Cerebral arterial blood flow,attention,and executive and cognitive functions in depressed patients after acute hypertensive cerebral hemorrhage

BACKGROUND Intracerebral hemorrhage mainly occurs in middle-aged and elderly patients with hypertension,and surgery is currently the main treatment for hypertensive cerebral hemorrhage,but the bleeding caused by surgery will cause damage to the patient's nerve cells,resulting in cognitive and motor dysfunction,resulting in a decline in the patient's quality of life.AIM To investigate associations between cerebral arterial blood flow and executive and cognitive functions in depressed patients after acute hypertensive cerebral hemorrhage.METHODS Eighty-nine patients with depression after acute hypertensive cerebral hemorrhage who were admitted to our hospital between January 2019 and July 2021 were selected as the observation group,while 100 patients without depression who had acute hypertensive cerebral hemorrhage were selected as the control group.The attention span of the patients was assessed using the Paddle Pin Test while executive function was assessed using the Wisconsin Card Sorting Test(WCST)and cognitive function was assessed using the Montreal Cognitive Assessment Scale(MoCA).The Hamilton Depression Rating Scale(HAMD-24)was used to evaluate the severity of depression of involved patients.Cerebral arterial blood flow was measured in both groups.RESULTS The MoCA score,net scores I,II,III,IV,and the total net score of the scratch test in the observation group were significantly lower than those in the control group(P<0.05).Concurrently,the total number of responses,number of incorrect responses,number of persistent errors,and number of completed responses of the first classification in the WCST test were significantly higher in the observation group than those in the control group(P<0.05).Blood flow in the basilar artery,left middle cerebral artery,right middle cerebral artery,left anterior cerebral artery,and right anterior cerebral artery was significantly lower in the observation group than in the control group(P<0.05).The basilar artery,left middle cerebral artery,right middle cerebral artery,left anterior cerebral artery,and right anterior cerebral artery were positively correlated with the net and total net scores of each part of the Paddle Pin test and the MoCA score(P<0.05),and negatively correlated with each part of the WCST test(P<0.05).In the observation group,the post-treatment improvement was more prominent in the Paddle Pin test,WCST test,HAMD-24 score,and MoCA score compared with those in the pre-treatment period(P<0.05).Blood flow in the basilar artery,left middle cerebral artery,right middle cerebral artery,left anterior cerebral artery,and right anterior cerebral artery significantly improved in the observation group after treatment(P<0.05).CONCLUSION Impaired attention,and executive and cognitive functions are correlated with cerebral artery blood flow in patients with depression after acute hypertensive cerebral hemorrhage and warrant further study.

Outcomes of the effect of exercise on cognitive function in patients with depression:A meta-analysis

BACKGROUND Major depressive disorder is a common mental disorder,characterized by a high rate of suicide and recurrence,which is frequently accompanied by cognitive impairments,particularly in executive function,memory,attention,and infor-mation processing speed.As such,improving the cognitive function in patients with depression and enhancing their quality of life are urgent issues.AIM To perform a systematic review and meta-analysis of the effects of exercise on cognitive function in patients with depression.METHODS The PubMed,Web of Science,Cochrane Library,Embase,China National Knowledge Infrastructure,Wanfang Medical,VIP,and Biomedical Databases for randomized controlled trials(RCTs)databases were searched(from inception to October 19,2023)for studies investigating improvements in cognitive function in patients with depression through exercise.Tools recommended by the Cochrane Handbook for RCT evaluation,and GRADEpro and Stata17 software,were employed for risk of bias assessment,evidence grading,forest plot construction,subgroup and sensitivity analyses,and assessment of publication bias.RESULTS Seventeen RCTs(1173 patients with depression)were included.Exercise had a small but significant positive effect on attention,with an effect size of 0.21,95%CI:0.07-0.34,P<0.01.Specifically,aerobic exercise regimens of 30-60 minute/session,thrice a week,at moderate intensity,and sustained over 3-12 weeks,were associated with the most pronounced benefits(P<0.05),with effect sizes for executive function,memory,and information processing speed of 0.11,95%CI:-0.11-0.32,P=0.34;0.08,95%CI:0.00-0.16,P=0.05;and 0.14,95%CI:0.04-0.25,P=0.01,respectively.The evidence levels for attention,information processing speed,and memory were rated as'low,’whereas that for executive function was rated as'very low’.CONCLUSION Exercise could improve attention and information-processing speed in patients with depression,although improvements in executive function and memory are not significant.

