Treadmill exercise ameliorates intracerebral hemorrhage-induced depression in rats

Potential effect of physical exercise on the downregulation of BDNF mRNA expression in rat hippocampus following intracerebral hemorrhage

OBJECTIVES

Physical exercise is known to induce expression of the neuroprotective brain derived neurotrophic factor (BDNF) in the hippocampus. This study examined the effects of physical exercise on hippocampal BDNF expression and the potential benefits for preventing remote secondary hippocampal damage and neurological impairment following intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

Wistar rats were randomly assigned to sham-operated, ICH, and ICH followed by exercise (ICH/Ex) groups. The two ICH groups were injected with type IV collagenase into the left basal ganglia, while sham animals were injected with equal-volume saline. The ICH/Ex group rats ran on a treadmill at 11 m/min for 30 min/day from day 3 to 16 post-ICH. All animals were examined for neurological function on day 2 pretreatment and from day 3 to 15 posttreatment, for spontaneous motor activity in the open field on day 15, and for cognitive ability using the object location test on day 16. Animals were then euthanized and bilateral hippocampi collected for gene expression analyses.

RESULTS

Experimental ICH induced neurological deficits that were not reversed by exercise. In contrast, ICH did not alter spontaneous activity or object location ability. Expression of BDNF mRNA of the ICH group was significantly downregulated in the ipsilateral hippocampus compared to the SHAM group, but this downregulation was not shown in the ICH/Ex group. The ICH/Ex group showed the downregulation of caspase-3 mRNA expression in the contralateral hippocampus compared to the SHAM group, while neither ICH nor exercise influenced toll-like receptor 4 mRNA expression.

CONCLUSIONS

ICH induced the secondary BDNF downregulation in the hippocampus remote from the lesion, whereas physical exercise might partially mitigate the downregulation.

CHANGES IN THE SENSORIMOTOR CORTEX OF THE RAT BRAIN UNDER THE MODELING OF HEMORRHAGIC STROKE

OBJECTIVE

The aim: To assess the structural and metabolic changes in the sensorimotor cortex of the rat brain under conditions of hemorrhagic stroke.

PATIENTS AND METHODS

Materials and methods: The experiment was carried out on rats of the control and experimental groups with a model of hemorrhagic stroke. We used histological, electron microscopic, biochemical methods and biological markers.

RESULTS

Results: In the sensorimotor cortex of the ipsilateral cerebral hemisphere of rats under conditions of hemorrhagic stroke, cerebral edema and progression of neurodegenerative changes were observed; an increase in the size of mitochondria, which is caused by edema of their matrix; activation of lipid peroxidation processes and a decrease in the activity of enzymes of the antioxidant system, a decrease in the level of apoptosis markers and inhibition of ERK1/2 expression. The study of DNA fragmentation in the cerebral cortex revealed a significant number of manifestations of necrosis and an insignificant number of cells in a state of apoptosis.

CONCLUSION

Conclusions: after modelling a hemorrhagic stroke in the right hemisphere of the brain, perivascular and pericellular edema of the energy apparatus, cell death by necrosis and apoptosis, and activation of lipid peroxidation processes were established as well as a decrease in the activity of enzymes of the antioxidant system.

Neuroprotective efficacy of 4-Hydroxyisoleucine in experimentally induced intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a severe form of brain injury, which is a major cause of mortality in humans. Hydrocephalus and cerebral hematoma lead to severe neurological deficits. A single autologous blood (ALB) injection in rats' brains induces hemorrhage and other conditions that regularly interfere with the standard treatment of several cellular and molecular pathways. Several studies have found that IGF-1/GLP-1 decreases the production of inflammatory markers in peripheral tissues, while some have found that they also have pro-inflammatory functions. Since these receptors are down-regulated in hemorrhagic situations, we looked into the potential neuroprotective effect of 4-hydroxyisoleucine (4-HI); 50 mg/kg and 100 mg/kg, an active compound Trigonellafoenum-graecum, on post-hemorrhagic deficits in rats. Long-term oral administration of 4-HI for 35 days has improved behavioral and neurochemical deficits and severe pathological changes and improved cellular and molecular markers, apoptotic markers in the ALB-induced ICH experimental model.

