Effect of electroacupuncture at tsusanli on regulation of stress response under etomidate anesthesia in rats / 临床麻醉学杂志

Objective To explore the effect of electroacupuncture (EA) at tusanli (ST36) on regulation of stress response under different doses of etomidate anesthesia in rats.Methods Sixty male Sprague-Dawley rats, weighing 280-310 g, were randomly divided into control group (group C), model group (group M), etomidate 60 mg/kg group (group E1), etomidate 30 mg/kg group (group E2), etomidate 60 mg/kg combined with EA group (group EA1) and etomidate 30 mg/kg combined with EA group (group EA2), n=10 in each group.All groups received inferior caudal trunk transection at the level between sacral spinal nerve 3 and 4 (S3, S4) to prepare acute stress response model except group C.Group M received no others treatment.The rats in group E1, group EA1, group E2 and group EA2 were intraperitoneally injected with 60, 60, 30 and 30 mg/kg etomidate, respectively.Group EA1 and group EA2 received EA ST36.The points were stimulated at a frequency of 2/100 Hz with 1 mA output and a dilatational wave, which lasted for 30 min.ACTH and Cor levels were measured by ELISA.The c-fos protein expression in hypothalamic tissue was examined by Western blot.Results Compared with group C, ACTH and Cor levels, and hypothalamic expression of c-fos protein in group M were significantly increased (P<0.05).Compared with group M, serum ACTH and Cor levels, and hypothalamic expression of c-fos protein in groups E1, E2, EA1 and EA2 were significantly decreased (P<0.05).Compared with group E1, serum ACTH and Cor levels, and hypothalamic expression of c-fos protein were significantly higher in groups E2 and EA1 (P<0.05).Compared with group E2, serum ACTH level and hypothalamic expression of c-fos protein were significantly lower in group EA2 (P<0.05).Conclusion EA at ST36 regulating stress response under etomidate anesthesia in rats is effective and two-way, and the mechanism may be due to the release of neurotransmitters induced c-fos protein in hypothalamus.

The effects of Bucinnazine Hydrochloride on the pain behavior and expression of caveolin-1 in anterior cingulate cortex of neuropathic pain mice / 中华行为医学与脑科学杂志

Objective To investigate the effects of Bucinnazine Hydrochloride on the pain behavior and the expression of caveolin-1 (Cav-1) in the anterior cingulate cortex of neuropathic pain mice.Methods 64 adult male Kunming mice (20-25g) were divided randomly into 4 groups with 16 in each group:Sham+BH(Bucinnazine Hydrochloride) group,Sham+NS (Normal Saline) group,CCI+ BH group and CCI+ NS group.The corresponding drugs were administered by intraperitoneal injectionfrom the forth day after CCI once a day for three days.Paw thermal withdrawal latency was measured by Hargreaves methods.Mechanicalwithdrawal threshold was assayed by electronic dolorimeter.c-Fos protein in anterior cingulate cortex was detected by immunohistochemistry staining and the expression of t-Cav-1,p-Cav-1was detected by Western blot.Results Bucinnazine Hydrochloride administered by intraperitoneal injection(0.1 mg/10 g,mice) alleviated thermal hyperalgesia and mechanical allodynia of CCI mice.Compared with the forth day (4.92±0.41) s of CCI+BH group,paw withdrawal latency on the fifth day(5.92±0.61) s was increased(P＜0.05),and on the sixth day(7.93±0.91) s and seventh day (9.12±0.69)s were increased more(P＜0.01,P＜0.01).The paw withdrawal mechanical threshold on the sixth and seventh day of CCI+BH group mice((2.54 ±0.41)g,(3.68±0.61)g) were increased significantly (P＜0.01,P＜0.01)compared with the forth day(1.55± 0.31)g.Immunohistochenistry results showed that the expression of c-Fos decreased after treated with Bucinnazine Hydrochloride in the anterior cingulate cortex of CCI mice(P＜0.001).Western Blotting showed that the expression of t-Cav-1 (1.97±0.31) and p-Cav-1 (0.11 ±0.09) in the anterior cingulate cortex of CCI +BH group mice decreased compared with that of in CCI+NS group mice(t-Cav-1:2.87±0.15,p-Cav-1:0.48± 0.09) (P＜0.01,P＜0.01).Conclusion Bucinnazine Hydrochloride can alleviate both thermal hyperalgesia and mechanical allodynia of neuropathic pain of mice,and reduce the expression of c-Fos,t-Cav-1,p-Cav-1 in the anterior cingulate cortex of neuropathic pain mice.

