Dopamine D2 receptor may be involved in the regulation of cortical-striatum synaptic transmission and autonomic activity in PD mice by exercise / 生理学报

The aim of the present study was to reveal the role of cortical-striatum postsynaptic dopamine D2 receptor (D2R) in improving motor behavioral dysfunction in Parkinson's disease (PD) mice by exercise. C57/BL6 male adult mice were randomly divided into control, PD and PD plus exercise groups. The mice were injected with 6-OHDA in striatum to establish a unilateral injury PD model. The exercise intervention program was uniform speed running (16 m/min, 40 min/d, 5 d per week for 4 weeks). Autonomic activity of mice was tested by open field test. Cortical-striatum synaptic transmission efficiency was assessed by peak amplitude of field excitatory postsynaptic potential (fEPSP) recorded from in vitro brain slides. Meanwhile, the effects of D2R agonist on autonomic activity and cortical-striatal synaptic transmission were observed. The results showed that, compared with PD group, PD plus exercise group exhibited significantly increased autonomic motor distance and proportion of fast-moving (P < 0.05), as well as decreased maximum amplitude of fEPSP under increasing stimulation intensity (0.75-3.00 pA) (P < 0.05) and slope of stimulus-response curve. Compared with PD mice without D2R agonist, the movement distance and rapid movement ratio of PD mice treated with D2R agonist were increased significantly (P < 0.05), whereas fEPSP peak amplitude (P < 0.05) and the slope of stimulus-response curve were decreased. These results indicate that either early exercise intervention or D2R agonist treatment can inhibit the abnormal increase of cortical-striatum synaptic transmission and improve the autonomic motor ability in PD mice, suggesting that the cortical-striatum synaptic D2R may be an important molecular target for exercise to improve the autonomic motor ability of PD mice.

Exercise intervention improves motor symptoms of Parkinson disease and underlying mechanisms / 中国病理生理杂志

Parkinson disease(PD)is one of the most common neurodegenerative diseases in the world.Many PD treatment programs are designed to manage motor symptoms by drug or surgical intervention(such as deep brain stimu-lation).Although these regimens improve the symptoms of PD or slow the development of the disease,certain side effects remain unsolved during the treartment,and lack of neuroprotective strategies is still the main problem.Exercise or physical exercise can reduce the risk of PD,and significantly improve the movement symptoms of PD or slow down the development of the disease through different neurobiological mechanisms.This article intends to review the progress in improving the movement symptoms of PD and the possible mechanism of exercise intervention for PD.

Changes of subthalamic nucleus and cortex activity in rat during exhausting exercise / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the modulatory effect of subthalamic nucleus (STN) on activity of motor cortex during exhausting exercise.</p><p><b>METHODS</b>Electrocorticogram (ECoG) and local field potentials (LFPs) recording techniques were applied simultaneously to observe the dynamic changes of oscillations in sensorimotor area and STN of rat during exhausting exercise.</p><p><b>RESULTS</b>Rats ran well initiatively with treadmill at the beginning of the exercise, about 45 min (45 +/- 11.5) later, movement capacity reduced. Corresponding electrical property showed that STN activity increased significantly while activity of cortex decreased significantly. Subsequently rats continued exercise with minor external stimulation utill exhaustion. Activity of ECoG reached the minimum under exhausting stations (P < 0.01), while the activity of LFPs changed insignificantly (P > 0.05).</p><p><b>CONCLUSION</b>During the exhausting exercise, the cortex activity was extensively depressed with the development of fatigue, while the activity of STN increased significantly at the early stage of fatigue, STN took part in the modulation of central fatigue through negative induction. And the increase of STN activity may be one of the key measures accounting for protective inhibition.</p>

Dynamic changes of 5-HT, DA and their metabolin in rat striatum during exhaustive exercise and recovery / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the dynamic characteristics of serotonin (5-HT), dopamine (DA) and their metabolin changes in brain during the development of exercise-induced central fatigue.</p><p><b>METHODS</b>Coupling of microdialysis and capillary electrophoresis-laser induced fluorescence detection method were used to continuously monitored the changes of DA, tryptophan (Trp), tyrosine (Tyr), 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) in striatum extracellular fluid during the exhaustive exercise and recovery time.</p><p><b>RESULTS</b>The concentrations of Trp, 5-HT, 5-HIAA in striatum extracellular fluid had no remarkable changes in the early time of exercise (P < 0.05), while they significantly increased during the later time of exercise and whole recovery time (P < 0.05, P < 0.01). The concentrations of DA and Tyr significantly increased over basal level in the later exercise time, exhaust and recovery time (P < 0.05, P < 0.01). DA/5-HT significantly increased in the initial time of exercise (P < 0.05, P < 0.01), while decreased during the later exercise time, the nadir occurred at 15 minutes before rats exhausted. DA/5-HT slightly recovered back to basal level during the recovery time, and there was no significant difference during later exercise, exhausted and recovery time compared with basal level (P < 0.05).</p><p><b>CONCLUSION</b>The changes of DA and 5-HT in striatum have phase characteristics. Both of them significantly increase during the development of exercise-induced fatigue. However, the 5-HT plays the dominant role in the dynamic changes of them.</p>