Safflower seed oil, a rich source of linoleic acid, stimulates hypothalamic neurogenesis in vivo / 대한해부학회지

Adult neurogenesis has been reported in the hypothalamus, subventricular zone and subgranular zone in the hippocamp. Recent studies indicated that new cells in the hypothalamus are affected by diet. We previously showed beneficial effects of safflower seed oil (SSO), a rich source of linoleic acid (LA; 74%), on proliferation and differentiation of neural stem cells (NSCs) in vitro. In this study, the effect of SSO on hypothalamic neurogenesis was investigated in vivo, in comparison to synthetic LA. Adult mice were treated with SSO (400 mg/kg) and pure synthetic LA (300 mg/kg), at similar concentrations of LA, for 8 weeks and then hypothalamic NSCs were cultured and subsequently used for Neurosphere-forming assay. In addition, serum levels of brain-derived neurotrophic factor (BNDF) were measured using enzyme-linked immunosorbent assay. Administration of SSO for 8 weeks in adult mice promoted the proliferation of NSCs isolated from SSO-treated mice.Immunofluorescence staining of the hypothalamus showed that the frequency of astrocytes (glial fibrillary acidic protein+ cells) are not affected by LA or SSO. However, the frequency of immature (doublecortin+ cells) and mature (neuronal nuclei+ cells) neurons significantly increased in LA- and SSO-treated mice, compared to vehicle. Furthermore, both LA and SSO caused a significant increase in the serum levels of BDNF. Importantly, SSO acted more potently than LA in all experiments.The presence of other fatty acids in SSO, such as oleic acid and palmitic acid, suggests that they could be responsible for SSO positive effect on hypothalamic proliferation and neurogenesis, compared to synthetic LA at similar concentrations.

Effects of radiofrequency exposure emitted from a GSM mobile phone on proliferation, differentiation, and apoptosis of neural stem cells / 대한해부학회지

Due to the importance of neural stem cells (NSCs) in plasticity of the nervous system and treating neurodegenerative diseases, the main goal of this study was to evaluate the effects of radiofrequency radiation emitted from a GSM 900-MHz mobile phone with different exposure duration on proliferation, differentiation and apoptosis of adult murine NSCs in vitro. We used neurosphere assay to evaluate NSCs proliferation, and immunofluorescence assay of neural cell markers to examine NSCs differentiation. We also employed alamarBlue and caspase 3 apoptosis assays to assess harmful effects of mobile phone on NSCs. Our results showed that the number and size of resulting neurospheres and also the percentage of cells differentiated into neurons decreased significantly with increasing exposure duration to GSM 900-MHz radiofrequency (RF)-electromagnetic field (EMF). In contrast, exposure to GSM 900-MHz RF-EMF at different durations did not influence cell viability and apoptosis of NSCs and also their astrocytic differentiation. It is concluded that accumulating dose of GSM 900-MHz RF-EMF might have devastating effects on NSCs proliferation and neurogenesis requiring more causations in terms of using mobile devices.

The effects of repetitive transcranial magnetic stimulation on proliferation and differentiation of neural stem cells / 대한해부학회지

Repetitive transcranial magnetic stimulation (rTMS) is a new method for treating many neurological conditions; however, the exact therapeutic mechanisms behind rTMS-induced plasticity are still unknown. Neural stem and progenitor cells (NS/PCs) are active players in brain regeneration and plasticity but their behavior in the context of rTMS therapy needs further elucidation. We aimed to evaluate the effects of rTMS on proliferation and differentiation of NS/PCs in the subventricular zone (SVZ) of adult mouse brain. Adult male mice (n=30) were divided into rTMS (1-Hz and 30-Hz) and sham groups and treated for 7 or 14 consecutive days. Harvested NS/PCs from the SVZ were cultured in the neurosphere assay for 8 days and the number and size of the resulting neurospheres as well as their in vitro differentiation capacity were evaluated. After one week of rTMS treatment at 1-Hz and 30-Hz compared with sham stimulation, the mean neurosphere forming frequency per brain was not different while this measure significantly increased after two weeks (P<0.05). The mean neurosphere diameter in 1-Hz treatment paradigm was significantly larger compared with sham stimulation at both 1 and 2 weeks. In contrast, 30-Hz treatment paradigm resulted in significantly larger neurospheres only after 2 weeks. Importantly, rTMS treatment at both frequencies increased neuronal differentiation of the harvested NS/PCs. Furthermore, one week in vitro rTMS treatment of NS/PCs with both 1-Hz and 30-Hz increased NS/PCs proliferation and neuronal differentiation. It is concluded that both 1-Hz and 30-Hz rTMS treatment increase NS/PCs proliferation and neuronal differentiation.

Effects of aerobic exercise on lung function in overweight and obese students

In healthy teenagers, obesity and physical inactivity are the two main factors that affect respiratory function. The aim of this study was to evaluate the effect of aerobic exercise training on improving lung function in overweight and obese students. Thirty overweight or obese subjects with poor endurance performance and mild deterioration of respiratory indices [forced expiratory volume and forced expiratory volume in 1 second < 90% predicted] were randomly assigned into control [age: 16.6 +/- 0.83 years, height: 167 +/- 5.05 cm, weight: 80.44 +/- 7.65 kg] and intervention groups [age: 16.5 +/- 0.83 years, height: 166 +/- 6.7 cm, weight: 79.62 +/- 9.33 kg] .The intervention group preformed 24 weeks of continuous treadmill running [3 days a week]. Respiratory indices were measured pre, mid and post exercise. Independent t test, paired t test, Pearson's correlation test and repeated measure were used for analyzing the data. In the intervention group, post exercise respiratory indices were significantly higher than the pre exercise values, and did not reach the predicted values. No significant differences were found in pre, mid and post exercise respiratory indices in the control group. In the intervention group, improvements in respiratory indices were positively correlated with maximum voluntary ventilation [MVV] improvement but not with BMI reduction. No significant differences were detected between the 2 groups in terms of pre, mid and post exercise measures of BMI, weight, height, and respiratory indices. In overweight and obese teenagers, appropriate aerobic exercise training can partly improve lung function by strengthening the muscles of respiration. However, in order to achieve the predicted values of lung function, a further increase in activity duration and decrease in BMI is necessary