Furthermore, the findings revealed that 4-HI also improved the levels of other neurotransmitters (Ach, DOPA, GABA, glutamate); inflammatory cytokines (TNF-alpha, IL-1β, IL-17), and oxidative stress markers (MDA, nitrite, LDH, AchE, SOD, CAT, GPx, GSH) in the brain when evaluated after Day 35. There is no proven treatment available for the prevention of post-brain hemorrhage and neurochemical malfunction; available therapy is only for symptomatic relief of the patient. Thus, 4-HI could be a potential clinical approach for treating post-brain haemorrhage and neurochemical changes caused by neurological damage. Furthermore, 4-HI may be linked to other standard therapeutic therapies utilized in ICH as a potential pharmacological intervention.

Treadmill exercise ameliorates chronic REM sleep deprivation-induced anxiety-like behavior and cognitive impairment in C57BL/6J mice

Various sleep disorders have deleterious effects on mental and cognitive performance. Exercise, as an alternative therapeutic strategy, exerts beneficial impacts on human health. In the present study, we aimed to evaluate the effects of 4 weeks treadmill exercise (4W-TE) on anxiety-like behavior and cognitive performance in mice exposed to 2 months REM sleep deprivation (2M-SD) (20 h per day). Behavioral performance of mice in elevated plus maze test (EPM), open field test (OFT), Y maze test (YM) and Morris water maze test (MWM) was recorded and analyzed 28 h after the last day of sleep deprivation. After behavioral tests, various neurotransmitters including norepinephrine (NE), dopamine (DA), serotonin (5-HT) and γ-aminobutyric acid (GABA) in mouse hippocampus were quantified using high performance liquid chromatography. The hippocampal levels of insulin-like growth factor-1 (IGF-1) and brain derived neurotrophic factor (BDNF) were further detected using ELISA. Behavioral data indicated that 2M-SD exposure induced anxiety-like behaviors and cognitive impairment, as evidenced by the decreased open-arm entries in EPM, reduced central area travels in OFT, declined spontaneous alteration in YM and prolonged escaping latency in MWM. In addition, 2M-SD exposure increased NE and DA, decreased 5-HT and GABA, and reduced IGF-1 and BDNF levels in mouse hippocampus. Interestingly, all these behavioral, neurochemical and neurobiological changes can be ameliorated by 4W-TE training. In summary, these findings confirm the beneficial impacts of exercise on health and provide further experimental evidence for future application of exercise as an alternative therapy against the mental and cognitive problems in patients with sleep disorders.

Neuroprotective potential of solanesol in a combined model of intracerebral and intraventricular hemorrhage in rats

Intracerebral hemorrhage (ICH) may be caused by trauma, aneurysm and arteriovenous malformation, as can any bleeding within the intracranial vault, including brain parenchyma and adjacent meningeal spaces (aneurism and atreovenous malformation). ICH is the cerebral stroke with the least treatable form. Over time, intraventricular hemorrhage (IVH) is associated with ICH, which contributes to hydrocephalus, and the major cause of most hemorrhagic death (Due to the cerebral hemorrhage and post hemorrhagic surgeries). Most patients suffer from memory impairment, grip strength, posture, and cognitive dysfunctions attributable to cerebral hemorrhage or post-brain hemorrhagic surgery. Nevertheless, a combined model of ICH based IVH is not present pre-clinically. Autologous blood (ALB) injection (20 μl/5 min) in the rat brain triggers hemorrhage, such as factors that further interfere with the normal functioning of neuroinflammatory cytokines, oxidative stress, and neurotransmitter dysfunction, such as CoQ10 insufficiency and dysregulation of mitochondrial ETC-complexes. For the prevention of post-brain hemorrhagic behavioral and neurochemical dysfunctions, there is no specific drug treatment available, only available therapy used to provide symptomatic relief. The current study reveals that long-term administration of Solanesol (SNL) 40 and 60 mg/kg alone and in combination with available drug therapy Donepezil (DNP) 3 mg/kg, Memantine (MEM) 20 mg/kg, Celecoxib (CLB) 20 mg/kg, Pregabalin (PGB) 30 mg/kg, may provide the neuroprotective effect by improving behavioral and neurochemical deficits, and gross pathological changes in ALB induced combined experimental model of ICH-IVH in post brain hemorrhagic conditions in rats. Thus, SNL can be a potential therapeutic approach to improve neuronal mitochondrial dysfunction associated with post brain hemorrhagic behavioral and neurochemical alterations.

