Adult hippocampal neurogenesis: A possible way how physical exercise counteracts stress

It was considered that neurogenesis only occurred during the embryonic and developmental stage. This view has greatly changed since the discovery of adult neurogenesis in two brain regions: the hippocampus and the olfactory bulb. Recently, it is suggested that altered hippocampal neurogenesis is related to pathophysiology of mood disorders and mechanism of antidepressant treatments. Accumulating knowledge about the effects of physical exercise on brain function suggests a special role of adult hippocampal neurogenesis in cognitive and mental health, even though the functional significance of adult neurogenesis is still debated. The beneficial effects of running correlating with increased adult neurogenesis may provide a hint that newborn neurons may be involved, at least in part, in the counteractive mechanism of physical exercise on stress-related disorders, like depression. The present review provides an overview of recent findings to emphasize the possible involvement of hippocampal neurogenesis in mediating the beneficial effects of physical exercise on counteracting stress. Copyright © 2011 Cognizant Comm. Corp.published_or_final_versio

Neurogenic hypothesis and psychiatric disorders

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Construct validity of the short forms child perceptions questionnaire (CPQ11-14)

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Evaluation of child perceptions questionnaire (CPQ11-14) using structural equation modeling

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Differential behavioral outcome of anxiety tests in runner rats treated with corticosterone

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Voluntary wheel running reverses the decrease in subventricular zone neurogenesis caused by corticosterone

Adult neurogenesis within the dentate gyrus of the hippocampus can be increased by voluntary exercise but is suppressed under stress, such as with corticosterone (CORT). However, the effects of exercise and corticosterone on the cell proliferation of the other traditional neurogenic site, the subventricular zone (SVZ) have been reported with controversial results. In addition, the co-treatment effects of voluntary exercise and corticosterone have not been investigated. This study aims to determine whether corticosterone can suppress cell proliferation in the SVZ, and whether this can be reversed by voluntary exercise. In the present study, the effect of chronic (4 weeks) corticosterone treatment and wheel running simultaneously on the SVZ cell proliferation of adult Sprague-Dawley rats was examined. The results showed that cell proliferation indicated by bromodeoxyuridine (BrdU) was increased by voluntary wheel running whereas it was decreased by corticosterone treatment within the SVZ of the rats without running. For the rats with both corticosterone treatment and wheel running, it was found that the number of BrdU-labeled cells was approximately at the same level as the vehicle control group. Furthermore, these proliferating cells expressed doublecortin (DCX), a migrating neuroblast marker. Wheel running increased the percentage of BrdU-labeled cells expressing DCX in the SVZ whereas corticosterone treatment decreased this percentage. Thus, chronic injection of corticosterone can decrease the number of proliferating cells while wheel running can reverse the decrease in cell proliferation within the SVZ to normal levels. In addition, corticosterone can suppress the cell differentiation within the SVZ and this was alleviated by wheel running as indicated by the double-labeling of BrdU and DCX.published_or_final_versio

Lycium barbarum (wolfberry) polysaccharide facilitates ejaculatory behaviour in male rats

Poster Session AOBJECTIVE: Lycium barbarum (wolfberry) is a traditional Chinese medicine, which has been considered to have therapeutic effect on male infertility. However, there is a lack of studies support the claims. We thus investigated the effect of Lycium barbarum polysaccharide (LBP), a major component of wolfberry, on male rat copulatory behavior. METHOD: Sprague-Dawley rats were divided into two groups (n=8 for each group). The first group received oral feeding of LBP at dosage of 1mg/kg daily. The control group received vehicle (0.01M phosphate-buffered saline, served as control) feeding daily for 21 days. Copulatory tests were conducted at 7, 14 and 21 days after initiation of treatment. RESULTS: Compared to control animals, animals fed with 1mg/kg LBP showed improved copulatory behavior in terms of: 1. Higher copulatory efficiency (i.e. higher frequency to show intromission rather than mounting during the test), 2. higher ejaculation frequency and 3. Shorter ejaculation latency. The differences were found at all time points (Analyzed with two-tailed student’s t-test, p<0.05). There is no significant difference found between the two groups in terms of mount/intromission latency, which indicates no difference in time required for initiation of sexual activity. Additionally, no difference in mount frequency and intromission frequency was found. CONCLUSION: The present study provides scientific evidence for the traditional use of Lycium barbarum on male sexual behavior. The result provides basis for further study of wolfberry on sexual functioning and its use as an alternative treatment in reproductive medicine.postprintThe 30th Annual Meeting of the Australian Neuroscience Society, in conjunction with the 50th Anniversary Meeting of the Australian Physiological Society (ANS/AuPS 2010), Sydney, Australia, 31 January-3 February 2010. In Abstract Book of ANS/AuPS, 2010, p. 177, abstract no. POS-TUE-19

Executive function in patients with obstructive sleep apnea treated with continuous positive airway pressure

Obstructive sleep apnea (OSA) is characterized by disrupted breathing and hypoxemia during sleep, daytime sleepiness, and changes in cognition and mood. One important question is regarding the reversibility of cognitive deficits after treatment with continuous positive airway pressure (CPAP). Here, we report the outcomes of CPAP treatment as measured by tests of attention and executive function. Thirty-seven individuals with moderate to severe OSA and compliant on CPAP treatment were studied with working memory tasks, neuropsychological testing, and overnight polysomnographic sleep study and compared to 27 healthy controls. CPAP improved the respiratory disturbance index, minimum and mean oxygen saturation (SpO2), subjective sleep quality, and daytime sleepiness ratings compared to pre-treatment values. In terms of current neurocognitive function, treated individuals with OSA performed at a comparable level to controls on basic working memory storage functions but still showed a significant reduction on tests of working memory requiring the central executive. The OSA group also performed worse on neuropsychological measures of complex attention, executive function, and psychomotor speed. While CPAP is an effective treatment for OSA in terms of ameliorating breathing disruption and oxygen desaturation during sleep, as well as daytime sleepiness, some cognitive deficits may be more resistant to treatment. (JINS, 2010, 16, 1077-1088.) Copyright © The International Neuropsychological Society 2010.published_or_final_versio

The Role of Daytime Sleepiness in Psychosocial Outcomes after Treatment for Obstructive Sleep Apnea

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Effects of the integrative mind-body intervention on depression, sleep disturbances and plasma IL-6

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