETRACTION NOTE: Effect of curcumin on hippocampus dentate gyrus injury induced by nicotine in rats

This paper was published in the Journal of Herbmed Pharmacology in 2019 (doi: 10.15171/jhp.2019.47) (1). Based on an email received from the team of young researchers recently, we were informed that the results of this article (some figures and diagrams) have been published in several similar articles (2-5), which are considered ethical misconduct. This issue was investigated by the editorial team of the Journal of Herbmed Pharmacology. As a result, based on the Committee on Publication Ethics (COPE) guidelines, the editors decided to retract this paper. The authors were informed and advised on this serious ethical breach. This article has been retracted at the request of the corresponding author. The retracted article will remain online to maintain the scholarly record, but it will be watermarked on each page as ‘retracted’.

Hypothermia selectively protects the anterior forebrain mesocircuit during global cerebral ischemia.

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°C. 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°C, the rat models of global cerebral ischemia established at 31-33°C 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.

Low-Dose PET Imaging of Tumors in Lung and Liver Regions Using Internal Motion Estimation

Motion estimation and compensation are necessary for improvement of tumor quantification analysis in positron emission tomography (PET) images. The aim of this study was to propose adaptive PET imaging with internal motion estimation and correction using regional artificial evaluation of tumors injected with low-dose and high-dose radiopharmaceuticals. In order to assess internal motion, molecular sieves imitating tumors were loaded with 18F and inserted into the lung and liver regions in rats. All models were classified into two groups, based on the injected radiopharmaceutical activity, to compare the effect of tumor intensity. The PET study was performed with injection of F-18 fluorodeoxyglucose (18F-FDG). Respiratory gating was carried out by external trigger device. Count, signal to noise ratio (SNR), contrast and full width at half maximum (FWHM) were measured in artificial tumors in gated images. Motion correction was executed by affine transformation with estimated internal motion data. Monitoring data were different from estimated motion. Contrast in the low-activity group was 3.57, 4.08 and 6.19, while in the high-activity group it was 10.01, 8.36 and 6.97 for static, 4 bin and 8 bin images, respectively. The results of the lung target in 4 bin and the liver target in 8 bin showed improvement in FWHM and contrast with sufficient SNR. After motion correction, FWHM was improved in both regions (lung: 24.56%, liver: 10.77%). Moreover, with the low dose of radiopharmaceuticals the PET image visualized specific accumulated radiopharmaceutical areas in the liver. Therefore, low activity in PET images should undergo motion correction before quantification analysis using PET data. We could improve quantitative tumor evaluation by considering organ region and tumor intensity.

Abstract 9101: RVLM Microinjection to Explain the Role of Metabotropic Glutamate Receptors in the Regulation of Baseline Blood Pressure and Heart Rate in SHRSP

Introduction: Glutamate (Glu) is activated by the stimulation of its receptors. The microinjection of Glu in rostral ventrolateral medulla (RVLM) elicited a rapid and large increase in blood pressure (BP) and heart rate (HR), which is inhibited with kynurenic acid (KYN), a selective inhibitor of ionotropic glutamate receptors (iGluR). Further, we showed that the response to Glu was much greater in stroke-prone spontaneously hypertensive rats (SHRSP) than that in Wistar Kyoto (WKY) rats, indicating that iGluR in RVLM played an important role to maintain high BP & HR in SHRSP. Whereas, the role of metabotropic glutamate receptors (mGluR) in RVLM were not fully elucidated in SHRSP yet. Hypotheses: Since the different mGluR types, e.g., group I (mGluR1, mGluR5), group II (mGluR2, mGluR3) & group III (mGluR4, mGluR6, mGluR7, mGluR8), are expressed in the various regions of rat’s brain, and several studies reported that mGluR5 is largely expressed in RVLM of rats; in this study we evaluated the pathophysiological role(s) of mGluR5, expecting that mGluR5 in RVLM keeps high baseline (i) BP and (ii) HR in SHRSP. Method: MTEP (10 nmole, a highly selective mGluR5 antagonist) and KYN (4 nmole) were microinjected unilaterally in RVLM in SHRSP (n=10) and WKY (n=10) to determine the effects on baseline BP & HR. In addition, the effects of two inhibitors on response to Glu (5 nmole) microinjection were observed. Results: MTEP reduced baseline BP & HR significantly in SHRSP when compared to those in WKY (ΔMAP: -30±3 vs. -3±2 mmHg, ΔHR: -35±3 vs. -4±2 bpm, respectively, p< 0.05), but failed to attenuate a response to Glu microinjection. In contrast, KYN had no significant effects on baseline BP & HR in the two strains, whereas it showed an inhibitory effect on the response to microinjected Glu, which was significantly greater in SHRSP than that in WKY. Conclusions: This study suggested that mGluR5 in RVLM played a major role in the maintenance of high baseline BP & HR in SHRSP.

