Injections of calmidazolium chloride into the ipsilateral medial vestibular nucleus or fourth ventricle reduce spontaneous ocular nystagmus following unilateral labyrinthectomy in guinea pigs

1993 ◽  
Vol 93 (2) ◽  
Author(s):  
AndrewJ. Sansom ◽  
CynthiaL. Darlington ◽  
PaulF. Smith ◽  
DarrinP.D. Gilchrist ◽  
CiandraJ. Keenan ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Fourth Ventricle ◽  
Vestibular Nucleus ◽  
Medial Vestibular Nucleus ◽  
Ocular Nystagmus ◽  
Unilateral Labyrinthectomy

Unilateral labyrinthectomy induced changes on GDNF receptor complex proteins in the rat medial vestibular nuclei

2007 ◽  
Vol 16 (4-5) ◽  
pp. 171-177
Author(s):  
Adrian Lozada ◽  
Kaj Karlstedt ◽  
Pertti Panula ◽  
Antti A. Aarnisalo
Keyword(s):  
Mrna Expression ◽  
Vestibular Nucleus ◽  
Medial Vestibular Nucleus ◽  
Receptor Complex ◽  
Trophic Effect ◽  
Expression Levels ◽  
Protein Levels ◽  
Unilateral Labyrinthectomy ◽  
Ganglion Neurons ◽  
Mrna Expression Levels

In the auditory periphery, GDNF has been shown to have a trophic effect to spiral ganglion neurons, both during development and in adult animals. We have studied the effect of unilateral labyrinthectomy (UL) on protein levels and expression of GDNF multicomponent receptor complex: the ret tyrosine kinase and coreceptor GFRα-1 in the medial vestibular nucleus of the adult rat. GFRα-1 protein levels display an increasing trend in ipsilateral medial vestibular nucleus culminating at 48 h post UL. On the other hand, GFRα-1 mRNA expression levels in ipsi- and contralateral medial vestibular nucleus show a steadily decreasing trend that is significant at 1 week post-lesion. Protein levels for c-Ret isoforms also show an initial bilateral decreasing trend that ceases at 48 h in ipsilateral medial vestibular nucleus but persists on the contralateral side. c-Ret mRNA expression levels show a significant decrease at 4 h post UL followed by another significant decrease 1 week post UL. Our data would suggest that neurotrophins belonging to the GDNF family are involved in this model of post-lesional CNS plasticity.

scholarly journals The Changes in mGluR2 and mGluR7 Expression in Rat Medial Vestibular Nucleus and Flocculus Following Unilateral Labyrinthectomy

2013 ◽  
Vol 14 (11) ◽  
pp. 22857-22875 ◽  
Author(s):  
Wen Zhou ◽  
Liu-Qing Zhou ◽  
Su-Lin Zhang ◽  
Bo Liu ◽  
Yang-Ming Leng ◽  
...  
Keyword(s):  
Vestibular Nucleus ◽  
Medial Vestibular Nucleus ◽  
Unilateral Labyrinthectomy

Long-Term Plasticity of Ipsilesional Medial Vestibular Nucleus Neurons After Unilateral Labyrinthectomy

2003 ◽  
Vol 90 (1) ◽  
pp. 184-203 ◽  
Author(s):  
Mathieu Beraneck ◽  
Mohammed Hachemaoui ◽  
Erwin Idoux ◽  
Laurence Ris ◽  
Atsuhiko Uno ◽  
...  
Keyword(s):  
Vestibular Nucleus ◽  
Type A ◽  
Vestibular Compensation ◽  
Membrane Properties ◽  
Medial Vestibular Nucleus ◽  
Type B ◽  
Dynamic Membrane ◽  
Vestibular Neurons ◽  
Unilateral Labyrinthectomy

Unilateral labyrinthectomy results in oculomotor and postural disturbances that regress in a few days during vestibular compensation. The long-term (after 1 mo) consequences of unilateral labyrinthectomy were investigated by characterizing the static and dynamic membrane properties of the ipsilesional vestibular neurons recorded intracellularly in guinea pig brain stem slices. We compared the responses of type A and type B medial vestibular nucleus neurons identified in vitro to current steps and ramps and to sinusoidal currents of various frequencies. All ipsilesional vestibular neurons were depolarized by 6–10 mV at rest compared with the cells recorded from control slices. Both their average membrane potential and firing threshold were more depolarized, which suggests that changes in active conductances compensated for the loss of excitatory afferents. The afterhyperpolarization and discharge regularity of type B but not type A neurons were increased. All ipsilesional vestibular cells became more sensitive to current injections over a large range of frequencies (0.2–30 Hz), but this increase in sensitivity was greater for type B than for type A neurons. This was associated with an increase of the peak frequency of linear response restricted to type B neurons, from 4–6 to 12–14 Hz. Altogether, we show that long-term vestibular compensation involves major changes in the membrane properties of vestibular neurons on the deafferented side. Many of the static and dynamic membrane properties of type B neurons became more similar to those of type A neurons than in control slices, leading to an increase in the overall homogeneity of medial vestibular nucleus neurons.

