Reduction of long-term potentiation at Schaffer collateral-CA1 synapses in the rat hippocampus at the acute stage of vestibular compensation

Vestibular compensation is a recovery process from vestibular symptoms over time after unilateral loss of peripheral vestibular end organs. The aim of the present study was to observe time-dependent changes in long-term potentiation (LTP) at Schaffer collateral-CA1 synapses in the CA1 area of the hippocampus during vestibular compensation. The input-output (I/O) relationships of fEPSP amplitudes and LTP induced by theta burst stimulation to Schaffer's collateral commissural fibers were evaluated from the CA1 area of hippocampal slices at 1 day, 1 week, and 1 month after unilateral labyrinthectomy (UL). The I/O relationships of fEPSPs in the CA1 area was significantly reduced within 1 week post-op and then showed a non-significant reduction at 1 month after UL. Compared with sham-operated animals, there was a significant reduction of LTP induction in the hippocampus at 1 day and 1 week after UL. However, LTP induction levels in the CA1 area of the hippocampus also returned to those of sham-operated animals 1 month following UL. These data suggest that unilateral injury of the peripheral vestibular end organs results in a transient deficit in synaptic plasticity in the CA1 hippocampal area at acute stages of vestibular compensation.

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.

Effect of Image Making Programs on Image Making Efficacy, Positive Thinking, Self-esteem, and Nursing Professionalism in Nursing Students / 간호행정학회지

PURPOSE: This study was conducted to test the effect of Image Making Programs on image making efficacy, positive thinking, self-esteem, and nursing professionalism in nursing students. METHODS: A non-equivalent control group pretest-posttest design was used. Participants were 124 nursing students at two universities, and were assigned to the treatment group (n=62) or the comparison group (n=62). The treatment was the Image Making Program, which was held twice over 2 days for 120 minutes per session. Data were collected from August to September 2012, and were analyzed using descriptive statistics, Kolmogorov-Smironov test, chi2-test, independent t-test, Mann-Whitney U test, one-tailed Mann-Whitney U test, independent one-tailed t-test with the SPSS/WIN 21.0 program. RESULTS: Nursing students in the treatment group showed statistically significantly higher levels of image making efficacy, positive thinking, and nursing professionalism than those in the comparison group. CONCLUSION: The results indicate that the Image Making Program is an effective intervention for increasing image making efficacy, positive thinking, and nursing professionalism in nursing students. However, further research and practices are needed in this area.

Erratum: Understanding of Structure and Function of Vestibular Cortex / 대한평형의학회지

No abstract available.

Understanding of Structure and Function of Vestibular Cortex / 대한평형의학회지

The vestibular end-organs generate very sophisticated gravity sensory information about head movement by sensing head acceleration in three-dimensional space. Vestibular information is crucial for higher brain functions such as cognition of spatial orientation, spatial memory, and perception of self-motion. The term "vestibular cortex" represents cortical area where vestibular information is processed, converged with other sensory inputs to maintain cortical functions. The vestibular cortex gives rise to commend signals that control the vestibulosomatic reflex through the modulation of vestibular nuclear activity in the brainstem. The vestibular cortex includes such different cortical regions as the premotor region of the frontal cortex, parietal areas, temporal areas, and a central core region called parietoinsular vestibular cortex. This paper summarizes systemically animal and clinical research data concerned with the vestibular cortex in order to understand anatomy and functions of the vestibular cortex and to provide a basic literature for further study.

Combined Effect of High Intensity Exercise and (-) Epigallocatechin-3-gallate of Green Tea Supplementation on Heme Oxygenase-1 in the Large Intestine of SD Rats / 대한스포츠의학회지

The purpose of this study was to investigate effects of combined treatment with high intensity exercise and (-) epigallocatechin-3 gallate (EGCG), a potent free radical scavenger on a transcriptional level of hemoxygenase-1 gene in the large intestine. Sprague-Dawley rats were randomly divided into control group (CON, n=7), high intensity exercise group (HIE, n=7), EGCG group (EGCG, n=7), and EGCG plus high intensity exercise group (HIE + EGCG, n=7). Animals were given an intraperitoneal injection of EGCG with 50 mg of dosage per kg for four weeks 30 minutes before exercise. In order to induce HIE animals were allowed to ran on a treadmill with 0 degree of slope at speed of 28 m/min for 30 minutes. The exercise was performed four times a week for four week. The results of this study were as following; The expression level of hemoxygenase-1 mRNA of the high intensity exercise group was 15.21 times higher than that of the control group. The EGCG plus high intensity exercise group showed 5.98 times increased expression level of hemoxygenase-1 mRNA than control group. These results suggest that treatment of EGCG decrease the expression level of HO-1 mRNA through the removal of oxygen radicals produced by a high intensity exercise.

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.

Water Extract of Samultang Reduces Apoptotic Cell Death by H2O2-Induced Oxidative Injury in SK-N-MC Cells

The purpose of this study was to evaluate the effects of the water extract of Samultang (SMT), a Chinese herb, on apoptotic cell death by H2O2-induced oxidative stress in SK-N-MC cells. A nuclear fragmentation was observed via fluorescence imaging 12 h after exposure to 30 micrometer H2O2 and DNA laddering was detected via agarose electrophoresis gel. In addition, increases in sub-G1 phase and cleavage of the PARP protein were observed. However, treatment with SMT for 2 h prior to H2O2 exposure significantly reduced apoptotic cell death induced by incubation with 30 micrometer H2O2 in SK-N-MC cells. Pre-incubation with water extract of SMT for 2 h prevented the H2O2-induced decrease in mitochondrial transmembrane potential. SMT also attenuated the increase in caspase-3 activity and the breakdown of PARP protein caused by H2O2-induced oxidative stress. These results suggest that the water extract of SMT provides inhibition of apoptotic cell death against oxidative injury in SK-N-MC cells.

Role of the Peripheral Vestibular System on Neuroplasticity Induced by Hypergravity Stimulation

BACKGROUND AND OBJECTIVES: Altered environmental gravity, including both hypo- and hypergravity, may result in space adaptation syndrome. To explore the characteristics of this adaptive plasticity, the expression of immediate early gene c-fos mRNA in the vestibular system following an exposure to hypergravity stimulus was determined in rats. MATERIALS AND METHOD: The animals were subjected to 2 G force (two-fold earth's gravity) stimulus for 3 hours, and were examined at post-stimulus hours 0, 2, 6, 12, and 24. Real time reverse transcription-polymerase chain reaction (RT-PCR) was adopted to analyze temporal changes in the expression of c-fos mRNA. RESULTS: The hypergravity stimulation produced the expression of c-fos mRNA in the vestibular ganglion, medial vestibular nucleus, inferior vestibular nucleus, hippocampus, vestibulocerebellum, and vestibular cortex. The peak expression occurred at hour 6 in the animals hypergravity-stimulated for 3 hours. Bilateral labyrinthectomy significantly attenuated the degree of up-regulation in c-fos mRNA expression. MK-801, an NMDA receptor antagonist, also significantly attenuated the degree of up-regulation in c-fos mRNA expression. CONCLUSION: These results indicate that the adaptive neuroplasticity in response to an altered gravity occurs in the vestibular-related organs in the central nervous system, in which peripheral vestibular receptors and NMDA receptors play an important role.