Gene expression profiles of multiple brain regions in rats differ between developmental and postpubertal exposure to valproic acid.

We have previously reported that the valproic acid (VPA)-induced disruption pattern of hippocampal adult neurogenesis differs between developmental and 28-day postpubertal exposure. In the present study, we performed brain region-specific global gene expression profiling to compare the profiles of VPA-induced neurotoxicity between developmental and postpubertal exposure. Offspring exposed to VPA at 0, 667, and 2000 parts per million (ppm) via maternal drinking water from gestational day 6 until weaning (postnatal day 21) were examined, along with male rats orally administered VPA at 0, 200, and 900 mg/kg body weight for 28 days starting at 5weeks old. Four brain regions-the hippocampal dentate gyrus, corpus callosum, cerebral cortex, and cerebellar vermis-were subjected to expression microarray analysis. Profiled data suggested a region-specific pattern of effects after developmental VPA exposure, and a common pattern of effects among brain regions after postpubertal VPA exposure. Developmental VPA exposure typically led to the altered expression of genes related to nervous system development (Msx1, Xcl1, Foxj1, Prdm16, C3, and Kif11) in the hippocampus, and those related to nervous system development (Neurod1) and gliogenesis (Notch1 and Sox9) in the corpus callosum. Postpubertal VPA exposure led to the altered expression of genes related to neuronal differentiation and projection (Cd47, Cyr61, Dbi, Adamts1, and Btg2) in multiple brain regions. These findings suggested that neurotoxic patterns of VPA might be different between developmental and postpubertal exposure, which was consistent with our previous study. Of note, the hippocampal dentate gyrus might be a sensitive target of developmental neurotoxicants after puberty.

MicroRNA-204-5p reduction in rat hippocampus contributes to stress-induced pathology via targeting RGS12 signaling pathway

BackgroundNeuroinflammation occupies a pivotal position in the pathogenesis of most nervous system diseases, including depression. However, the underlying molecular mechanisms of neuroinflammation associated with neuronal injury in depression remain largely uncharacterized. Therefore, identifying potential molecular mechanisms and therapeutic targets would serve to better understand the progression of this condition.MethodsChronic unpredictable stress (CUS) was used to induce depression-like behaviors in rats. RNA-sequencing was used to detect the differentially expressed microRNAs. Stereotactic injection of AAV virus to overexpress or knockdown the miR-204-5p. The oxidative markers and inflammatory related proteins were verified by immunoblotting or immunofluorescence assay. The oxidative stress enzyme and products were verified using enzyme-linked assay kit. Electron microscopy analysis was used to observe the synapse and ultrastructural pathology. Finally, electrophysiological recording was used to analyze the synaptic transmission.ResultsHere, we found that the expression of miR-204-5p within the hippocampal dentate gyrus (DG) region of rats was significantly down-regulated after chronic unpredicted stress (CUS), accompanied with the oxidative stress-induced neuronal damage within DG region of these rats. In contrast, overexpression of miR-204-5p within the DG region of CUS rats alleviated oxidative stress and neuroinflammation by directly targeting the regulator of G protein signaling 12 (RGS12), effects which were accompanied with amelioration of depressive-like behaviors in these CUS rats. In addition, down-regulation of miR-204-5p induced neuronal deterioration in DG regions and depressive-like behaviors in rats.ConclusionTaken together, these results suggest that miR-204-5p plays a key role in regulating oxidative stress damage in CUS-induced pathological processes of depression. Such findings provide evidence of the involvement of miR-204-5p in mechanisms underlying oxidative stress associated with depressive phenotype.Graphical