Pathways of Neurogenic and Humoral Control in the Vestibulosympathetic Reflex of Conscious Rats / 대한평형의학회지

OBJECTIVE: The vestibular system contributes control of blood pressure during postural changes through the vestibulosympathetic reflex. In the vestibulosympathetic reflex, afferent signals from the peripheral vestibular receptors are transmitted to the vestibular nuclei, rostral ventrolateral medullary nuclei, and then to the intermediolateral cell column of the thoracolumbar spinal cord. Physiological characteristics of the vestibulosympathetic reflex in terms of neurogenic and humoral control of blood pressure were investigated in this study. METHODS: Conscious rats with sinoaortic denervation were used for removal of baroreceptors in reflex control of blood pressure, and hypotension was induced by intravenous infusion of sodium nitroprusside (SNP). Expression of c-Fos protein was measured in the medial vestibular nuclei (MVN), rostral vestrolateral medullary nuclei(RVLM), and intermediolateral cell column (IMC) in T4-7, and levels of blood epinephrine were measured following SNP-induced hypotension. RESULTS: SNP-induced hypotension significantly increased expression of c-Fos protein in the MVN, RVLM, and IMC, also significantly increased level of blood epinephrine compared to normotensive control animals. CONCLUSION: These results suggest that the vestibulosympathetic reflex regulates blood pressure through neurogenic control including MVN, RVLM, and IMC, also through humoral control including epinephrine secretion by the adrenal medulla following SNP-induced hypotension. The physiological characteristics of the reflex may contribute to basic treatment of impairment of blood pressure control during postural changes.

Role of the Cerebral Cortex on Vestibular Compensation Following Unilateral Labyrinthectomy in Rats / 대한평형의학회지

OBJECTIVE: The cerebral cortex can modulate vestibular functions through direct control of neuronal activities in the vestibular nuclei. The purpose of this study was to investigate the effect of unilateral cortical lesion or cortical stimulation on static vestibular symptoms and vestibular nuclear activities at the acute stage of vestibular compensation following unilateral labyrinthectomy (UL) in rats. METHODS: The photothrombic ischemic injury using rose bengal was induced in the primary motor cortex or primary sensory cortex, and electrical stimulation was applied to the primary motor cortex, primary sensory cortex, or sencondary sensory cortex, respectively, in unilateral labyrinthectomized rats. Static vestibular symptoms including ocular movement and postural deficits, and expression of c-Fos protein in the medial vestibular nucleus (MVN) were measured. RESULTS: Lesion of the motor cortex produced a marked postural deficit with paralytic weakness in the hindlimb contralateral to UL. Number of spontaneous nystagmus in animals receiving cortical lesion was significantly increased 2, 6, and 12 hours after UL compared with animals being UL only. Lesion of the primary motor cortex or stimulation of the S2 sensory cortex decreased expression of c-Fos protein in MVN following UL compared with UL only group. Electrical stimulation of S2 sensory areas caused significant reduction of static vestibular symptoms and decreased expression of c-Fos protein in MVN 24 hours following UL. CONCLUSION: The present results suggest that cerebral cortex involves in recovery of static vestibular symptoms during vestibular compensation following UL.