Relationship between intracranial pressure and neurocognitive function among older adults after radical resection of rectal cancer

BACKGROUND Older patients are prone to postoperative cognitive decline after laparoscopic rectal cancer surgery,which may be associated with increased intraoperative intracranial pressure(ICP).This study investigated the correlation between intra-operative ICP changes,as indicated by measurements of the optic nerve sheath diameter(ONSD)using ultrasonography,and subsequent cognitive function to provide better patient care.AIM To evaluate changes in ICP and associated postoperative neurocognition in older adults after laparoscopic radical resection for rectal cancer.METHODS We included 140 patients who visited the Mianyang Central Hospital for malig-nant rectal tumors,measured their ONSDs before surgery and 30 and 60 minutes after the Trendelenburg position during surgery,and evaluated the patients’cog-nitive function 1 day before surgery and 1,4,and 7 days after surgery.The Mini-Mental State Examination(MMSE)and confusion assessment method(CAM)scores of the patients with different ONSDs were compared at different times after surgery.RESULTS In patients with an ONSD greater than 5.00 mm(group A1),the MMSE scores at 1 day and 4 days after surgery were significantly lower than those of patients with an ONSD less than or equal to 4.00 mm(group A2)(P<0.05).The CAM scores of group A1 were significantly higher than those of group A2(P<0.05).The MMSE scores of group A1 on days 1 and 4 after surgery were significantly lower than those 1 day before and 7 days after surgery(P<0.05),while the CAM scores 1 day and 4 days after surgery were significantly higher than those 1 day before and 7 days after surgery.CONCLUSION Decline in cognitive function among older adults after the procedure may be related to intracranial hypertension during surgery.

Abnormalities of electroencephalography microstates in patients with depression and their association with cognitive function

BACKGROUND A growing number of recent studies have explored underlying activity in the brain by measuring electroencephalography(EEG)in people with depression.However,the consistency of findings on EEG microstates in patients with depression is poor,and few studies have reported the relationship between EEG microstates,cognitive scales,and depression severity scales.AIM To investigate the EEG microstate characteristics of patients with depression and their association with cognitive functions.METHODS A total of 24 patients diagnosed with depression and 32 healthy controls were included in this study using the Structured Clinical Interview for Disease for The Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition.We collected information relating to demographic and clinical characteristics,as well as data from the Repeatable Battery for the Assessment of Neuropsychological Status(RBANS;Chinese version)and EEG.RESULTS Compared with the controls,the duration,occurrence,and contribution of microstate C were significantly higher[depression(DEP):Duration 84.58±24.35,occurrence 3.72±0.56,contribution 30.39±8.59;CON:Duration 72.77±10.23,occurrence 3.41±0.36,contribution 24.46±4.66;Duration F=6.02,P=0.049;Occurrence F=6.19,P=0.049;Contribution F=10.82,P=0.011]while the duration,occurrence,and contribution of microstate D were significantly lower(DEP:Duration 70.00±15.92,occurrence 3.18±0.71,contribution 22.48±8.12;CON:Duration 85.46±10.23,occurrence 3.54±0.41,contribution 28.25±5.85;Duration F=19.18,P<0.001;Occurrence F=5.79,P=0.050;Contribution F=9.41,P=0.013)in patients with depression.A positive correlation was observed between the visuospatial/constructional scores of the RBANS scale and the transition probability of microstate class C to B(r=0.405,P=0.049).CONCLUSION EEG microstate,especially C and D,is a possible biomarker in depression.Patients with depression had a more frequent transition from microstate C to B,which may relate to more negative rumination and visual processing.