Long-term Potentiation and Depression after Unilateral Labyrinthectomy in the Medial Vestibular Nucleus of Rats

2003 ◽  
Vol 123 (2) ◽  
pp. 182-186 ◽  
Author(s):  
Vito Enrico Pettorossi ◽  
Mayank Dutia ◽  
Adele Frondaroli ◽  
Cristina Dieni ◽  
Silvarosa Grassi
Keyword(s):  
Vestibular Nucleus ◽  
Long Term Potentiation ◽  
Medial Vestibular Nucleus ◽  
Term Potentiation ◽  
Unilateral Labyrinthectomy

scholarly journals Effects of Betahistine on the Development of Vestibular Compensation after Unilateral Labyrinthectomy in Rats

2021 ◽  
Vol 11 (3) ◽  
pp. 360
Author(s):  
Junya Fukuda ◽  
Kazunori Matsuda ◽  
Go Sato ◽  
Tadashi Kitahara ◽  
Momoyo Matsuoka ◽  
...  
Keyword(s):  
Vestibular Nucleus ◽  
Vestibular Compensation ◽  
Spontaneous Nystagmus ◽  
Medial Vestibular Nucleus ◽  
Dependent Manner ◽  
H3 Receptors ◽  
Unilateral Labyrinthectomy ◽  
Betahistine Dihydrochloride ◽  
Dose Dependent ◽  
Initial Process

Background: Vestibular compensation (VC) after unilateral labyrinthectomy (UL) consists of the initial and late processes. These processes can be evaluated based on the decline in the frequency of spontaneous nystagmus (SN) and the number of MK801-induced Fos-positive neurons in the contralateral medial vestibular nucleus (contra-MVe) in rats. Histamine H3 receptors (H3R) are reported to be involved in the development of VC. Objective: We examined the effects of betahistine, an H3R antagonist, on the initial and late processes of VC in UL rats. Methods: Betahistine dihydrochloride was continuously administered to the UL rats at doses of 100 and 200 mg/kg/day using an osmotic minipump. MK801 (1.0 mg/kg) was intraperitoneally administered on days 7, 10, 12, and 14 after UL, while Fos-positive neurons were immunohistochemically stained in the contra-MVe. Results: The SN disappeared after 42 h, and continuous infusion of betahistine did not change the decline in the frequency of SN. The number of MK801-induced Fos-positive neurons in contra-MVe significantly decreased on days 7, 10, and 12 after UL in a dose-dependent manner in the betahistine-treated rats, more so than in the saline-treated rats. Conclusion: These findings suggest that betahistine facilitated the late, but not the initial, process of VC in UL rats.

Comparison of protein kinase activity and protein phosphorylation in the medial vestibular nucleus and prepositus hypoglossi in labyrinthine-intact and labyrinthectomized guinea pigs

2000 ◽  
Vol 10 (2) ◽  
pp. 107-117
Author(s):  
DeWana R. Kerr ◽  
Andrew J. Sansom ◽  
Paul F. Smith ◽  
Cynthia L. Darlington
Keyword(s):  
Protein Kinase ◽  
Protein Phosphorylation ◽  
Guinea Pigs ◽  
Kinase Activity ◽  
Vestibular Nucleus ◽  
Vestibular Compensation ◽  
Medial Vestibular Nucleus ◽  
Protein Kinase Activity ◽  
Sham Operation ◽  
Prepositus Hypoglossi

The aim of the present study was to compare in vitro protein expression, protein kinase activity and protein phosphorylation in the medial vestibular nucleus (MVN) and prepositus hypoglossi (PH) from labyrinthine-intact guinea pigs and from guinea pigs at various stages of vestibular compensation following unilateral labyrinthectomy (UL). The ipsilateral (I-MVN) and contralateral (C-MVN) MVN, and the ipsilateral (I-PH) and contralateral (C-PH) PH, were dissected from 3 naive labyrinthine-intact guinea pigs and 55 guinea pigs at 10 hs or 53 hs following a surgical UL or sham operation. Tissue extracts were incubated with [gamma- 33 P]ATP ± Ca 2 + , phorbal 12, 13 dibutyrate and phosphatidylserine or ± Ca 2 + and calmodulin, to enhance protein kinase C (PKC) or calcium calmodulin kinase (CaMK) activity, respectively. Data were analysed as the ratio of activated to basal 33 P incorporation detected by phosphorimaging. There were similar total protein and phosphoprotein profiles in the MVN and PH, as well as both PKC and CaMKII activity, suggesting that the MVN and PH are similar in the way that proteins undergo rapid modification by phosphorylation. During the development of vestibular compensation, a 46 kDa band in C-PH displayed higher PKC-mediated phosphorylation from 10 hs post-UL compared to sham controls. Significantly greater PKC-mediated phosphorylation of proteins of approximately 18, 46 and 75 kDa was observed in C-PH at 10 hs compared to 53 hs post-UL and in most cases the phosphorylation was greater in C-PH than in the C-MVN. These results suggest that between 10 and 53 hs post-UL, PKC-mediated phosphorylation changes mainly in the C-PH rather than the ipsilateral or contralateral MVN.

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