The effects of exercise on the expression of ferroptosis-related proteins in mice with post-traumatic stress disorder / 神经解剖学杂志

Objective:The study aimed to investigate the effects of exercise on the expression of ferroptosis-related proteins and the associated mechanisms in a post-traumatic stress disorder(PTSD)model induced by transient foot shock.Methods:Thirty-five male C57BL/6J mice(8 weeks old)were randomly divided into three groups:Control group,PTSD group,and Exe+PTSD group.PTSD model mice were established by foot-shock and PTSD behaviors were assessed using a fear conditioning box.Iron distribution areas were detected by Fe3+staining.Western Blot analysis were performed to determine the expression level of ferroptosis-related proteins in the mice.Results:Compared to the control group,the freezing time and Fe3+distribution areas in the cortex and hippocampus were significantly increased in the mice with PTSD(P＜0.05).The levels of ferroportin1(FPN1),glutathione peroxidase 4(GPX4),and brain-derived neurotrophic factor(BDNF)proteins were significantly decreased(P＜0.05),while the expression of high mobility group box 1(HMGB1)protein was significantly elevated(P＜0.05).Exercise significantly reduced freezing time and Fe3+accumulation in the cortex and hippocampus(P＜0.05),and it also up-regulated the expression of FPN1,GPX4,and BDNF proteins(P＜0.05),while down-regulating HMGB1 expression compared to the PTSD group(P＜0.05).Conclusion:This study demonstrates that PTSD induces the ferroptosis-related pathway in mice,and exercise can inhibit iron accumulation and reverse the expression of ferroptosis-related proteins induced by PTSD,there-by alleviating PTSD-like behavior in mice.

An Infrared Touch System for Automatic Behavior Monitoring / 神经科学通报·英文版

Key requirements of successful animal behavior research in the laboratory are robustness, objectivity, and high throughput, which apply to both the recording and analysis of behavior. Many automatic methods of monitoring animal behavior meet these requirements. However, they usually depend on high-performing hardware and sophisticated software, which may be expensive. Here, we describe an automatic infrared behavior-monitor (AIBM) system based on an infrared touchscreen frame. Using this, animal positions can be recorded and used for further behavioral analysis by any PC supporting touch events. This system detects animal behavior in real time and gives closed-loop feedback using relatively low computing resources and simple algorithms. The AIBM system automatically records and analyzes multiple types of animal behavior in a highly efficient, unbiased, and low-cost manner.

Efecto de la adrenomedulina cerebelosa frente al estrés agudo / Effect of cerebellar adrenomedullin during acute stress

La adrenomedulina (AM) es un péptido involucrado en la regulación cardiovascular. En el cerebelo, la densidad de los receptores de la AM se encuentra alterada durante la hipertensión, sugiriendo un posible papel del sistema adrenomedulinérgico cerebelar en la regulación de la presión arterial (PA). El objetivo del presente estudio fue evaluar el efecto funcional in vivo de la AM durante el estrés agudo, mediante la administración in situ de AM en el vermis cerebelar de la rata. Se emplearon ratas adultas normotensas Wistar Kyoto (WKY) y Sprague Dawley (SD) y ratas espontáneamente hipertensas (SHR) las cuales fueron anestesiadas y posteriormente canuladas en el vermis cerebelar. El estrés se indujo mediante el uso del estímulo eléctrico plantar (EEP). Los animales fueron divididos en grupos que recibieron AM (0,2 o 200 pmol/5μL) o vehículo (solución fisiológica, 5μL). La PA se determinó antes del experimento y después de la administración del tratamiento respectivo, seguida de la aplicación del EEP (100 V, 5 Hz, 10 mseg, durante 4 minutos). La PA se determinó mediante pletismografía digital no invasiva. Los resultados demuestran que la microinyección de AM (0,2 y 200 pmol) in situ en el vermis cerebeloso en ratas SD, WKY y SHR disminuye significativamente la respuesta presora frente al estrés inducido por el EEP, lo que sugiere que la acción hipotensora está mediada a través de la regulación del eflujo simpático. Estos hallazgos demuestran la participación de la AM cerebelosa en la regulación de la respuesta cardiovascu lar frente al estrés.

Adrenomedullin (AM) is a peptide involved in cardiovascular regulation. In the cerebellum, the density of AM receptors is altered during hypertension, suggesting a pos sible role of cerebellar adrenomedulinergic system in the regulation of blood pressure (BP). The aim of this study was to evaluate the functional role of AM during acute stress, by in situ administration of AM into the cerebellar vermis in rats. Adult normotensive Wistar Kyoto (WKY) and Sprague Dawley (SD) rats and spontaneously hypertensive rats (SHR), were anes thetized and their cerebellar vermis cannulated. Footshock was used as stressor. Animals were divided into groups that received either AM (0.2 and 200 pmol/5μL) or vehicle (physiological saline, 5μL). The BP was determined, using noninvasive digital plethysmography, before and after treatment, followed by footshock (100V, 5 Hz, 10 msec, for 4 minutes). The results show that microinjection of AM (0.2 and 200 pmol) in situ into the cerebellar vermis in SD, WKY and SHR rats, significantly decreased the pressor response induced by footshock stress, sugges ting that the hypotensive action is mediated through regulation of sympathetic outflow. Taken together, our results demonstrate a role of cerebellar AM in the regulation of cardiovascular response to stress.