Ventoluft Polyherbal formulation modulates Freund’s Complete Adjuvant induced arthritis in experimental rats

Background: Ventoluft Polyherbal formulation composes multiple traditional medicinal plants composed of various anti-inflammatory agents. Hence, the present study aimed to investigate the effect of Ventoluft Polyherbal formulation on Freund’s complete adjuvant-induced arthritic male Wistar rats. Materials and methods: The study included thirty-six rats, containing six in each. Arthritis was induced by injecting FCA (0.1ml) in joints of the right sub-plantar region of rats in negative control and all test groups i.e. (20, 40, and 80mg/kg p.o) for 28 days except normal group. A positive control, indomethacin (10mg/kg, i.p.) was also tested for 28 days. During the treatment, paw volume was measured weekly once. At the end of the experiment, physical, hematological, and biochemical effects were evaluated. Results:Administration of Ventoluft at the doses of 20, 40, and 80 mg/kg b.w. p.o exhibited statistically significant (p < 0.001) inhibition of the paw edema and joint swelling, along with an increase in body weight, decrease in rheumatoid and spleen index factors. Conclusion: The results from hematological and biochemical parameters have shown that Ventoluft possesses potent anti-arthritic activity, Results obtained in the present study indicate that Ventoluft formulation has exhibited, dose-dependent improvement in FCA induced rheumatoid arthritis.

Acupuncture intervention prolongates thrombolysis time window by regulating cerebral cortex angiogenesis-related genes and proteins in cerebral infarction rats

To observe the effect of acupuncture on the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and endostatin (Endostatin, ES) mRNAs and proteins (angiogenesis related factors) in the ischemic penumbra region in rats with cerebral infarction (CI), so as to explore its underlying mechanisms in prolonging the time window of thrombolysis therapy for CI. A total of 48 male SD rats were randomly divided into sham operation, model, medication (6 h thrombolysis) and acupuncture (Acupunct)+medication groups (n=12 in each group). The CI model was established using modified auto-thrombus method. Six hours after thrombolysis, recombinant human tissue plasminogen activator (rt-PA,10 mg/kg) was given to rats of the thrombolysis group through tail vein. Acupuncture was applied at "Shuigou"(CV26) and bilateral "Neiguan" (PC6) 2 h after successful modeling, and the needles were retained for 30 minutes. Cerebral blood flow (CBF) was monitored during modeling in each group, and the neurological deficit score (0-7 points) was given 2 h and 24 h after successful modeling according to Bederson's methods. The cerebral infarction volume was observed after triphenyltetrazole chloride (TTC) staining. The protein and mRNA expression levels of VEGF, bFGF and ES in the ischemic penumbra region of the right cerebral cortex were detected by Western blot and real-time PCR, separately. The neurological deficit score at both 2 h and 24 h after modeling, percentage of cerebral infarction volume, and the expression levels of VEGF, bFGF and ES proteins and mRNAs in the model group were significantly higher than those of the sham operation group (P<0.01, P < 0.05). Compared with the model group, the neurological deficit score 24 h (not at 2 h) after modeling and percentage of cerebral infarction volume, and the expression levels of ES protein and mRNA in the Acupunct+medication group (not in the medication group) were notably lower (P<0.05, P<0.01), while the expression levels of VEGF and bFGF proteins and mRNAs in the Acupunct +medication group (not in the medication group) were considerably higher (P<0.01, P<0.05). No significant differences were found between medication and model groups in the CI percentage, VEGF, bFGF and ES proteins and mRNAs (P>0.05). The therapeutic effect of Acupunct +medication group was significantly superior to that of medication in lowering neurological deficit score, percentage of CI volume and expression of ES protein and mRNA and in up-regulating the expression of VEGF and bFGF proteins and mRNAs (P<0.05, P<0.01). Acupuncture and timely intervention can prolong the time window of thrombolysis in CI rats, which may be related to its function in up-regulating the expression of VEGF and bFGF mRNAs and proteins and in down-regulating the expression of ES mRNA and protein in ischemic cerebral cortex.

