BACKGROUND: There is a little information about the effect of selective vestibular stimulation on the expression of activity-dependent metabolic markers in the vestibular nuclei. The purpose of this study was to evaluate effect of afferent excitation of the horizontal semicircular canal on expression of phosphorylated ERK1/2 (pERK1/2) and cFos proteins in the vestibular nuclei. METHODS: The horizontal semicircular canal of Sprague-Dawley rats was selectively stimulated by using the sinusoidal horizontal stimulator with 10-minute duration of stimulation. Conventional immunohistochemical method was used to visualize pERK1/2 or cFos immunoreactive neurons in the vestibular nuclei following rotation. RESULTS: Five minutes after stimulation of the horizontal semicircular canal there was a high expression of pERK1/2 protein in the medial vestibular nucleus among 4 major subnuclei of the central vestibular nuclear complex. On the contrary, immunoreactivity of cFos protein was observed in the medial and inferior vestibular nucleus 2 hours after horizontal sinusoidal rotation. The lateral vestibular nucleus was free from the expression of pERK1/2 and cFos proteins in response to excitation of the horizontal semicircular canal. However, in the vestibular nuclei of unilaterally labyrinthectomized rats expression of pERK and cFos proteins was markedly suppressed in ipsi-lesional side as well as contra-lesional side following stimulation of the horizontal semicircular canal. Furthermore no expression of pERK1/2 and cFos protein in the bilateral vestibular nuclei of bilaterally labyrinthectomized rats was noted after stimulation of the horizontal semicircular canal. CONCLUSIONS: Therefore these results of present study suggest that excitatory afferent signals from the peripheral vestibular receptors are essential for protein translation for pERK1/2 and cFos in response to stimulation of the semicircular canal.
Animals ; Neurons ; Protein Biosynthesis ; Rats ; Rats, Sprague-Dawley ; Semicircular Canals* ; Vestibular Nuclei* ; Vestibular Nucleus, Lateral

This study evaluated the expression of phosphorylated signal-regulated kinase1/2 (pERK1/2), which is one of the main factors regulating transcription of the cfos oncogene in neurons, in the vestibular nuclei of Sprague-Dawley rats following unilateral labyrinthectomy (UL). Surgical UL was performed to eliminate afferent signals from the peripheral vestibular receptors in the inner ear, under a surgical microscope, 2 hours after anesthesia. Significant numbers of pERK1/2 immunoreactive neurons were seen in the superior, medial, and inferior vestibular nuclei. There were more pERK1/2 immunoreactive cells in the vestibular nuclei contralateral than in the vestibular nuclei ipsilateral to the injured labyrinth, which resulted in significant asymmetric expression of pERK1/2 immunoreactive cells. Subsequently, the pERK1/2 immunoreactivity decreased rapidly, disappearing 90 min after labyrinthectomy. No pERK1/2 labeling was seen in the lateral vestibular nucleus. These results suggest that intracellular signal pathways for the activation of extracellular signal-regulated kinase in the vestibular nuclei are involved in lesion-neural plasticity in the vestibular system
Anesthesia ; Animals ; Ear, Inner ; Neurons ; Oncogenes ; Phosphotransferases ; Plastics ; Rats* ; Rats, Sprague-Dawley ; Signal Transduction ; Vestibular Nuclei* ; Vestibular Nucleus, Lateral

No abstract available.
Vestibular Nuclei*

BACKGROUND AND OBJECTIVES: The aim of this study was to examine the localizations of beta1- and beta2-adrenergic receptors (ARs) in rat vestibular nuclei by immunohistochemical staining procedure. MATERIALS AND METHODS: Twelve male Sprague-Dawley rats were used in this study. Primary antibodies for the beta1- and beta2-ARs were used. The sections were treated with a biotinylated goat anti-rabbit antibody. The sections were then incubated in avidin-biotin-peroxidase reagent and processed with immunoperoxidase using 3.3'-diaminobenzidine tetrahydrochloride. RESULTS: beta1-AR and beta2-AR immunopositive neurons were found to be distributed throughout the four major vestibular nuclei. Both receptors were primarily detected in neuronal somata and their proximal dendrites. beta1-AR and beta2-AR were moderately expressed in the superior vestibular nucleus, lateral vestibular nucleus, medial vestibular nucleus, and spinal vestibular nucleus. CONCLUSION: The present study demonstrates, for the first time, that beta1-AR and beta2-AR receptors are localized in rat vestibular nuclei. Furthermore, this study may provide additional speculation into the role of ARs during vestibular signal processing. Further studies are needed to clarify the roles played by beta1-ARs and beta2-ARs through physiologic and functional studies.
Animals ; Antibodies ; Dendrites ; Goats ; Humans ; Male ; Migraine Disorders ; Neurons ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic ; Vertigo ; Vestibular Nuclei ; Vestibular Nucleus, Lateral

No abstract available.
Chinchilla* ; Vestibular Nerve* ; Vestibular Nuclei*

No abstract available.
Infarction ; Neurons ; Vestibular Nuclei

No abstract available.
Gerbillinae* ; Vestibular Nuclei*

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.
Animals ; Arteries ; Rats ; Vertebrobasilar Insufficiency ; Vestibular Nuclei

Some individuals may demonstrate a secondary phase nystagmus (SPN) following the caloric irrigation. It has been stated that if a SPN begins prior to 140 seconds after the onset of caloric stimulation and if the magnitude of the slow phase velocity is greater than 6 degrees/sec, then a premature reversal caloric nystagmus (PRCN) is said to exit. Thus far, there have been no reports describing PRCN in Korea. We described a typical PRCN in a patient with medulloblastoma within the 4th ventricle. The patient had a gaze-evoked horizontal and upbeating nystagmus. However, there was no indication of spontaneous nystagmus. A monothermal caloric test was administered. The initial left beating primary phase nystagmus was subsided at 60 seconds after right cold water stimulation and at 110 seconds, a right beating SPN with 14 degrees/sec of slow phase velocity was appeared and was continuous for 240 seconds. Although the precise mechanism of PRCN is unknown, vestibular nuclei damage may be related.
Caloric Tests ; Humans ; Korea ; Medulloblastoma ; Nystagmus, Physiologic* ; Vestibular Nuclei ; Water

Periodic alternating nystagmus (PAN) is characterized by a periodical reversal in the direction of the nystagmus. Acquired PAN is caused by lesions of the inferior cerebellar vermis, causing disinhibition of the velocity storage mechanism, which is mediated by the vestibular nuclei. An eighty-year-old woman with abscess in midline cerebellum experienced dizziness and imbalance. We observed short period PAN with 7-8 seconds.
Abscess ; Cerebellum ; Dizziness ; Female ; Humans ; Nystagmus, Pathologic ; Vestibular Nuclei