Functional Connections of the Vestibulo-spino-adrenal Axis in the Control of Blood Pressure Via the Vestibulosympathetic Reflex in Conscious Rats

Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements. In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation. Expression of c-Fos protein in the intermediolateral cell column of the middle thoracic spinal regions and blood epinephrine levels were investigated, following microinjection of glutamate receptor agonists or antagonists into the medial vestibular nucleus (MVN) and/or sodium nitroprusside (SNP)-induced hypotension. Both microinjection of glutamate receptor agonists (NMDA and AMPA) into the MVN or rostral ventrolateral medullary nucleus (RVLM) and SNP-induced hypotension led to increased number of c-Fos positive neurons in the intermediolateral cell column of the middle thoracic spinal regions and increased blood epinephrine levels. Pretreatment with microinjection of glutamate receptor antagonists (MK-801 and CNQX) into the MVN or RVLM prevented the increased number of c-Fos positive neurons resulting from SNP-induced hypotension, and reversed the increased blood epinephrine levels. These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.

Effect of Glutamate on the Vestibulo-Solitary Projection after Sodium Nitroprusside-Induced Hypotension in Conscious Rats

Orthostatic hypotension is most common in elderly people, and its prevalence increases with age. Attenuation of the vestibulo-sympathetic reflex (VSR) is commonly associated with orthostatic hypotension. In this study, we investigated the role of glutamate on the vestibulo-solitary projection of the VSR pathway to clarify the pathophysiology of orthostatic hypotension. Blood pressure and expression of both pERK and c-Fos protein were evaluated in the nucleus tractus solitarius (NTS) after microinjection of glutamate into the medial vestibular nucleus (MVN) in conscious rats with sodium nitroprusside (SNP)-induced hypotension that received baroreceptor unloading via sinoaortic denervation (SAD). SNP-induced hypotension increased the expression of both pERK and c-Fos protein in the NTS, which was abolished by pretreatment with glutamate receptor antagonists (MK801 or CNQX) in the MVN. Microinjection of glutamate receptor agonists (NMDA or AMPA) into the MVN increased the expression of both pERK and c-Fos protein in the NTS without causing changes in blood pressure. These results indicate that both NMDA and AMPA receptors play a significant role in the vestibulo-solitary projection of the VSR pathway for maintaining blood pressure, and that glutamatergic transmission in this projection might play a key role in the pathophysiology of orthostatic hypotension.

Additive Role of the Vestibular End Organ and Baroreceptors on the Regulation of Blood Pressure in Rats

Contribution of the vestibular end organ to regulation of arterial pressure was quantitatively compared with the role of baroreceptors in terms of baroreflex sensitivity and c-Fos protein expression in the rostral ventrolateral medulla (RVLM). Baroreflex sensitivity and c-Fos protein expression in the RVLM were measured in conscious rats that had undergone bilateral labyrinthectomy (BL) and/or baroreceptor unloading. BL attenuated baroreflex sensitivity during intravenous infusion of sodium nitroprusside (SNP), but did not significantly affect the sensitivity following infusion of phenylephrine (PE). Baroreflex sensitivity became positive following sinoaortic denervation (SAD) during infusion of PE and attenuated sensitivity during infusion of SNP. Baroreflex sensitivity also became positive following double ablation (BL+SAD) during infusion of PE, and attenuated sensitivity during infusion of SNP. c-Fos protein expression increased significantly in the RVLM in the sham group after SNP administration. However, the BL, SAD, and SAD+BL groups showed significant decreases in c-Fos protein expression compared with that in the sham group. The SAD group showed more reduced c-Fos protein expression than that in the BL group, and the SAD+BL group showed less expression than that in the SAD group. These results suggest that the vestibular system cooperates with baroreceptors to maintain arterial pressure during hypotension but that baroreceptors regulate arterial pressure during both hypotension and hypertension. Additionally, afferent signals for maintaining blood pressure from the vestibular end organs and the baroreceptors may be integrated in the RVLM.

