Developmental changes in the electrophysiological properties of neonatal rat oculomotor neurons studied in vitro

Tsuzuki, Shosai; Yoshida, Shigeru; Yamamoto, Tetsuro; Oka, Hiroshi

doi:10.1016/0168-0102(95)00966-w

Cited by 28 publications

(26 citation statements)

References 20 publications

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“…The age-related changes in membrane properties that underlie bursting in dorsal NVsnpr neurons ( Brocard et al, 2006 ) are similar to those that occur in the more ventral whisker region of NVsnpr ( Lo and Erzurumlu, 2001 ), the spinal trigeminal nucleus ( Guido et al, 1998 ) and in several other brainstem regions of the rat ( Nunez-Abades et al, 1993 ;Bao et al, 1995 ;Tsuzuki et al, 1995 ;Berger et al, 1996 ;Tanaka et al, 2003 ;Nguyen et al, 2004 ). This suggests that the maturation process of neurons in many brainstem nuclei is similar.…”

Section: Ontogenesis Of Sucking and Chewingmentioning

confidence: 53%

Central pattern generators for orofacial movements and speech

Barlow¹,

Radder²,

Radder³

et al. 2010

Handbook of Behavioral Neuroscience

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Section: Ontogenesis Of Sucking and Chewingmentioning

confidence: 53%

Central pattern generators for orofacial movements and speech

Barlow¹,

Radder²,

Radder³

et al. 2010

Handbook of Behavioral Neuroscience

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“…Type II Mns failed to maintain their repetitive discharge longer than 300 ms after stimulus onset. We found type II Mns in lower percentages, in both neonatal and adult periods, than did earlier works (Gueritaud, 1988; Tsuzuki et al ., 1995). Furthermore, this repetitive discharge pattern has also been identified in abducens, spinal cord, and facial Mns (Fulton & Walton, 1986; Durand, 1989a; Magarinos‐Ascone et al ., 1999), as well as in other nuclei (Saito & Isa, 1999; Ruscheweyh & Sandkühler, 2002; Straka et al ., 2004; Laursen & Rekling, 2006).…”

Section: Discussionmentioning

confidence: 77%

“…Studies on Mns of the oculomotor and abducens nuclei in the brain slice preparation have shown sustained, transient, and delayed discharge patterns (Gueritaud, 1988; Tsuzuki et al ., 1995; Russier et al ., 2003). The firing properties have been studied in detail, using in vitro preparations in rodents' vestibular nucleus (reviewed in Straka et al ., 2005), which are of particular interest here because some of these neurons are a major source of direct projections to oculomotor Mns (Carpenter, 1988).…”

Section: Introductionmentioning

confidence: 99%

Phasic and tonic firing properties in rat oculomotor nucleus motoneurons, studied in vitro

Nieto-González¹,

Carrascal²,

Nuñez-Abades³

et al. 2007

Eur J of Neuroscience

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Alert-chronic studies show that ocular motoneurons (Mns) exhibit a phasic and tonic firing correlated with eye saccade-velocity and position (fixation), respectively. Differences in the phasic and tonic firing among Mns depend on synaptic inputs and/or the intrinsic membrane properties. We have used in vitro slice preparation to investigate the contribution of membrane properties to firing properties of Wistar rat oculomotor nucleus Mns. We recorded different discharge patterns and focused on Mns with sustained discharge (type I) because they were the most abundant, and their firing pattern resembles that reported in alert preparations. Various differences divided these Mns into types I(A) and I(B); the afterhyperpolarization (AHP) phase of the spike was monophasic in I(A) and biphasic in I(B); I(A) Mns showed tonic or phasic-tonic firing depending on the current intensity, while I(B) Mns showed phasic-tonic discharge; the phasic firing was higher in I(B) than in I(A) Mns; I(A) Mns fired in a narrower range than did I(B) Mns; and I(A) Mns showed lower maximum frequency than did I(B) Mns. In conclusion, I(A) and I(B) Mns show different phasic firing properties and dynamic range, supported by intrinsic membrane properties. We suggest that I(A) and I(B) Mns innervate fast-twitch muscle fibres with different contraction speeds, and could contribute to generating a fine phasic signal for a graded muscle contraction. Finally, we have demonstrated an inverse relationship between Mn thresholds and tonic firing gain, concluding that intrinsic membrane properties could not support the covariation between tonic firing gain and recruitment thresholds reported in alert studies.