Associations between residence and cognitive function among Chinese older adults: the mediating role of leisure activity

Background:Cognitive function is a current research hotspot,residence may be related to differences in cognitive function,and the mediating role of leisure activities are limited in Chinese research.This study used leisure activities as a mediating variable to investigate the mediating role of leisure activity between place of residence(city-town-rural)and cognitive function among Chinese older,this is where the innovation of the article comes in.Methods:Using cross-sectional data from the 2018 Chinese Longitudinal Healthy Longevity Survey,Pearson correlation analyses were employed to examine the relationships among various indicators.Mediation analyses were conducted using the SPSS PROCESS macro program,version 3.5,written by Hayes,to explore the mediating effects of leisure activity between place of residence and cognitive function in older adults.Results:A total of 10955 older adults were included in this study,with a mean age of(84.23±11.57)years.Among them,2739(24.8%)lived in the city,3627(33.1%)in town,and 4615(42.1%)in rural areas;their leisure activity score was(5.34±3.77),and their cognitive function score was(24.69±6.65).Place of residence,leisure activities,and cognitive function were significantly correlated(P<0.01).Using city as a reference,place of residence is negatively associated with cognitive function,and place of residence not only had a direct effect on cognitive function in older adults:town-cognitive function(effect=–0.399;95%confidence interval(CI)=(–0.685,–0.113));rural-cognitive function(effect=–0.42;95%CI=(–0.698,–0.141)).There were also indirect effects on cognitive function through the pathway of leisure activity:town-leisure activity-cognitive function(effect=–0.17;95%CI=(–0.246,–0.1)),rural-leisure activity-cognitive function(effect=–0.199;95%CI=(–0.272,–0.13)).Conclusion:Leisure activities play a partially mediating role between the impact of place of residence and cognitive function in Chinese older adults,and it is vital to pay attention to the impact of place of residence on the cognitive function of older adults in various aspects,and to increase the participation rate of older adults in leisure activities,which is beneficial to the prevention of cognitive decline and the protection of older adult’s physical and mental health.

Diabetes and cognitive function:An evidence-based current perspective

Several epidemiological studies have clearly identified diabetes mellitus(DM)as a major risk factor for cognitive dysfunction,and it is going to be a major public health issue in the coming years because of the alarming rise in diabetes prevalence across the world.Brain and neural tissues predominantly depend on glucose as energy substrate and hence,any alterations in carbohydrate metabolism can directly impact on cerebral functional output including cognition,executive capacity,and memory.DM affects neuronal function and mental capacity in several ways,some of which include hypoperfusion of the brain tissues from cerebrovascular disease,diabetes-related alterations of glucose transporters causing abnormalities in neuronal glucose uptake and metabolism,local hyper-and hypometabolism of brain areas from insulin resistance,and recurrent hypoglycemic episodes inherent to pharmacotherapy of diabetes resulting in neuronal damage.Cognitive decline can further worsen diabetes care as DM is a disease largely self-managed by patients.Therefore,it is crucial to understand the pathobiology of cognitive dysfunction in relation to DM and its management for optimal long-term care plan for patients.A thorough appraisal of normal metabolic characteristics of the brain,how alterations in neural metabolism affects cognition,the diagnostic algorithm for patients with diabetes and dementia,and the management and prognosis of patients when they have this dangerous combination of illnesses is imperative in this context.This evidence-based narrative with the backup of latest clinical trial reviews elaborates the current understanding on diabetes and cognitive function to empower physicians to manage their patients in day-to-day clinical practice.

Treatment outcomes and cognitive function following electroconvulsive therapy in patients with severe depression