Role of the Peripheral Vestibular End Organ in the Expression of c-Fos Protein in the Medial Vestibular Nucleus Following Occlusion of the Anterior Inferior Cerebellar Artery / 대한평형의학회지

BACKGROUND AND OBJECTIVES: The present study investigated the role of the peripheral vestibular end organ in vestibular symptoms and temporal changes in expression of c-Fos protein in the vestibular nuclei following anterior inferior cerebellar artery (AICA) occlusion using rats with unilateral or bilateral labyrinthectomy. MATERIALS AND METHODS: Expression of c-Fos protein in the vestibular nuclei was measured 2, 12, 24, and 48 hours after AICA occlusion. RESULTS: Unilateral AICA occlusion significantly induced expression of c-Fos protein bilaterally in the medial, inferior, superior, and lateral vestibular nuclei. Following AICA occlusion, the medial vestibular nucleus (MVN) showed the highest expression of c-Fos protein among the 4 vestibular nuclei. The expression of c-Fos protein was asymmetric between the bilateral MVN, showing higher expression in the MVN contralateral to the side of AICA occlusion compared to the ipsilateral MVN. The degree of asymmetry in c-Fos protein expression between the bilateral MVN peaked 12 hours after AICA occlusion. The expression of c-Fos protein gradually decreased 24 hours after AICA occlusion and returned to control levels 48 hours after AICA occlusion. Unilateral labyrinthectomy significantly decreased expression of c-Fos protein in the MVN ipsilateral to the side of labyrinthectomy following AICA occlusion. Moreover, bilateral labyrinthectomy significantly decreased expression of c-Fos protein in the bilateral MVN flowing AICA occlusion. CONCLUSION: These results suggest that afferent signals from the peripheral vestibular end organ are crucial to the expression of c-Fos protein in the MVN following AICA occlusion and that expression of c-Fos protein is sustained for 24 hours after AICA occlusion.

Changes in the Gastrointestinal Motility following Unilateral Labyrinthectomy / 대한평형의학회지

BACKGROUND AND OBJECTIVES The temporal changes and the role of glutamate receptors in the recovery of vestibulogastrointestinal symptoms following unilateral labyrinthectomy (UL) were investigated in this study. Vestibulogastrointestinal symptoms were evaluated in terms of gastric emptying and intestinal transit. MATERIALS AND METHODS Expression of the c-Fos protein was observed in the solitary tract nucleus (STN) and rostral ventrolateral medullary nucleus (RVLM). These were measured at 0.5, 2, 6 and 24 h following UL in rats. RESULTS Gastric emptying and intestinal transit were significantly decreased for 6 h post UL and recovered to control levels within 24 h. Pretreatment of UL animals with MK-801 significantly increased the gastric emptying and intestinal transit. Bilateral labyrinthectomy significantly decreased the gastric emptying and intestinal transit compared to the intact labyrinthine animals but significantly increased when compared to UL animals. The expression of c-Fos protein was significantly increased in STN and RVLM compared to the control animals for 6 h post UL and recovered to control levels within 24 h. The expression was significantly decreased in animals that were pretreated with MK-801. CONCLUSION These results suggest that UL decreases the gastrointestinal motility, which recovers to control levels within 24 h post UL. Glutamate plays an important role in the recovery of vestibulogastrointestinal symptoms following UL.

c-fos Expression in Bladder-Specific Spinal Neurons after Spinal Cord Injury Using Pseudorabies Virus