Lycopene-Loaded Microemulsion Regulates Neurogenesis in Rats with Aβ-Induced Alzheimer's Disease Rats Based on the Wnt/β-catenin Pathway.

Objective To investigate the effects of lycopene-loaded microemulsion (LME) on the cognitive function and neurogenesis in the dentate gyrus (DG) of the hippocampus and subventricular (SVZ) region of rats with amyloid β- (Aβ-) induced Alzheimer's disease (AD) and its mechanism based on the Wnt/β-catenin pathway. Methods Healthy Wistar rats were divided into four groups: the blank control (CON), AD control, traditional lycopene (LOO), and LME groups. The CON and AD groups were fed with normal saline, while the LOO group was fed with traditional lycopene, and the LME group was fed with lycopene-loaded microemulsion. Behavioral tests were performed after three weeks of gastric administration. Immunofluorescence-labeled cells were used to observe the differentiation and maturation of new nerve cells in the DG of the hippocampus and SVZ region. qRT-PCR and Western blotting detected the expression of neurogenesis genes and Wnt/β-catenin pathway-related proteins, respectively. Results On the Morris water maze test, LME rats had significantly shortened movement trajectory on the searching platform, reduced escape latency time, and increased residence time on the original platform quadrant. In addition, more LME rats crossed the platform when it was removed. Thus, LME can improve the spatial learning and memory of Aβ-induced AD rats. On qRT-PCR, LME significantly increased Reelin, Nestin, and Pax6 gene expressions, which regulate neurogenesis. Immunofluorescence showed that LME could significantly increase BrdU+, Dcx+, BrdU+/Neun+, BrdU+/Dcx+ cells in the DG and SVZ regions, thus promoting neurogenesis. LME also reduced the number of Iba1+ and Iba1+/BrdU+ cells, thus reducing the neuroinflammatory response. On Western blot, LME upregulated the Wnt/β-catenin pathway by upregulating Wnt3a, β-catenin, Disheveled (Dvl), and p-GSK3β and downregulating p-β-catenin and GSK3β. Conclusion LME attenuates cognitive impairment in Aβ-induced AD rats by promoting neurogenesis in the hippocampus and SVZ region through upregulating the Wnt/β-catenin pathway.

2-Heptanone reduces inhibitory control of the amygdala over the prelimbic region in rats

Basolateral amygdala (BLA) nuclei and their reciprocal connections with prelimbic (PL) and infralimbic (IL) regions of the medial prefrontal cortex (mPFC) are involved in the regulation of fear. 2-Heptanone is released in urine in stressed rats, and the olfactory detection of this odor produces immediate avoidance and alarm reactions and modifies neuronal activity in limbic connections in non-stressed rats. If 2-heptanone acts as a danger signal, then long-lasting actions would be expected. The aim of the present study was to investigate whether the forced inhalation of 2-heptanone modifies the response capacity of the BLA-mPFC circuit in the long term (48 h). Single-unit extracellular recordings were obtained from the PL and IL during electrical stimulation of the BLA (square-wave pulses; 1 ms, 20 µA, 0.3 Hz, 110 stimuli over a total duration of 360 s) in three groups of Wistar rats: control group (no sensory stimulation), unpredictable auditory stimulation group, and 2-heptanone stimulation group. A brief-latency (1 ms), short-duration (5 ms) paucisynaptic response followed BLA stimulation and was unaffected by any sensorial stimulation. The paucisynaptic response was followed by a mostly inhibitory and long-lasting (>750 ms) afterdischarge in the control and auditory stimulation groups. In the 2-heptanone group, the inhibitory afterdischarge shifted to an excitatory afterdischarge after ∼250 ms in the PL and after ∼500 ms in the IL. Importantly, the rats that were included in this study were born in local housing facilities. Thus, these animals were never in contact with predators and instead in contact with only conspecifics. These results indicate that the forced inhalation of 2-heptanone is able to modify BLA-mPFC responsivity in the long term. 2-Heptanone decreases inhibitory control of the amygdala over mPFC activity. Disinhibition of the mPFC may lead to the adaptive expression of defensive behaviors, even in animals that are not in the presence of predators.

