scholarly journals The Effect of Variations in Ionic Conductance Values on the Suppression of Repetitive Spiking in a Mathematical Model of Type-A Medial Vestibular Nucleus Neurons

2016 ◽  
Vol 07 (10) ◽  
pp. 1134-1139 ◽  
Author(s):  
Takaaki Shirahata
Keyword(s):  
Mathematical Model ◽  
Vestibular Nucleus ◽  
Type A ◽  
Medial Vestibular Nucleus ◽  
Ionic Conductance

Static and Dynamic Membrane Properties of Lateral Vestibular Nucleus Neurons in Guinea Pig Brain Stem Slices

2003 ◽  
Vol 90 (3) ◽  
pp. 1689-1703 ◽  
Author(s):  
Atsuhiko Uno ◽  
Erwin Idoux ◽  
Mathieu Beraneck ◽  
Pierre-Paul Vidal ◽  
Lee E. Moore ◽  
...  
Keyword(s):  
Vestibular Nucleus ◽  
Type A ◽  
Membrane Properties ◽  
In Vivo Studies ◽  
Medial Vestibular Nucleus ◽  
Intracellular Recordings ◽  
Lateral Vestibular Nucleus ◽  
Type B ◽  
Dynamic Membrane ◽  
Homogeneous Population

In vitro intracellular recordings of central vestibular neurons have been restricted so far to the medial vestibular nucleus (MVN). We performed intracellular recordings of large Deiters' neurons in the lateral vestibular nucleus (LVN) to determine their static and dynamic membrane properties, and compare them with those of type A and type B neurons identified in the MVN. Unlike MVN neurons (MVNn), the giant-size LVN neurons (LVNn) form a homogeneous population of cells characterized by sharp spikes, a low-amplitude, biphasic after-hyperpolarization like type B MVNn, but also an A-like rectification like type A MVNn. In accordance with their lower membrane resistance, the sensitivity of LVNn to current injection was lower than that of MVNn over a large range of frequencies. The main difference between LVNn and MVNn was that the Bode plots showing the sensitivity of LVNn as a function of stimulation frequency were flatter than those of MVNn, and displayed a weaker resonance. Furthermore, most LVNn did not show a gradual decrease of their firing rate modulation in the frequency range where it was observed in MVNn. LVNn synchronized their firing with the depolarizing phase of high-frequency sinusoidal current injections. In vivo studies have shown that the MVN would be mainly involved in gaze control, whereas the giant LVNn that project to the spinal cord are involved in the control of posture. We suggest that the difference in the membrane properties of LVNn and MVNn may reflect their specific physiological roles.

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.

Inhibitory Synaptic Transmission Differs in Mouse Type A and B Medial Vestibular Nucleus Neurons In Vitro

2006 ◽  
Vol 95 (5) ◽  
pp. 3208-3218 ◽  
Author(s):  
Aaron J. Camp ◽  
Robert J. Callister ◽  
Alan M. Brichta
Keyword(s):  
Synaptic Transmission ◽  
Vestibular Nucleus ◽  
Type A ◽  
Mean Amplitude ◽  
Medial Vestibular Nucleus ◽  
Type B ◽  
Inhibitory Synaptic Transmission ◽  
Relative Contribution ◽  
Whole Cell Patch Clamp

Fast inhibitory synaptic transmission in the medial vestibular nucleus (MVN) is mediated by GABAA receptors (GABAARs) and glycine receptors (GlyRs). To assess their relative contribution to inhibition in the MVN, we recorded miniature inhibitory postsynaptic currents (mIPSCs) in physiologically characterized type A and type B MVN neurons. Transverse brain stem slices were prepared from mice (3–8 wk old), and whole cell patch-clamp recordings were obtained from visualized MVN neurons (CsCl internal; Vm = –70 mV; 23°C). In 81 MVN neurons, 69% received exclusively GABAAergic inputs, 6% exclusively glycinergic inputs, and 25% received both types of mIPSCs. The mean amplitude of GABAAR-mediated mIPSCs was smaller than those mediated by GlyRs (22.6 ± 1.8 vs. 35.3 ± 5.3 pA). The rise time and decay time constants of GABAAR- versus GlyR-mediated mIPSCs were slower (1.3 ± 0.1 vs. 0.9 ± 0.1 ms and 10.5 ± 0.3 vs. 4.7 ± 0.3 ms, respectively). Comparison of type A ( n = 20) and type B ( n = 32) neurons showed that type A neurons received almost exclusively GABAAergic inhibitory inputs, whereas type B neurons received GABAAergic inputs, glycinergic inputs, or both. Intracellular labeling in a subset of MVN neurons showed that morphology was not related to a MVN neuron's inhibitory profile ( n = 15), or whether it was classified as type A or B ( n = 29). Together, these findings indicate that both GABA and glycine contribute to inhibitory synaptic processing in MVN neurons, although GABA dominates and there is a difference in the distribution of GABAA and Gly receptors between type A and type B MVN neurons.

Excitation and inhibition of rat medial vestibular nucleus neurones by 5-hydroxytryptamine

1993 ◽  
Vol 93 (2) ◽  
Author(s):  
A.R. Johnston ◽  
Bridin Murnion ◽  
D.S. McQueen ◽  
M.B. Dutia
Keyword(s):  
Vestibular Nucleus ◽  
Medial Vestibular Nucleus

Plasticity of γ-aminobutyrate receptors in the medial vestibular nucleus of rat after inferior cerebellar peduncle transection

2002 ◽  
Vol 12 (1) ◽  
pp. 1-14
Author(s):  
Yizhe Sun ◽  
Donald A. Godfrey ◽  
Allan M. Rubin
Keyword(s):  
Vestibular Nucleus ◽  
Brain Slices ◽  
Medial Vestibular Nucleus ◽  
Grouped Data ◽  
Spontaneous Firing ◽  
Gaba A ◽  
Endogenous Gaba ◽  
Single Unit Recordings ◽  
Cerebellar Peduncle ◽  
Inferior Cerebellar Peduncle

Extracellular single unit recordings were made from regularly discharging medial vestibular nucleus neurons in brain slices from control rats and from rats surviving 7 days after bilateral transection of the inferior cerebellar peduncle. Decreases in firing rate during perfusion with the Îş-aminobutyric acid (GABA) agonists, muscimol (GABA A ) and baclofen (GABA B ), were greater in lesioned rats than in control rats. For the grouped data, the half-maximally-effective concentrations of muscimol and baclofen were 3.2 µM, as compared with 19.6 µM for control, and 0.8 µM, as compared with 2.7 µM for control, respectively. The antagonists bicuculline (GABA A ) and 2-OH-saclofen (GABA B ) only minimally affected the spontaneous firing rates of neurons in lesioned rats, significantly less than in control rats. The data suggest that the decreases of endogenous GABA levels in the medial vestibular nucleus after inferior cerebellar peduncle transection are accompanied by up-regulation of GABA A and, to a lesser extent, GABA B receptors.

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.

Measurement of 5-hydroxytryptamine release in the rat medial vestibular nucleus using in vivo microdialysis

2002 ◽  
Vol 323 (3) ◽  
pp. 234-238 ◽  
Author(s):  
Shino Inoue ◽  
Taizo Kita ◽  
Toshiaki Yamanaka ◽  
Yohichi Ogawa ◽  
Toshikatsu Nakashima ◽  
...  
Keyword(s):  
Vestibular Nucleus ◽  
In Vivo Microdialysis ◽  
Medial Vestibular Nucleus
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