BACKGROUND Traditional treatments for major depressive disorder(MDD),including medication and therapy,often fail and have undesirable side effects.Electroconvulsive therapy(ECT)uses electrical currents to induce brief seizures in the brain,resulting in rapid and potent antidepressant effects.However,owing to misconceptions and controversies,ECT is not as widely used as it could and often faces stigmatization.AIM To evaluate the efficacy and safety of ECT compared to those of medication and/or therapy in patients with severe MDD.METHODS This prospective cohort study included 220 individuals with severe MDD who were divided into the ECT and non-ECT groups.The patients in the ECT group underwent bilateral ECT three times a wk until they either achieved remission or reached a maximum of 12 sessions.The non-ECT group received medication and/or therapy according to clinical guidelines for MDD.The primary outcome was the variation in the hamilton depression rating scale(HDRS)score from treatment/ECT initiation to week 12.In addition,patients’quality of life,cognitive abilities,and biomarkers were measured throughout the study.RESULTS Although both groups showed significant improvements in their HDRS scores over time,the improvement was more pronounced in the ECT group than in the non-ECT group.Additionally,the ECT group exhibited a more substantial improvement in the quality of life and cognitive function than those of the non-ECT group.Compared with the non-ECT group,the ECT group exhibited evidently lower variations in the brain-derived neurotrophic factor(BDNF)and cytokine interleukin-6(IL-6)levels.The side effects were generally mild and comparable between the two groups.ECT is safer and more potent than medication and/or therapy in mitigating depressive symptoms,enhancing wellbeing,and bolstering cognitive capabilities in individuals with severe MDD.ECT may also affect the levels of BDNF and IL-6,which are indicators of neuroplasticity and inflammation,respectively.CONCLUSION ECT has emerged as a potentially advantageous therapeutic approach for patients with MDD who are unresponsive to alternative treatments.

Association between vision and cognitive function among community-dwelling older adults in Selangor,Malaysia

AIM:To determine the association between distance and near visual acuity(VA)and cognitive function among older adults in Selangor,Malaysia.METHODS:A total of 230 older adults(age≥60y)participated in this study.Habitual distance and near VA were measured using the Early Treatment Diabetic Retinopathy Study Chart and Lighthouse Near Visual Acuity Chart,respectively.Global cognitive function was assessed using the Mini-Mental State Examination(M-MSE)and the Malay language version of the Montreal Cognitive Assessment(M-MoCA).Digit Symbol(DS)subtest was used to measure information processing.RESULTS:No significant association was observed between vision and M-MSE and M-MoCA scores.However,poor distance and near VA were found to be significantly associated with low DS scores[distance VA:β=-0.01,R2=0.1,P=0.02;odds ratio(OR)=2.84,95%confidence interval(CI),1.10-7.33,P=0.03;near VA:β=-0.05,R2=0.08,P=0.00;OR=3.32,95%CI,1.28-8.59,P=0.01].CONCLUSION:Poor vision is associated with a decline in information processing in older adults and substantiates the importance of preserving good vision in maintaining cognitive function.

Maternal stress exposure during pregnancy impairs ultrastructural changes in the white matter and reduces cognitive function in offspring mice

Objective:To explore whether maternal stress exposure during pregnancy impairs cognitive function and white matter ultrastructure in offspring mice.Methods:The parent rats were divided into two groups:pressure exposure group(group PE)and control group(group C),and the positive date of vaginal smear of female SD rats was day 0 of gestation.Female mice in group PE were exposed to binding pressure(3 times/day)on day 14-20 of gestation for 45 min-1 h/time.Behavioral tests(Morris water maze and Y maze)were performed on 1-month-old offspring mice followed by cardiac perfusion of fixed brain specimens and placement in mixed fixative solution.The total volume of white matter,total length and volume of myelinated nerve fibers and total length and volume of myelin sheath were calculated using modern stereoscopic methods,and the inner and outer diameter and inner and outer circumference of the myelin sheath were analyzed.Results:1)Behavioral tests:compared with the group C,the average latency of the 3th and 4th day in the group PE were significantly prolonged,the percentage of the resting time in the quadrant of the platform and the frequency of acrossing the effective area of platform in the fifth day of space exploration experiment were significantly reduced of Morris water maze test,and visiting distance,duration and numbers in novel arm significantly increased of Y-maze test(P<0.05).2)Compared with group C,the total volume of white matter,total length of myelinated nerve fibers,total volume of myelinated nerve fibers and myelin sheath in the group PE were significantly reduced(P<0.05),the inner diameter and outer diameter of myelin sheath decreased significantly(P<0.05),and the inner perimeter,outer perimeter and inner and outer perimeter differences increased significantly(P<0.05).3)There was a correlation between behavioral test results and white matter ultrastructure measurement results.Conclusions:Maternal stress exposure during pregnancy could impair the cognitive function and white matter and its ultrastructure in the offspring,and there was a correlation between decreased cognitive function and white matter damages.