Oxygen Enrichment Mitigates High-Altitude Hypoxia-Induced Hippocampal Neurodegeneration and Memory Dysfunction Associated with Attenuated Tau Phosphorylation.

Cai, Jing, Junyong Ruan, Xi Shao, Yuanjun Ding, Kangning Xie, Chi Tang, Zedong Yan, Erping Luo, and Da Jing. Oxygen enrichment mitigates high-altitude hypoxia-induced hippocampal neurodegeneration and memory dysfunction associated with attenuated tau phosphorylation. High Alt Med Biol. 22:274-284, 2021. Background: Brain is predominantly vulnerable to high-altitude hypoxia (HAH), resulting in neurodegeneration and cognitive impairment. The technology of oxygen enrichment has proven effective to decrease the heart rate and improve the arterial oxygen saturation by reducing the equivalent altitude. However, the efficacy of oxygen enrichment on HAH-induced cognitive impairments remains controversial based on the results of neuropsychological tests, and its role in HAH-induced hippocampal morphological and molecular changes remains unknown. Therefore, this study aims to systematically investigate the effects of oxygen enrichment on the memory dysfunction and hippocampal neurodegeneration caused by HAH. Materials and Methods: Fifty-one male Sprague-Dawley rats were equally assigned to three groups: normal control, HAH, and HAH with oxygen enrichment (HAHO). Rats in the HAH and HAHO groups were exposed to hypoxia for 3 days in a hypobaric hypoxia chamber at a simulated altitude of 6,000 m. Rats in the HAHO group were supplemented with oxygen-enriched air, with 12 hours/day in the hypobaric hypoxia chamber. Results: Our results showed that oxygen enrichment improved the locomotor activity of HAH-exposed rats. The Morris water maze test revealed that oxygen enrichment significantly ameliorated HAH-induced spatial memory deficits. Oxygen enrichment also improved morphological alterations of pyramidal cells and the ultrastructure of neurons in the hippocampal CA1 region in rats exposed to acute HAH. Tau hyperphosphorylation at Ser396, Ser262, Thr231, and Thr181 was also significantly attenuated by oxygen enrichment in HAH-exposed rats. Conclusions: Together, our study reveals that oxygen enrichment can ameliorate HAH-induced cognitive impairments associated with improved hippocampal morphology and molecular expression, and highlights that oxygen enrichment may become a promising alternative treatment against neurodegeneration for humans ascending to the plateau.

The impact of hypoestrogenism and occlusal function on MMP1, MMP8 and MMP13 expression in the odontogenic region in rats

Background: The impact of estrogen deficiency and occlusion in the matrix metalloproteinases (MMPs) expression in dental tissues has not yet been elucidated. Objective: To evaluate the influence of estrogen deficiency and occlusal hypofunction and hyperfunction on the gene expression of MMP1, MMP8 and MMP13 in the odontogenic region of teeth in continuous growth, in the murine model. Material and methods: Rats (Wistar Hannover lineage) were divided into two groups according to the intervention received: Hypoestrogenism Group - ovariectomy surgery and Control Group - fictitious surgery. Occlusal hypofunction and hyperfunction conditions were also established in all animals (each animal presented both conditions). After euthanasia, the hemimandibles were removed to evaluate the gene expression through real time PCR. T-test was used to compare the mean differences between groups (P&lt;0.05). Results: There was no statistically significant difference of the relative gene expression of MMP1, MMP8 and MMP13 between the hypoestrogenism and control groups (P&gt;0.05). A statistically significant difference of the relative MMP13 expression between the occlusal hypofunction and hyperfunction tooth was observed (P=0.03). In the hypoestrogenism group, MMP13 was overexpressed in hypofunction tooth (P=0.045). Conclusion: Occlusal function affects MMP13 expression in the odontogenic region, in murine model.