PURPOSE: c-fos expression in spinal neurons that are activated by lower urinary tract stimulation are not organ specific. In this experiment, we demonstrated changes of c-fos expression in bladder-specific preganglionic neurons (PGNs) and interneurons using pseudorabies virus (PRV). MATERIALS AND METHODS: Forty Sprague-Dawley rats were used. We identified the neuronal pathway associated with the bladder by injecting PRV into the detrusor. An immunohistochemical method was used to stain Fos-protein encoded by the c-fos gene. Immunofluorescent staining for PRV was performed to evaluate changes in bladder-specific spinal neurons. RESULTS: Immunofluorescent staining with choline acetyltransferase (ChAT) revealed that the sacral parasympathetic nucleus (SPN) regions contained 9.8 PGNs/ section. In rats with chronic spinal cord injury by intravesical saline instillation, 82.4+/-10.3% of PGNs in SPN exhibited Fos-immunoreactive (IR). Two and a half days after PRV infection, PRV-IR PGNs were observed at 5.4 PGNs/ section, and 2.7+/-1.6% of them exhibited Fos-IR. Unlike ChAT-IR PGNs, PRV-IR PGNs are bladder-specific neurons and PRV-IR and Fos-IR cells found in the back of PRV-IR PGNs are bladder- specific interneurons. Three days after PRV infection, we observed many PRV-IR and Fos-IR cells in the dorsal commissure. These neurons are interneurons distributed in the bladder. CONCLUSION: We confirmed that in chronic spinal cord injury, the patterns of c-fos expression in bladder-specific spinal neurons were similar to those in voiding-reflex related spinal neurons, which had already been demonstrated earlier. We believe that our methodology can be applied to study interactions between voiding and other organs as well, such as the urethra and prostate.

Effect of Acupuncture Combined with Herb Decoction on Nerve Cell of Focal Brain Ischemia Rats / 中国中医药信息杂志

Objective To study the mechanism of acupuncture combined with herb decoction for brain occlusion. Methods one-side middle cerebral artery occlusion (McAo) rat by ehermoregulation was used as focal cerebral ischemia experimental animal. All animals were divided into four groups as model group, acupuncture group, herb decoction group, acupuncture combined with herb decoction group. And the dynamic changes of c-fos protein in ischemia region of brain tissue after treatment were observed. Results All of acupuncture group, herb decoction group and combining group could enhance the expression of c-fos protein in all stages of ischemia, and combining group was enhanced significantly. Conclusion Compared with herb decoction or acupuncture, the method of acupuncture combined with herb decoction could improved the stress ability of nerve cells of acute brain ischemia by enhance the content of c-fos protein significantly.

Expression of c-fos Protein in Hippocampus of Newborn Rats with Hypoxic-Ischemic Brain Damage and Its Significance / 实用儿科临床杂志

Objective To explore the relationship of c-fos protein and cell apoptosis by observing the expression of c-fos protein in hippocampus of newborn rat with hypoxic-ischemic brain damage(HIBD).Methods Forty-eight 7-day SD neonatal rats were randomly divided into control group(n=6) and experiment group(n=42).The models of HIBD were established in neonatal rats by inhaling the mixed gases of 920 mL/L N2 and 80 mL/L O2,and the animals were sacrificed by dislocation their heads at different time points(0.5,1,3,6,12,24,48,72 h),then the hippocampus were dissected by morphological analysis.Results The apoptotic cells appeared at the time point of 3 h,and reached the peak at 48 h,then decreased.The positive cell of c-fos protein increased from the time point of 30 min and reached the peak at 2 h and then decreased gradually,and there was a contrary tendency between the expression of c-fos protein and the number of damaged brain cells by HIBD(r=-0.57 P

The Role of the Vestibular System in Modulating Blood Pressure of Sinoaortic Denervated Rats