Effects of surgical treatment modalities on postoperative cognitive function and delirium in elderly patients with extremely unstable hip fractures

BACKGROUND As the perioperative risk of elderly patients with extremely unstable hip fractures(EUHFs)is relatively high and therapeutic effect is not satisfactory,new therapeutic strategies need to be proposed urgently to improve the efficacy and clinical outcomes of such patients.AIM To determine the influence of two surgical treatment modalities on postoperative cognitive function(CF)and delirium in elderly patients with EUHFs.METHODS A total of 60 elderly patients consecutively diagnosed with EUHF between September 2020 and January 2022 in the Chongqing University Three Gorges Hospital were included.Of them,30 patients received conventional treatment(control group;general consultation+fracture type-guided internal fixation),and the other 30 received novel treatment(research group;perioperative multidisciplinary treatment diagnosis and treatment+individualized surgical plan+risk prediction).Information on hip function[Harris hip score(HHS)],perioperative risk of orthopedic surgery[Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity(POSSUM)],CF[Montreal cognitive assessment scale(MoCA)],postoperative delirium[mini-cognitive(Mini-Cog)],adverse events(AEs;internal fixation failure,infection,nonunion,malunion,and postoperative delirium),and clinical indicators[operation time(OT),postoperative hospital length of stay(HLOS),ambulation time,and intraoperative blood loss(IBL)]were collected from both groups for comparative analyses.RESULTS The HHS scores were similar between both groups.The POSSUM score at 6 mo after surgery was significantly lower in the research group compared with the control group,and MoCA and Mini-Cog scores were statistically higher.In addition,the overall postoperative complication rate was significantly lower in the research than in the control group,including reduced OT,postoperative HLOS,ambulation time,and IBL.CONCLUSION The new treatment modality has more clinical advantages over the conventional treatment,such as less IBL,faster functional recovery,more effectively optimized perioperative quality control,improved postoperative CF,mitigated postoperative delirium,and reduced operation-related AEs.

Comparative efficacy of various exercise interventions on cognitive function in patients with mild cognitive impairment or dementia:A systematic review and network meta-analysis

Background:Exercise is a promising nonpharmacological therapy for cognitive dysfunction,but it is unclear which type of exercise is most effective.The objective of this study was to compare and rank the effectiveness of various exercise interventions on cognitive function in patients with mild cognitive impairment(MCI)or dementia and to examine the effects of exercise on the symptoms relevant to cognitive impairment.Methods:We searched PubMed,Web of Science,Embase,Cochrane Central Register of Controlled Trials,SPORTDiscus,and PsycInfo through September 2019 and included randomized controlled trials that examined the effectiveness of exercise interventions in patients with MCI or dementia.Primary outcomes included global cognition,executive cognition,and memory cognition.Secondary outcomes included activities of daily living,neuropsychiatric symptoms,and quality of life.Pairwise analyses and network meta-analyses were performed using a random effects model.Results:A total of 73 articles from 71 trials with 5606 participants were included.All types of exercise were effective in increasing or maintaining global cognition,and resistance exercise had the highest probability of being the most effective intervention in slowing the decrease in global cognition(standard mean difference(SMD)=1.05,95%confidence interval(95%CI):0.56-1.54),executive function(SMD=0.85,95%CI:0.21-1.49),and memory function(SMD=0.32,95%CI:0.01-0.63)in patients with cognitive dysfunction.Subgroup analyses for patients with MCI revealed different effects,and multicomponent exercise was most likely to be the optimal exercise therapy for preventing the decline of global cognition(SMD=0.99,95%CI:0.44-1.54)and executive function(SMD=0.72,95%CI:0.06-1.38).However,only resistance exercise showed significant effects on memory function for patients with MCI(SMD=0.35,95%CI:0.01-0.69).Exercise interventions also showed various effects on the secondary outcomes.Conclusion:Resistance exercise has the highest probability of being the optimal exercise type for slowing cognitive declin e in patients withcognitive dysfunction,especially in patients with dementia.Multicomponent exercise tends to be most effective in protecting global cognition and executive function in patients with MCI.

