Antidepressant-like effect of magnetic resonance imaging-based stimulation in mice

INTRODUCTION: It has been reported that a novel type of magnetic resonance imaging (MRI) scan called echo planar magnetic resonance spectroscopic imaging (EP-MRSI) may show antidepressant effects. We examined whether the two routine diagnostic protocols of MRI [T1 and echo planar diffusion weighted imaging (EPI-DWI)], have antidepressant-like effects in an animal model of depression. METHODS: The effects of standard EPI-DWI and T1 MRI on immobility, swimming and climbing times in the modified forced swimming test (FST) in mice were examined. After exposure to the first session of modified forced swimming test, we randomly divided the mice into four groups. The first group (T1 MRI group, n=21) received a 15-minute stimulation of T1 sequence. The second group (EPI-DWI MRI group, n=21) received a 15-minute stimulation of EPI-DWI protocol. The third group (sham group, n=21) spent 15 min in a tunnel similar to the MRI gantry in terms of size, temperature and light intensity and received recorded sounds from a normal session of EPI-DWI with similar duration and intensity. The fourth group acted as controls (n=21).The second session of the modified FST was conducted twelve hours later. The mean of immobility, swimming and climbing times in this session were compared to the control group. RESULTS: T1 weighted and EPI-DWI MRI groups showed a reduction in immobility time compared to the control group (P value<0.002, P value<0.017 respectively). This effect is comparable to that seen in the FST after the administration of antidepressant agents. The climbing time in the group subjected to EPI-DWI MRI was longer than the control group (P value<0.035). Previous studies showed similar effects after the administration of antidepressant drugs affecting the catecholamine systems. The swimming time in the T1 MRI group was significantly longer than the control group (P value<0.037). Previous studies showed qualitatively similar effect to that of anti-depressant drugs affecting the serotoninergic systems. The swimming, climbing and immobility times in the sham and control groups showed no significant difference. CONCLUSIONS: Our findings raise the possibility that MRI-based stimulation may have antidepressant-like effects in mice. This is likely to be through different mechanisms in T1 weighted and EPI-DWI protocols. However the possible biological basis of this effect is not yet understood and we would advocate further studies of MRI-based stimulation effects on transmitters in the different organs in the body specially the brain.     

Hypocretin/Orexin: a molecular link between sleep, energy regulation, and pleasure

Hypocretin (Hcrt) is a neurotransmitter of the dorsal and lateral hypothalamus that regulates sleep, appetite, and energy consumption. Recent evidence indicates that it is also involved in pleasure/reward-seeking. Mutation of the Hcrt-receptor gene causes narcolepsy in canines, and Hcrt knockout mice exhibit narcolepsy-like symptoms. Human narcoleptics do not commonly have mutations in the ligand or receptor but do have degeneration of Hcrt-containing neurons, possibly through an autoimmune mechanism. When Hcrt neurons degenerate in mice, hypophagia and obesity are observed, symptoms that are also present in some human narcoleptics. This article reviews the recent literature with regard to the many functions of this single molecule. The authors suggest that eating habits and impulsivity may be topics worth exploring in the evaluation of narcoleptic patients.     

Antioxidant and antiglycating activities of Salvia sahendica and its protective effect against oxidative stress in neuron-like PC12 cells

Increased oxidative stress is widely accepted to be a factor in the development and progression of Alzheimer's disease (AD). Here we introduced Salvia sahendica as a protective agent in differentiated PC12 cells, which are commonly considered to be a reliable model of neuronal cells. Our results demonstrated that S. sahendica has antioxidant and antiglycating properties in in vitro system and these properties are expanded into H(2)O(2)-induced model. S. sahendica inhibited H(2)O(2)-induced cell death in PC12 cells. We further showed that this plant exerts its protective effect by increasing superoxide dismutase and catalase levels, reducing lipid peroxidation and upregulating hemoxygenase-1 and glutamylcysteine synthetase proteins. This study raises the possibility of developing S. sahendica as a potential neuroprotective agent.     

Do preoperative cutaneous bleeding time tests predict the outcome of intraoral surgical bleeding?

Purpose : To determine whether cutaneous bleeding time (BT) is related to perioperative bleeding outcome measures after tooth extraction. To determine whether this investigation is reliable to predict bleeding outcome after an intraoral surgical procedure. Methods : A prospective clinical pilot study of 30 subjects. Cutaneous BT was evaluated before tooth extraction. After extraction, an oral BT was determined. Subjects were contacted 2–5 hours after extraction to assess further post operative bleeding. Results : The mean cutaneous BT was 2.3 minutes (range 1.5‐3.5). The mean oral BT was 9.1 (range 7–12). Cutaneous BT did not correlate with oral BT or any other measures of prospective bleeding. However, the time necessary for extraction correlated with extraction site bleeding 2–5 hours after surgery. Conclusion : There was no relationship between cutaneous and oral post extraction BT. The use of BT test as a screening procedure is unnecessary for prediction of prolonged bleeding after tooth extraction or minor surgical procedures in the present situation.     

Components separation: a solution to complex abdominal wall defects

Complex abdominal wall hernias can be challenging to treat. The purpose of this study was to retrospectively review the results of components separation. Seventeen patients underwent components separation between 2000 and 2007. Mean size of the hernia defect was 318 cm2. Mean number of prior abdominal operations/patient was 3.2. Nine patients (53%) had prior failed repair. At time of components separation, five patients (29%) had concurrent gastrointestinal operations and two (12%) had panniculectomy. Mean hospitalization stay was 3.8 days with a readmission rate of 41 per cent. The most common postoperative complications were wound related and occurred in 35 per cent of patients. During a mean follow-up of 21 months, only one patient had recurrent hernia (6%). Five patients (29%) required additional operations. Components separation is a viable option for patients with complex abdominal wall defects. Long-term recurrence is rare but wound related complications, operative reinterventions, and hospital readmission are common.