Taeck-Hyun Lee

Influence of prenatal noise and music on the spatial memory and neurogenesis in the hippocampus of developing rats

During the prenatal period, the development of individual is influenced by the environmental factors. In the present study, the influence of prenatal noise and music on the spatial memory and neurogenesis in the hippocampus of developing rats was investigated. The exposure to the noise during pregnancy caused growth retardation, decreased neurogenesis in the hippocampus, and impaired spatial learning ability in pups. The exposure to music during pregnancy, on the other hand, caused increased neurogenesis in the hippocampus and enhanced spatial learning ability in pups. The present study has shown the importance of the prenatal environmental conditions for the cognition and brain development.

Long-term treadmill exercise overcomes ischemia-induced apoptotic neuronal cell death in gerbils

It has been suggested that exercise may ameliorate neurologic impairment by impeding neuronal loss following various brain insults. In the present study, the effect of long-term treadmill exercise on short-term memory and apoptotic neuronal cell death in the hippocampus following transient global ischemia in gerbils was investigated. A step-down inhibitory avoidance task, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and immunohistochemistry for caspase-3 were used for this study. Ischemia was induced by occlusion of both the common carotid arteries of gerbils for 5 min. Gerbils in the exercise groups were forced to run on a treadmill for 30 min once a day for 4 consecutive weeks. The present results reveal that treadmill exercise for 4 weeks improved short-term memory by suppressing the ischemia-induced apoptotic neuronal cell death in the hippocampus. Here in this study, we show that long-term treadmill exercise for 4 weeks overcomes the ischemia-induced apoptotic neuronal cell death and thus facilitates the recovery of short-term memory impairment induced by ischemic cerebral injury.

Low Dose Radiation Overcomes Diabetes-induced Suppression of Hippocampal Neuronal Cell Proliferation in Rats

We investigated the effect of low dose radiation on diabetes induced suppression of neurogenesis in the hippocampal dentate gyrus of rat. After 0.01 Gy, 0.1 Gy, 1 Gy and 10 Gy radiation was delivered, the dentate gyrus of hippocampus of streptozotocin (STZ)-induced diabetic rats were evaluated using immunohistochemistry for 5-bromo-2-deoxyuridine (BrdU), caspase-3, and terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) staining. The number of BrdU positive cells in the non-diabetic rats, diabetic rats without radiation, diabetic rats with 0.01 Gy radiation, diabetic rats with 0.1 Gy radiation, diabetic rats with 1 Gy radiation and diabetic rats with 10 Gy radiation were 55.4±8.5/mm2, 33.3±6.4/mm2, 67.7±10.5/mm2, 66.6±10.0/mm2, 23.5±6.3/mm2and 14.3±7.2/mm2, respectively. The number of caspase-3 positive cells was 132.6±37.4/mm2, 378.6±99.1/mm2, 15.0±2.8/mm2, 57.1±16.9/mm2, 191.8±44.8/mm2and 450.4±58.3/mm2, respectively. The number of TUNEL-positive cells was 24.5±2.0/mm2, 21.7±4.0/mm2, 20.4±2.0/mm2, 18.96±2.1/mm2, 58.3±7.9/mm2, and 106.0±9.8/mm2, respectively. These results suggest low doses of radiation paradoxically improved diabetes induced neuronal cell suppression in the hippocampal dentate gyrus of rat.

Treadmill exercise alleviates chronic mild stress-induced depression in rats

Depression is a major cause of disability and one of the most common public health problems. In the present study, antidepressive effect of treadmill exercise on chronic mild stress (CMS)-induced depression in rats was investigated. For this, sucrose intake test, immunohistochemistry for 5-bromo-2′-deoxyuridine, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining, and Western blot analysis for brain-derived neurotrophic factor, cyclic adenosine monophosphate response element binding protein, and endothelial nitric oxide synthase were conducted. Following adaptation to the animal vivarium and two baseline fluid intake tests, the animals were divided into four groups: the control group, the CMS-induced depression group, the CMS-induced depression and exercise group, and the CMS-induced depression and fluoxetine-treated group. The animals in the CMS groups were exposed to the CMS conditions for 8 weeks and those in the control group were exposed to the control conditions for 8 weeks. After 4 weeks of CMS, the rats in the CMS-induced depression and exercise group were made to run on a motorized treadmill for 30 min once a day for 4 weeks. In the present results, treadmill exercise alleviated CMS-induced depressive symptoms. Treadmill exercise restored sucrose consumption, increased cell proliferation, and decreased apoptotic cell death. The present results suggest the possibility that exercise may improve symptoms of depression.

Effects of acupuncture on the intrastriatal hemorrhage-induced caspase3 expression and newly cell birth in rats.