Influences of Microwave on the Cognitive Function of Chickling and the Gene Expression of NMDA Receptor Subunit

[Objective] The research aimed to study the effects of microwave on the chick embryo development and the cognitive function of chickling. [Method] The microwave which was transmitted by the permatron and was 2 450 MHz was used to simulate the microwave radiation source to radiate the hatching eggs until the chickling was hatched out. The disposable passive avoidance learning and RT-PCR were respectively used to detect the influences of microwave on the cognitive function of chickling and the expression amounts of NMDA receptor NR1 and NR2 subunits. [Result] After the microwave radiation,the avoidance rate of exposed group was significantly lower than that in the control group. Especially the avoidance rate of highest radiation intensity group was extremely significantly lower than that in the control group. Meanwhile,the body weights of two groups of chickling in the exposed group increased,and the hatching time in one group increased. Via RT-PCR analysis,the expression amount of NR2 subunit increased on the 10th day and the 15th day. The expression amount of NR1 subunit only decreased on the 15th day. [Conclusion] The microwave had the certain influence on the individual development. By changing the structure composition and function of NMDA receptor in the endbrain,the microwave made the self-regulation ability of chickling decline,which had the certain damage on the cognitive function.

Extremely low frequency electromagnetic fields promote cognitive function and hippocampal neurogenesis of rats with cerebral ischemia

Extremely low frequency electromagnetic fields(ELF-EMF) can improve the learning and memory impairment of rats with Alzheimer's disease, however, its effect on cerebral ischemia remains poorly understood.In this study, we established rat models of middle cerebral artery occlusion/reperfusion.One day after modeling, a group of rats were treated with ELF-EMF(50 Hz, 1 mT) for 2 hours daily on 28 successive days.Our results showed that rats treated with ELF-EMF required shorter swimming distances and latencies in the Morris water maze test than those of untreated rats.The number of times the platform was crossed and the time spent in the target quadrant were greater than those of untreated rats.The number of BrdU~+/NeuN~+ cells, representing newly born neurons, in the hippocampal subgranular zone increased more in the treated than in untreated rats.Up-regulation in the expressions of Notch1, Hes1, and Hes5 proteins, which are the key factors of the Notch signaling pathway, was greatest in the treated rats.These findings suggest that ELF-EMF can enhance hippocampal neurogenesis of rats with cerebral ischemia, possibly by affecting the Notch signaling pathway.The study was approved by the Institutional Ethics Committee of Sichuan University, China(approval No.2019255A) on March 5, 2019.

Effects of Lipoxin A4 Pretreatment on Cognitive Function of Aged Rats after Global Cerebral Ischemia Reperfusion

The aim of the present study was to investigate the effect of lipoxin A4 （LXA4） pretreatment on cognitive function of aged rats after global cerebral ischemia reperfusion, and to explore its possible mechanism. Thirty-six aged male Sprague-Dawley rats were randomly divided into three groups （n=12 each）： sham-operation group （S group）, global cerebral ischemia reperfusion group （I/R group） and LXA4-pretreatment group （L group）. The rat model of global cerebral ischemia reperfusion was established by occlusion of the bilateral common carotid artery with hypotension. The cognitive function of rats was determined by a step-down type passive avoidance test and Morris Water Maze test on the third day after reperfusion. Rats were sacrificed after Water Maze test and the pathological changes ofhippocampal CA1 region were observed and the related inflammatory mediators were determined. As compared with S group, the escape latency in I/R group was prolonged from the first day to the fifth day, while that in L group was prolonged from the first day to the third day. The retention time in I/R group and L group in the first quadrant was shortened. The reaction time, frequency of reaction mistake and frequency of escape mistake in I/R group increased, and the latent period shortened. The frequency of escape mistake in L group increased, and the damage in the hippocampal CAI region of I/R group and L group was obvious. The levels of S-10013, TNF-α, IL-1β, IL-10 and NF-κB in I/R group and L group increased. As compared with I/R group, the escape latency in L group was shortened from the first day to the fifth day, and the retention time in the first quadrant prolonged. The reaction time, frequency of reaction mistake and frequency of escape mistake in L group decreased, and the latent period prolonged. The damage in the hippocampal CA1 region of L group was alleviated as well. The levels of S-10013, TNF-α, IL-1β and NF-κB in L group decreased, and those of IL-10 increased. It can be concluded that LXA4 pretreatment can improve the cognitive function in aged rats after global cerebral ischemia reperfusion probably by inhibiting the inflammatory reaction.