BACKGROUND AND OBJECTIVES: The vestibuloautonomic reflex controls respiration and blood pressure during locomotion. The purpose of this study was to investigate the role of the peripheral vestibular receptor in the control of blood pressure in sinoaortic denervated (SAD) rats. MATERIALS AND METHODS: The baroreceptor reflex was removed by SAD in labyrinthectomized rats. The expression of c-Fos protein in the vestibular nuclear complex, and other nuclei related to control of blood pressure, was measured following the induction of acute hypotension using sodium nitroprusside (SNP). RESULTS: The SNP induced acute hypotension, in intact labyrinthine rats, increased the expression of c-Fos protein in the supraoptic nucleus, paraventricular nucleus, rostral ventrolateral medulla, solitary nucleus, and vestibular nuclear complex. The expression of c-Fos protein, following the SNP induced acute hypotension in the SAD rats, increased the expression of c-Fos protein in the paraventricular nucleus, rostral ventrolateral medulla, and medial and inferior vestibular nuclei. The acute hypotension induced by SNP in a unilateral labyrinthectomy, with SAD, increased the expression of c-Fos protein in the contralesional vestibular nuclear complex, but decreased its expression in the ipsilesional vestibular nuclear complex. The acute hypotension induced by SNP in a bilateral labyrinthectomy, with SAD, showed only slight expression of c-Fos protein in the bilateral vestibular nuclear complex. CONCLUSION: These results suggest that the acute hypotension induced by SNP activates the vestibular nuclear neurons by decreasing the blood flow in the peripheral vestibular receptors, and that these in turn modulate blood pressure through activation of the catecholaminergic nervous system and neuroendocrine reflex.

C-fos Expression in Brain Stem of Rats after Salicylic Acid Treatment / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Subjective tinnitus, a distracting internal noise, is experienced by humans. Tinnitus is evoked by salicylic acid treatment in rats as confirmed by Jastreboff in 1994 in an animal behavior model of tinnitus with salicylic acid. The objective of this study is to evaluate c-fos expression in the brain stem of rats after salicylic acid treatment. MATERIALS AND METHOD: After salicylic acid (450 mg/kg) and saline treatment (450 mg/kg), c-fos immunohistochemical staining expression in the auditory and nonauditory brain stem nuclei were observed. RESULTS: Many immunoreactive cells were observed in the Locus Ceruleus of the salicylic acid treated animals, but not in the saline treated animals. No immunoreactive cells were found in the auditory brain stem nuclei. CONCLUSION: The Locus Ceruleus is the nucleus of the brain stem and produce norepinephrine which results in arousal of the neuronal activity for stress. These results suggest that salicylic acid may evoke tinnitus through a combined effect on the auditory and nonauditory brain nuclei. It seems possible that the interaction of these effects at particular locations of the brain causes tinnitus.

Auditory Auras in Complex Partial Epilepsy: Correlation of EEG and MRI Findings / 대한간질학회지

BACKGROUND: Auditory auras are rare but may have localizing value in patients presenting with epilepsy. We conducted the study to correlate the clinical characteristics, EEG and MRI findings in patients with auditory auras. METHODS: We identified 44 epileptic patients (23 male, 21 female) with auditory auras from Yonsei epilepsy registry between 1989 and 2000. All had routine EEG and MRI. These patients were subjected for the classification of lobar epilepsies based on the clinical-EEG-MRI correlations, which aimed at demonstrating 1) the association of auditory auras with temporal lobe epilepsy and 2) the localizing value of auditory auras to the neocortical temporal lobe epilepsy. RESULTS: Auditory auras were elementary in twenty-three, complex in eighteen, and both in three. Twenty patients described auditory aura only, and 24 patients described other associated auras including cephalic sensation, emotional, experiential, autonomic, epigastric, visual, vestibular, and somatosensory phenomena. The classification based on the Clinic-EEG-MRI correlations revealed that 33 of 44 patients (75%) were classified as temporal lobe epilepsy, however, it did not suggest any strong correlations with neocortical temporal lobe epilepsy. CONCLUSION: Auditory aura was strongly related with the temporal lobe epilepsy but it did not provide any further localizing value of seizure origin in patients with TLE.