A novel fear conditioning memory model formation and erasing by foot-shock in tree shrew / 安徽医科大学学报

Objective To investigate the way of fear conditioning memory model evoked and erased by foot-shock in tree shrew. Methods First, detect the tree shrew activities regularly in light/dark box. Second, test a suitable voltage degree of foot shock on tree shrew. Third, investigate the memory formation and erasing of fear conditioning on tree shrew of trial group. Results The duration of tree shrew (n=4) stay in the dark-box was significantly lon-ger than that of in the light box (P<0. 01) in normal condition. In the same environment of two light boxes, given different voltage degrees, the durations of tree shrew (n=6) stay in the stimulating chamber gradually reduced and the durations of tree shrew stay had significant difference between stimulatus chamber and no stimulatus chamber when the stimulus voltage up to 12 V ( P<0. 05 ) , 16 V ( P<0. 01 ) and 20 V ( P<0. 01 ) . The animal of trial group ( n=4 ) could build up the fear conditioning memory of the dark box with the stimulus of 16 V foot-shock in the dark box ( P<0. 001 ) . After formation of the fear conditioning memory, the same stimulus in light box ap-peared for 4 days. The durations of tree shrew stay in trial group (n=4) decreased in light box, and there was no significant difference between the trial group and the control group. Conclusion Tree shrew prefers to stay in the dark box. The suitable voltage for foot-shock on tree shrew is 16 V. The fear conditioning memory can be evoked and erased by foot-shock.

Effects of exposure conditions to footshocks early in life on spontaneous locomotor activity at maturity in rats

Both genetic and environmental factors are involved in establishing a behavior. An animal study was done to determine the characteristics of interaction between genetic (nature) and environmental (nurture) factors. Delivery of footshocks (0.8 mA x 60 times, at random) early in life was used as the environmental stimulus. As the footshock was delivered repeatedly, a rat showed helplessness behavior and the number of shocks necessary to elicit helplessness was measured to quantify the trait of an animal in coping with the aversive environmental stimulus. The nocturnal ambulatory activity at adulthood was measured as a behavioral expression of the nature-nurture interaction. Although the experience of footshocks early in life did not significantly alter average activity levels at adulthood, the activity was positively correlated with the number of shocks necessary to elicit helplessness (nature) while receiving footshocks (nurture) on postnatal day 14. Additionally, a second exposure to identical shock parameters on postnatal day 21 reversed the relationship. These results clearly showed that an interaction between nature and nurture during infancy leads to substantial behavioral alterations later in life, and suggest that the nature-dependent determination of an adult behavior can be modified in different directions by the conditions of an environmental experience early in life.

Effects of neonatal footshock stress on glucocorticoid and 5-HT2A/2C receptor bindings and exploratory behavior

To investigate the effects of neonatal stress on behavior and neurochemistry, rats were exposed to the footshock stress on postnatal day (PND) 14 or PNDs 14 and 21. Rats were exposed to uncontrollable electric shocks delivered to the floor with a constant current (0.8 mA) for 5 sec period. Daily sessions consisted of 60 trials on a random time schedule with an average of 55 sec. The first exposure to footshocks on PND 14 decreased body weight gain for 1 day. However, the second exposure to footshocks on PND 21 did not affect body weight gain. Exploratory activity was measured by exposing a rat to a novel environment 24 h after experience of footshocks. Similar to the body weight changes, a decreased activity was noted after the first exposure to footshocks, while no changed activity was noted after the second exposure to footshocks. However, the Bmax value of 5-HT2A/2C receptors in the cortex decreased by the second exposure to footshocks, but not by the first exposure to footshocks. Moreover, an autoradiographic study revealed that the density of (3H)dexamethasone binding in hippocampus decreased in rats exposed to footshocks 4 times during PND 14~20. These results suggest that the uncontrollable footshock stress changes 5-hydroxytryptamine and glucocorticoid receptor systems acutely and that the repeated exposure to the same stress may not elicit behavioral alterations by the compensatory activity of young brain although changes in some neurochemistry exist.

Effects of Foot-shock, Cold and Scalding on Dynorphin B Neurons in Rat Hypothalamus / 第二军医大学学报

With the immunocytochemical PAP-floating method we studied the effects of foot-shock, cold and scalding on Dynorphin B (Dyn B) neurons in the rat hypothalamus. The results showed that in the foot-shock condition, the anteroposterior diameter of PVH (paraventricular nucleus of hypothalamus) and PVM (paraventricular nucleus of hypothalamus, medial part) with Dyn B neurons, the total number of Dyn B neurons in PVH and the number of thick fibers in SON (supraoptic nucleus) and PVH were increased obviously; in the cold condition there was declining tendency of the total number of Dyn B neurons in PVH; and in the scalding condition the staining density of median eminence was much deeper than that in normal condition. These results imply that Dyn B neurons in the rat hypothalamus is associated with these stress responses.