Running exercise protects oligodendrocytes in the medial prefrontal cortex in chronic unpredictable stress rat model

Previous postmortem and animal studies have shown decreases in the prefrontal cortex (PFC) volume and the number of glial cells in the PFC of depression. Running exercise has been shown to alleviate depressive symptoms. However, the effects of running exercise on the medial prefrontal cortex (mPFC) volume and oligodendrocytes in the mPFC of depressed patients and animals have not been investigated. To address these issues, adult male rats were subjected to chronic unpredictable stress (CUS) for 5 weeks, followed by treadmill running for 6 weeks. Then, the mPFC volume and the mPFC oligodendrocytes were investigated using stereology, immunohistochemistry, immunofluorescence and western blotting. Using a CUS paradigm that allowed for the analysis of anhedonia, we found that running exercise alleviated the deficits in sucrose preference, as well as the decrease in the mPFC volume. Meanwhile, we found that running exercise significantly increased the number of CNPase⁺ oligodendrocytes and Olig2⁺ oligodendrocytes, reduced the ratio between Olig2⁺/NG2⁺ oligodendrocytes and Olig2⁺ oligodendrocytes and increased myelin basic protein (MBP), CNPase and Olig2 protein expression in the mPFC of the CUS rat model. However, running exercise did not change NG2⁺ oligodendrocyte number in the mPFC in these rats. These results indicated that running exercise promoted the differentiation of oligodendrocytes and myelin-forming ability in the mPFC in the context of depression. These findings suggest that the beneficial effects of running exercise on mPFC volume and oligodendrocytes in mPFC might be an important structural basis for the antidepressant effects of running exercise.

Effects of treadmill exercise on the anxiety-like behavior through modulation of GSK3β/β-catenin signaling in the maternal separation rat pup

Maternal separation causes depression and anxiety. Exercise ameliorates maternal separation-induced depression. In this study, we investigated the effect of treadmill exercise on anxiety-like behavior in relation with glycogen synthase kinase 3 beta (GSK3β)/β-catenin pathway using maternal separation rat pups. For this study, elevated plus maze test, immunohistochemistry for serotonin (5-hydroxytryptamine, 5-HT), tryptophan hydroxylase (TPH), and western blot for total GSK3β (t-GSK3β), phosphorylated GSK3β (p-GSK3β), total β-catenin (t-β-catenin), and phosphorylated β-catenin (p-β-catenin) were conducted. The rat pups in the exercise groups were scheduled to run on a treadmill for 30 min once a day for 10 days, starting on postnatal day 21. For the rat pups in the fluoxetine-treated group, fluoxetine was orally administrated once a day for 10 consecutive days, starting on postnatal day 21. Anxiety-like behavior was appeared in the rat pups by maternal separation. Maternal separation suppressed 5-HT and TPH expression in the dorsal raphe. Maternal separation suppressed phosphorylation of GSK3β and increased phosphorylation of β-catenin in the hippocampus. However, treadmill exercise and fluoxetine treatment alleviated anxiety and increased 5-HT and TPH expression in the dorsal raphe. Treadmill exercise and fluoxetine treatment also enhanced GSK3β phosphorylation and suppressed β-catenin phosphorylation in the hippocampus. In this study, alleviating effect of treadmill exercise on maternal separation-induced anxiety appeared through enhancing 5-HT expression and GSK3β phosphorylation, and then inhibiting β-catenin phosphorylation. These results showed that treadmill exercise relieves anxiety through GSK3β/β-catenin pathway. Treadmill exercise showed similar ameliorating effect on anxiety-like behavior as fluoxetine.

Treadmill Exercise Improves Motor Function by Suppressing Purkinje Cell Loss in Parkinson Disease Rats

PURPOSE

Rotenone is the most widely used neurotoxin for the making Parkinson disease (PD) animal model. The neurodegenerative disorder PD shows symptoms, such as slowness of movements, tremor at resting, rigidity, disturbance of gait, and instability of posture. We investigated whether treadmill running improves motor ability using rotenone-caused PD rats. The effect of treadmill running on PD was also assessed in relation with apoptosis of cerebellar Purkinje cells.

METHODS

Treadmill running was applied to the rats in the exercise groups for 30 minutes once a day for 4 weeks, starting 4 weeks after birth. We used rota-rod test for the determination of motor coordination and balance. In this experiment, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, immunohistochemistry for calbindin, glial fibrillary acidic protein (GFAP), Iba-1, and western blot analysis for Bax and Bcl-2 were performed.