Electrical stimulation can facilitate vestibular compensation following unilateral labyrinthectomy in rats

To investigate the effects of electrical stimulation on vestibular compensation, which is the recovery of vestibular symptoms following unilateral labyrinthectomy (UL), intermittent electrical stimulation was applied to the injured vestibular portion in Sprague-Dawley rats. Vestibuloocular and vestibulospinal reflexes, electrical activity and expression of c-Fos protein in medial vestibular nuclei (MVN) were measured with time following UL. Spontaneous nystagmus occurred with frequency of 2.9+/-0.2 beats/sec at 2 hours after UL and disappeared after 72 hours. Electrical stimulation decreased the frequency of nystagmus significantly till 24 hours after UL. Roll head deviation was 107+/-9.7degree at 2 hours after UL and the deviation was maintained till 72 hours, but electrical stimulation decreased the deviation significantly 6 hours after UL. Resting activity of type I neurons in ipsilateral MVN to the injured vestibular side decreased significantly compared with control at 6 and 24 hours after UL, but the activity of type I neurons was recovered to control level by electrical stimulation at 24 hours after UL. Gain of type I neurons induced by sinusoidal rotation of 0.1 Hz decreased significantly till 24 hours after UL, but electrical stimulation restored the activity at 24 hours. The gain of type II neurons decreased significantly at 6 hours after UL, but electrical stimulation restored the activity. Expression of c-Fos protein was asymmetric between bilateral MVN till 24 hours after UL, but the asymmetry disappeared by electrical stimulation 6 hours after UL. These results suggest that electrical stimulation to the injured vestibular portion facilitates vestibular compensation following UL by restoration of symmetry of neuronal activity between bilateral vestibular nuclei resulting from increased activity in ipsilateral vestibular nuclei to the injured side.

The Role of the Cerebellar Uvulonodulus on the Early Stage of Vestibular Compensation in Rats / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Many expeerimental evidences have beensupported that the vestibulocerebellum involved in recovery of vestibular compensation. The purpose of this study was to investigate effect of unilateral ablation of uvula and nodular lobes on early stage of vestibular compensation. MATERIALS AND METHODS: Adult Sprague-Dawley rats weighing 250~300 g were used and divided into control (CON) group receiving sham operation, unilateral labyrinthectomy (ULX) group, ULX plus left uvulonodulectomy (ULX+Lt-UNLX) group, and ULX plus right uvulonodulectomy (ULX+Rt-UNLX) group. UNLX was performed 1 hour following ULX. Spontaneous nystagmus (SN) and roll head tilt (RHT) were recorded for 3 days following ULX. Temporal change of c-Fos protein expression in the medial vestibular nuclei (MVN) was measured for 2 days following ULX. RESULTS: There were observed SN with contralateral direction to injured labyrinth and RHT toward ipsilateral side with flexion of ipsilateral limb and extenstion of contralateral one just after ULX. There was significant increase in SN frequency of ULX+Rt-UNLX group compared with that of ULX group. In addition, ULX+Rt-UNLX group resulted in severe postural asymmetry. ULX elicited prominent expression of c-Fos protein in contralateral MVN 2 hours but in ipsilateral one 6, 24 hours after ULX, respectively. In contrast, number of c-Fos positive neurons was higher in contralateral MVN. 24 hours after ULX higher expression of c-Fos protein in contralteral MVN was still remained in ULX+Rt-UNLX group but that in ipsilateral MVN was observed in ULX+Lt-UNLX group. CONCLUSION: These results suggest that UNLX have a different effect on the early stage of vestibular compensatory process and the uvulonodulus serves the restoration of balance between intervestibular nuclear activities after ULX by inhibition of vestibular nuclear complex through nhibitory Purkinje system.