Adolescent social isolation influences cognitive function in adult rats

Adolescence is a critical period for neurodevelopment. Evidence from animal studies suggests that isolated rearing can exert negative effects on behavioral and brain development. The present study aimed to investigate the effects of adolescent social isolation on latent inhibition and brain-derived neurotrophic factor levels in the forebrain of adult rats. Male Wistar rats were randomly divided into adolescent isolation （isolated housing, 38-51 days of age） and social groups. Latent inhibition was tested at adulthood. Brain-derived neurotrophic factor levels were measured in the medial prefrontal cortex and nucleus accumbens by an enzyme-linked immunosorbent assay. Adolescent social isolation impaired latent inhibition and increased brain-derived neurotrophic factor levels in the medial prefrontal cortex of young adult rats. These data suggest that adolescent social isolation has a profound effect on cognitive function and neurotrophin levels in adult rats and may be used as an animal model of neurodevelopmental disorders.

Endogenous adult neurogenesis and cognitive function recovery following traumatic brain injury in the rat hippocampus

BACKGROUND：Endogenous neural progenitor cells play a beneficial role for cognitive recovery following traumatic brain injury.However,there are few classification-control studies aimed at varying graded brain trauma.OBJECTIVE：To observe the effects of adult endogenous neurogenesis on cognitive function repair and regeneration of neural progenitor cells following varying graded traumatic hippocampal injury to determine the significance of endogenous neurogenesis in the repair of brain injury.DESIGN,TIME AND SETTING：A randomized,controlled,animal experiment was performed at the Key Laboratory of Injuries,Variations and Regeneration of Nervous System,Tianjin Medical University General Hospital,from February to October 2009.MATERIALS：Mouse anti-rat 5-bromodeoxyuridine （BrdU） and neuronal nuclei （NeuN） monoclonal antibodies were purchased from Millipore Corporation,USA.METHODS：A total of 45 Wistar rats were randomly assigned to three groups.Mild and severe injury groups were respectively subjected to （182 ± 2） kPa and （284 ± 4） kPa lateral fluid percussion to establish models of brain injury,and the control group was subjected to surgery with no lateral fluid percussion.MAIN OUTCOME MEASURES：Cognitive function was estimated using the Morris water maze.Proliferation,survival,and differentiation of newly generated cells in the injured hippocampus were observed through the use of immunofluorescent staining.RESULTS：At 7 days post-injury,the number of BrdU＋ cells in the hippocampal dentate gyrus significantly increased in the mild and severe injury groups compared with the control group （P〈0.01）.At 61 days post-injury,the number of BrdU7NeuN＋ cells in the hippocampal dentate gyrus was significantly greater in the mild injury group compared with the severe injury and control groups （P〈 0.01）.In addition,the control group exhibited the greatest proportion of surviving cells that differentiated into mature neurons compared with the injury groups （P〈 0.01）.Moreover,at 61 days post-injury,cognitive function in rats with mild injury recovered to normal levels,whereas the severe injury group exhibited cognitive deficits （P〈 0.01）.CONCLUSION：Traumatic brain injury may be a stimulation factor for proliferation of neural progenitor cells in the adult hippocampus but severe brain trauma does not lead to an increased number of newly generated cells.Endogenous adult neurogenesis repairs neurological functions to an extent.However,recovery of neurological function remains limited following severe traumatic brain injury.

Correlation of diffusion tensor imaging and cognitive function in patients with leukoaraiosis

Conventional imaging technology does not measure white matter lesions of the brain or cognitive impairment. Diffusion tensor imaging is able to detect changes in the microstructure of white matter, and correlating vascular risk factors with cognitive dysfunction seems feasible using this technique. A total of 60 leukoaraiosis patients and 30 healthy elderly controls received diffusion tensor imaging examination to detect the average diffusion coefficient and fractional anisotropy of leukoaraiosis lesion and normal white matter. Leukoaraiosis severity positively correlated with average diffusion coefficient but negatively correlated with fraction anisotropy. Neuropsychology tests （mini-mental state examination） were related to average diffusion coefficient and fraction anisotropy of normal white matter in leukoaraiosis patients, especially in the anterior horn and centrum semiovale. The average diffusion coefficient and fraction anisotropy of leukoaraiosis displayed characteristic changes. Therefore, diffusion tensor imaging can detect the macrostructural changes in white matter with normal magnetic resonance imaging, and these changes are related to cognitive function. Application of diffusion tensor imaging techniques to analyze the correlation between vascular risk factors and cognitive dysfunction is feasible.