RESULTS

Treadmill running enhanced motor balance and coordination by preventing the loss of Purkinje cells in the cerebellar vermis. Treadmill running suppressed PD-induced expression of GFAP-positive reactive astrocytes and Iba-1-positive microglia, showing that treadmill running suppressed reactive astrogliosis and microglia activation. Treadmill running suppressed TUNEL-positive cell number and Bax expression and enhanced Bcl-2 expression, demonstrating that treadmill running inhibited the progress of apoptosis in the cerebellum of rotenone-induced PD rats.

CONCLUSION

Treadmill running improved motor ability of the rotenone-induced PD rats by inhibiting apoptosis in the cerebellum. Apoptosis suppressing effect of treadmill running on rotenone-induced PD was achieved via suppression of reactive astrocyte and inhibition of microglial activation.

Dexmedetomidine Ameliorates Sleep Deprivation-Induced Depressive Behaviors in Mice

PURPOSE

Sleep deprivation induces depressive symptoms. Dexmedetomidine is a α2-adrenoreceptor agonist and this drug possesses sedative, anxiolytic, analgesic, and anesthetic-sparing effect. In this study, the action of dexmedetomidine on sleep deprivation-induced depressive behaviors was investigated using mice.

METHODS

For the inducing of sleep deprivation, the mice were placed inside a water cage containing 15 platforms and filled with water up to 1 cm below the platform surface for 7 days. One day after sleep deprivation, dexmedetomidine at the respective dosage (0.5, 1, and 2 μg/kg) was intraperitoneally treated into the mice, one time per a day during 6 days. Then, forced swimming test and tail suspension test were conducted. Immunohistochemistry for tyrosine hydroxylase (TH), 5-hydroxytryptamine (5-HT; serotonin), tryptophan hydroxylase (TPH) and western blot for D1 dopamine receptor were also performed.

RESULTS

Sleep deprivation increased the immobility latency in the forced swimming test and tail suspension test. The expressions of TPH, 5-HT, and D1 dopamine receptor were decreased, whereas, TH expression was increased by sleep deprivation. Dexmedetomidine decreased the immobility latency and increased the expressions of TPH, 5-HT, and D1 dopamine receptor, whereas, HT expression was decreased by dexmedetomidine treatment.

CONCLUSION

In our results, dexmedetomidine alleviated sleep deprivation-induced depressive behaviors by increasing 5-HT synthesis and by decreasing dopamine production with up-regulation of D1 dopamine receptor.

Changes in motor function, cognition, and emotion-related behavior after right hemispheric intracerebral hemorrhage in various brain regions of mouse

Intracerebral hemorrhage (ICH) is a detrimental type of stroke. Mouse models of ICH, induced by collagenase or blood infusion, commonly target striatum, but not other brain sites such as ventricular system, cortex, and hippocampus. Few studies have systemically investigated brain damage and neurobehavioral deficits that develop in animal models of ICH in these areas of the right hemisphere. Therefore, we evaluated the brain damage and neurobehavioral dysfunction associated with right hemispheric ICH in ventricle, cortex, hippocampus, and striatum. The ICH model was induced by autologous whole blood or collagenase VII-S (0.075 units in 0.5 µl saline) injection. At different time points after ICH induction, mice were assessed for brain tissue damage and neurobehavioral deficits. Sham control mice were used for comparison. We found that ICH location influenced features of brain damage, microglia/macrophage activation, and behavioral deficits. Furthermore, the 24-point neurologic deficit scoring system was most sensitive for evaluating locomotor abnormalities in all four models, especially on days 1, 3, and 7 post-ICH. The wire-hanging test was useful for evaluating locomotor abnormalities in models of striatal, intraventricular, and cortical ICH. The cylinder test identified locomotor abnormalities only in the striatal ICH model. The novel object recognition test was effective for evaluating recognition memory dysfunction in all models except for striatal ICH. The tail suspension test, forced swim test, and sucrose preference test were effective for evaluating emotional abnormality in all four models but did not correlate with severity of brain damage. These results will help to inform future preclinical studies of ICH outcomes.