The Relationship between Sleep c-fos Protein in Hypothalamus in Chronic Uremic Rats / 대한신장학회잡지

The activation of c-fos protein (FOS) in ventrol- ateral preoptic neuron (VLPO) induces sleep (Science 271; 216-219, 1996). Although sleep disturbance are very common in patients with chronic renal failure, its mechahanism of sleep disturbance is not clear. The purpose of this study was to evaluate sleep dissturbance and expression of FOS in VLPO of chronic uremic rats. Chronic uremic rats were induced by 5/6 nephrectomized rnodel. After 4 weeks, blood urea nitrogen and serum creatinine in uremic rats (n=14 were higher than in control (n=17) (blood urea nitrogen; 73.6+/-24.8 mg/dl vs. 23.3+/-2.9 mg/dl, P<0.001 serum creatinine', 1.49+/-0.42 mg/dl vs. 0.66+/-0.12 mg/dl, P<0.001). General activity was counted with infrared during day time (08:00-20:00) and night time (20:00-08:00). Rats were killed at 10:00 or 16:00 during day time (uremic rats 7, control 9) and at 22:00 during night time (uremic rats 7, control 7). The expression of FOS in VLPO was examined with immunohistochernical method. The number of day tirne general activity in uremic rats was significantly higher than in control (458+/-185 vs. 222+/-41, P<0.001), and the number of night time general activity in uremic rats was lower than in control (949+/- 430 vs. 1618+/-261, P<0.001). During day time, the number of FOS immunoreactive cell in uremic rats was lower than in control (18.4+/-5.3 vs. 42.8+/-6.3, P<0.001), but there was no difference between 2 groups at night time (10.8+/-8.4 vs 12.5+/-5.1, P=0.62). There was strong negative correlation between the number of activity and the number of FOS immunoreactive cell in control (r= -0.93, P<0.001), but there was no correlation in uremic rats. This study shows that sleep disturbance in chronic uremic rats might be related to decrease of expression of FOS in VLPO.

Relationship between Recovery of Vestibuloocular Reflex and c-Fos Protein Expression in Medial Vestibular Nuclei Following Unilateral Labyrinthectomy in Rats / 대한이비인후과학회지

Relationships between recovery of vestibuloocular reflex and expression of c-fos immunoreactive cells in the medial vestibular nuclei following unilateral labyrinthectomy(ULX) were investigated in rats. Frequency of spontaneous nystagmus, velocity of eye movement induced by sinusoidal rotation of the whole body at frequencies of 0.1, 0.2, 0.5Hz, and the number of c-fos immunoreactive cells in the medial vestibular nuclei were measured for 72 hours after ULX. Frequency of spontaneous nystagmus was 3.9+/-0.5 beats/sec(M+/-SD) immediately after ULX and disappeared completely within 48 hours. On sinusoidal rotation, eye movement induced by rotation toward the lesioned side recovered normal pattern within 24 hours at 0.1Hz rotation, and 12 hours at 0.2, 0.5Hz. Directional preponderance which represents the symmetry of bilateral vestibular functions decreased to less than 20% at 72 hours, but did not recover normal limit. The number of c-fos immunoreactive cells in the bilateral medial vestibular nuclei was severe asymmetry till 24 hours of ULX. However, the symmetry was recovered after 48 hours. These results indicate that the recovery of vestibuloocular reflex correlates with the expression of c-Fos immunoreactive cells of the medial vestibular nuclei in the early stage of vestibular compensation following ULX. Therefore, the vestibular nuclei may play a key role in vestibular compensation.

C-fos Protein Expression of the Rats on the Brain after 12 Hours Sleep Deprivation of Day and Night / 中国临床心理学杂志

Objective: To investigate the brain mechanisms of sleep deprivation. Methods: Sprague-Dawley rats were sleep deprived by housing them on the small platforms over water. Controls were housed in the normal cage(CC) or on the large platforms over water(TC). The effects of SD on the expression of c-fos protein by immunocytochemistry were investigated. The duration of SD was about 12 hours. They were divided into two groups: early SD group (from 7:00 am) and the late SD group (from 19:00 pm). Results: SD resulted in different expression of c-fos protein at different fields of the brain. The main fields of brain stem were all connected with paradoxical sleep. Compared with the late SD, the early SD group showed higher fos protein expression on suprachiasmatic.Conclusion: The disruption of regular circadian rhythm may affect c-fos protein expression.