Abstract Background: Intracerebral hemorrhage is one of the most devastating types of stroke. Caspases are essential players in apoptotic cell death both as initiators and executioners. The v-Fos FBJ murine osteosarcoma viral oncogene homolog (Fos, c-Fos) is an immediate early gene, and Fos expression is sometimes used as a marker for stimuli-induced changes in the metabolic activity of neurons. The expressions of caspase3 and Fos are enhanced with neuroregeneration and with neuronal cell death, respectively. Cells proliferation the dentate gyrus of adult rodents is enhanced by certain pathologic events as seizures and ischemic insult, and such up-regulation of cell proliferation occurring during pathologic situations is thought to be a compensatory response to lesion-induced cell death in the brain. In the present study, we investigated the effects of acupuncture on the intrastriatal hemorrhage-induced caspase3 expression in the striatum and on the Fos expression and cell proliferation in the dentate gyrus of rats. Methods: For this study, immunohistochemistry for caspase3, Fos and 5-bromo-2′-deoxyuridine (BrdU) was performed. Results: Caspase3 expression in the striatum was increased by intrastriatal hemorrhage. Fos expression and cell proliferation in the dentate gyrus of rats with intracerebral hemorrhage were also increased. Acupunctural treatment, especially at the ST36 acupoint, suppressed the intracerebral hemorrhage-induced caspase3 expression in the stratum, and it also inhibited expression of Fos and cell proliferation in the dentate gyrus. Conclusion: In the present study, we have shown that acupuncture treatment has a neuroprotective effect on intrastrstriatal hemorrhage-induced neuronal cell death, and this suggests that acupuncture can aid in the recovery of the central nervous system following stroke.

Nicotine administration increases serotonin synthesis and tryptophan hydroxylase expression in dorsal raphe of food-deprived rats

The effects of nicotine on the synthesis of serotonin (5-hydroxytryptamine; 5-HT), known to inhibit food intake, and the expression of tryptophan hydroxylase (TPH), the rate-limiting enzyme of 5-HT biosynthesis, in the dorsal raphe were investigated via immunohistochemistry. Male Sprague-Dawley rats were divided into 4 groups: the fed group, the fed and nicotine-treated group, the food-deprived group, and the food-deprived and nicotine-treated group. Food was withheld from the food-deprived groups for 72 h. Animals of the nicotine-treated groups were injected intraperitoneally with 1 mg/kg of nicotine twice per day for 3 days. The numbers of 5-HT-positive and TPH-positive cells in the dorsal raphe were decreased in food-deprived rats. Nicotine administration exerted no significant effect on the numbers of 5-HT-positive and TPH-positive cells in fed rats, while it increased those numbers in food-deprived rats. These observations suggest that smoking has a negative bearing on the augmented desire for food under food-restricted conditions.

Relationships among Obesity, Sarcopenia, and Osteoarthritis in the Elderly

Background The present study examined the correlations between obesity, sarcopenia, and osteoarthritis in Korea’s elderly population. Methods A cross-sectional analysis of 1,865 and 1,769 respondents with knee osteoarthritis and lumbar spondylosis, respectively, was performed by using data from the 2010 and 2011 Korea National Health and Nutrition Examination Survey. Obesity was defined as a body mass index of ≥25 kg/m2; osteoarthritis, as a Kellgren/Lawrence grade of ≥2; and sarcopenia, as an appendicular skeletal muscle mass (ASM; ASM/weight ×100) on dual-energy X-ray absorptiometry of two standard deviations below the mean reference value. Results The unadjusted and age-adjusted risks of knee osteoarthritis were as follows: 1.88 and 1.92 times greater, respectively, for male subjects with sarcopenic obesity; 6.03 and 7.64 times greater, respectively, for female subjects with non-sarcopenic obesity; and 1.97 and 2.43 times greater, respectively, for female subjects with sarcopenic obesity. The age-and-waist circumference-adjusted risks were 5.88 and 1.80 times greater for the female subjects with non-sarcopenic and sarcopenic obesities, respectively. No statistically significant finding was obtained for lumbar spondylosis. Conclusion Obesity and sarcopenia were associated with knee osteoarthritis in the elderly subjects. The risk of knee osteoarthritis was greater in the male subjects with sarcopenic obesity than in the male subjects with non-sarcopenic obesity. In the female subjects, the risk of knee osteoarthritis was high in both obesity groups. Further research to explain the sex-related difference in knee osteoarthritis risk based on body composition will be beneficial.

Ferritin and hemoglobin level of korean according to vitamin D state: The Korean National Health and Nutrition Examination Survey IV, V (2008~2012)

This study is designed to investigate the differences of ferritin and hemoglobin levels according to the vitamin D state in 23577 Korean adult subjects by using data from the Korea National Health and Nutrition Examination Survey IV, V. Ferritin and hemoglobin levels are analyzed based on the quintile of vitamin D levels by a generalized linear model. The results of analysis showed that there was a relationship between vitamin D state and hemoglobin levels in females in the reproductive status group (p<0.001). In case of ferritin, there was a relationship with vitamin D state in females in reproductive status group (p<0.001) and males under 65 years old group (p<0.05). Within the male group, high ferritin correlated with low vitamin D state; but in the female group, high ferritin correlated with high vitamin D state. Therefore, it is possible for the ferritin level to be affected by vitamin D state in females in reproductive status group and males under 65 years old group.

Vitamin D status and its associations with rheumatoid arthritis in Korean women: the Korean National Health and Nutrition Examination Survey 2008-2014.

In the present study, vitamin D status and its associations with rheumatoid arthritis in Korean women were investigated. Total 2,162 women’s data from the Korea National Health and Nutrition Examination Survey during 2008–2014 ware analyzed by complex sampling design logistic regression analysis and complex sampling design general linear model. Women who over 19 years old were included, and who has osteoporosis or abnormal parathyroid hormone or renal failure or liver cirrhosis or abnormal creatinine were excluded. Age and body mass index were used as covariate. In the present study, we have shown that vitamin D status were not associated with development of rheumatoid arthritis in Korean women as well were not associated with pain and quality of life in Korean women with rheumatoid arthritis. Based on the present study and considering the effects of vitamin D on fracture and osteoporosis, it can be suggested that additional cohort study and cost-effectiveness analysis are needed.