Does a combined intervention program of repetitive transcranial magnetic stimulation and intensive occupational therapy affect cognitive function in patients with post-stroke upper limb hemiparesis?

Low-frequency repetitive transcranial magnetic stimulation（LF-r TMS） to the contralesional hemisphere and intensive occupational therapy（i OT） have been shown to contribute to a significant improvement in upper limb hemiparesis in patients with chronic stroke. However, the effect of the combined intervention program of LF-r TMS and i OT on cognitive function is unknown. We retrospectively investigated whether the combined treatment influence patient＇s Trail-Making Test part B（TMT-B） performance, which is a group of easy and inexpensive neuropsychological tests that evaluate several cognitive functions. Twenty-five patients received 11 sessions of LF-r TMS to the contralesional hemisphere and 2 sessions of i OT per day over 15 successive days. Patients with right- and left-sided hemiparesis demonstrated significant improvements in upper limb motor function following the combined intervention program. Only patients with right-sided hemiparesis exhibited improved TMT-B performance following the combined intervention program, and there was a significant negative correlation between Fugl-Meyer Assessment scale total score change and TMT-B performance. The results indicate the possibility that LF-r TMS to the contralesional hemisphere combined with i OT improves the upper limb motor function and cognitive function of patients with right-sided hemiparesis. However, further studies are necessary to elucidate the mechanism of improved cognitive function.

Updated overview on interplay between physical exercise,neurotrophins,and cognitive function in humans

The many important benefits of physical exercise also encompass maintenance or improvement of cognitive functions. Among the variousmechanisms underlying the association between physical exercise and brain health, recent evidence attests that neurotrophin receptor signalingmay have an important role, because the activation of this pathway leads to growth and differentiation of new neurons and synapses, supportsaxonal and dendritic growth, fosters synaptic plasticity, and preserves survival of existing neurons. In this review of published evidence, we highlightthat a positive relationship exists between physical exercise and circulating brain-derived neurotrophic factor levels and that the postexercisevariation of this molecule is associated with improvement of neurocognitive functioning. Less clear evidence has instead been published forother neurotrophins, such as nerve growth factor, neurotrophin-3, and neurotrophin-4. Overall, promotion of adequate volumes and intensities ofphysical exercise (i.e., approximately 3 months of moderate-intensity aerobic exercise, with 2—3 sessions/week lasting not less than 30 min)may hence be regarded as an inexpensive and safe strategy for boosting brain-derived neurotrophic factor release, thus preserving or restoringcognitive functions.

An enriched environment reduces hippocampal inflammatory response and improves cognitive function in a mouse model of stroke

An enriched environment is used as a behavio ral intervention therapy that applies sensory,motor,and social stimulation,and has been used in basic and clinical research of va rious neurological diseases.In this study,we established mouse models of photothrombotic stroke and,24 hours later,raised them in a standard,enriched,or isolated environment for 4 weeks.Compared with the mice raised in a standard environment,the cognitive function of mice raised in an enriched environment was better and the pathological damage in the hippocampal CA1 region was remarkably alleviated.Furthermore,protein expression levels of tumor necrosis factor receptor-associated factor 6,nuclear factorκB p65,interleukin-6,and tumor necrosis factorα,and the mRNA expression level of tumor necrosis factor receptor-associated factor 6 were greatly lower,while the expression level of miR-146a-5p was higher.Compared with the mice raised in a standard environment,changes in these indices in mice raised in an isolated environment were opposite to mice raised in an enriched environment.These findings suggest that different living environments affect the hippocampal inflammatory response and cognitive function in a mouse model of stro ke.An enriched environment can improve cognitive function following stroke through up-regulation of miR-146a-5p expression and a reduction in the inflammatory response.