Treadmill exercise ameliorates depressive symptoms through increasing serotonin expression in postpartum depression rats

Postpartum depression (PPD) is defined as the depressive symptoms that occur from the moment of delivery until 12 months after delivery. PPD symptoms are closely associated with reduced activity of the serotonergic system. Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in the pathogenesis of depression. Tryptophan hydroxylase (TPH) catalyzes the rate-limiting step of 5-HT biosynthesis in the serotonergic neurons. Exercise exerts anti-depressive effect on depression patients as well as on animal models of depression. In the present study, the effect of treadmill exercise on PPD was investigated using rats. For this study, open field test for activity and forced swimming test for depressive symptoms, and immunohistochemistry for 5-HT and TPH were conducted. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 2 weeks. Activity in the open field test was decreased in the postpartum rats, however, performing treadmill running increased activity in the postpartum rats. The climbing time was decreased and the immobility time was increased in the postpartum rats. Treadmill exercise increased climbing time and suppressed immobility time in the postpartum rats. 5-HT and TPH expressions in the dorsal raphe were suppressed in the postpartum rats, and treadmill exercise enhanced 5-HT and TPH expressions in the postpartum rats. Treadmill exercise ameliorated the PPD very effectively by enhancing serotonin level.

Dexmedetomidine Oral Mucosa Patch for Sedation Suppresses Apoptosis in Hippocampus of Normal Rats

Purpose

Dexmedetomidine, an α2-adrenergic agonist, provides sedative and analgesic effects without significant respiratory depression. Dexmedetomidine has been suggested to have an antiapoptotic effect in response to various brain insults. We developed an oral mucosa patch using dexmedetomidine for sedation. The effects of the dexmedetomidine oral mucosa patch on cell proliferation and apoptosis in the hippocampus were evaluated.

Methods

A hydrogel oral mucosa patch was adhered onto the oral cavity of physiologically normal rats, and was attached for 2 hours, 6 hours, 12 hours, or 24 hours. Plasma dexmedetomidine concentrations were determined by liquid chromatography– electrospray ionization–tandem mass spectrometry–multiple-ion reaction monitoring (LC-ESI-MS/MS-MRM). Cell proliferation in the hippocampus was detected by Ki-67 immunohistochemistry. Caspase-3 immunohistochemistry, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, and Western blotting for Bax and Bcl-2 were performed to detect hippocampal apoptosis. The levels of brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) in the hippocampus were also measured by Western blotting.

Results

Plasma dexmedetomidine concentration increased according to the attachment time of the dexmedetomidine oral mucosa patch. Hippocampal cell proliferation did not change due to the dexmedetomidine oral mucosa patch, and the dexmedetomidine oral mucosa patch exerted no significant effect on BDNF or TrkB expression. In contrast, the dexmedetomidine oral mucosa patch exerted an antiapoptotic effect depending on the attachment time of the dexmedetomidine oral mucosa patch.

Conclusions

A dexmedetomidine oral mucosa patch can be used as a convenient tool for sedation, and is of therapeutic value due to its antiapoptotic effects under normal conditions.

Treadmill exercise improves depression-like symptoms by enhancing serotonergic function through upregulation of 5-HT1A expression in the olfactory bulbectomized rats

The olfactory bulbectomy (OBX) is a well-known method inducing animal model of depression. Depression is associated with dysfunction of serotonin (5-hydroxytryptamine, 5-HT) system. In the present study, antidepressive effect of treadmill exercise was investigated using olfactory bulbectomized rats. After bilateral bulbectomy, the rats in the treadmill exercise groups were subjected to run on a treadmill for 30 min once a day during 28 days. Increased immobility time and decreased fast time in the forced swim test were observed in the olfactory bulbectomized rats. Sucrose preference in the sucrose preference test was decreased and activity in the open field test was also increased in the olfactory bulbectomized rats. Treadmill exercise decreased immobility time and activity and increased fast time and sucrose preference in the olfactory bulbectomized rats. Expressions of 5-HT and tryptophan hydroxylase (TPH) in the dorsal raphe of rats were suppressed by OBX and treadmill exercise increased the expressions of 5-HT and TPH in the olfactory bulbectomized rats. Serotonin receptor type 1A (5-HT1A) expression in the dorsal raphe was reduced by OBX and treadmill exercise increased 5-HT1A expression in the olfactory bulbectomized rats. In the present study, treadmill exercise ameliorated OBX-induced depressive symptoms. The antidepressive effect of treadmill exercise might be ascribed to the enhancement of serotonergic function through upregulation of 5-HT1A expression in the dorsal raphe.