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“…Already in WT animals, electrophysiological properties of MNs change significantly during development in a functionally relevant manner, e.g. 2‐ to 3‐week‐old MNs display shorter AP durations, increased cAHP amplitudes or decreased input resistances in comparison to P0–5 MNs (Viana et al 1994; Tsuzuki et al 1995; Berger et al 1996; Carrascal et al 2006; Quinlan et al 2011). For mouse HMNs, patch‐clamp data have been reported up to P10 (van Zundert et al 2008), but a recent in vitro description (Mitra & Brownstone, 2011) and in vivo intracellular recordings of adult spinal MNs (Manuel et al 2009; Meehan et al 2010 b ) suggested ongoing developmental changes of membrane properties after this early juvenile age.…”

Section: Discussionmentioning

confidence: 99%

Selective mitochondrial Ca²⁺ uptake deficit in disease endstage vulnerable motoneurons of the SOD1^G93A mouse model of amyotrophic lateral sclerosis

Fuchs

Kutterer

Mühling

et al. 2013

The Journal of Physiology

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Key points• So far, increased excitability and calcium handling problems have been discussed as causes for motoneuron death in amyotrophic lateral sclerosis (ALS) mainly on the basis of studies in juvenile presymptomatic mice.• We developed a brainstem preparation to analyse excitability and calcium handling during disease progression up to disease endstage of motoneurons in an ALS mouse model. • Increased excitability of motoneurons is not seen at disease endstage, challenging this factor as a direct cause for motoneuron death in ALS.• We show that calcium handling is remodelled during disease progression from mitochondrial uptake to mitochondrial uptake failure and increased plasma membrane extrusion, providing a compensatory mechanism that fails at disease endstage and might lead to a toxic calcium overload of the cells. • Supporting this newly described compensatory endeavour of the motoneurons might be a promising therapeutic strategy.Abstract Amyotrophic lateral sclerosis is a progressive neurodegenerative disease that targets some somatic motoneuron populations, while others, e.g. those of the oculomotor system, are spared. The pathophysiological basis of this pattern of differential vulnerability, which is preserved in a transgenic mouse model of amyotrophic lateral sclerosis (SOD1 G93A ), and the mechanism of neurodegeneration in general are unknown. Hyperexcitability and calcium dysregulation have been proposed by others on the basis of data from juvenile mice that are, however, asymptomatic. No studies have been done with symptomatic mice following disease progression to the disease endstage. Here, we developed a new brainstem slice preparation for whole-cell patch-clamp recordings and single cell fura-2 calcium imaging to study motoneurons in adult wild-type and SOD1 G93A mice up to disease endstage. We analysed disease-stage-dependent electrophysiological properties and intracellular Ca 2+ handling of vulnerable hypoglossal motoneurons in comparison to resistant oculomotor neurons. Thereby, we identified a transient hyperexcitability in presymptomatic but not in endstage vulnerable motoneurons. Additionally, we revealed a remodelling of intracellular Ca 2+ clearance within vulnerable but not resistant motoneurons at disease endstage characterised by a reduction of uniporter-dependent mitochondrial Ca 2+ uptake and enhanced Ca 2+ extrusion across the plasma membrane. Our study challenged the notion that hyperexcitability is a direct cause

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Developmental changes in the electrophysiological properties of neonatal rat oculomotor neurons studied in vitro

Cited by 28 publications

References 20 publications

Central pattern generators for orofacial movements and speech

Central pattern generators for orofacial movements and speech

Phasic and tonic firing properties in rat oculomotor nucleus motoneurons, studied in vitro

Selective mitochondrial Ca²⁺ uptake deficit in disease endstage vulnerable motoneurons of the SOD1^G93A mouse model of amyotrophic lateral sclerosis

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Developmental changes in the electrophysiological properties of neonatal rat oculomotor neurons studied in vitro

Cited by 28 publications

References 20 publications

Central pattern generators for orofacial movements and speech

Central pattern generators for orofacial movements and speech

Phasic and tonic firing properties in rat oculomotor nucleus motoneurons, studied in vitro

Selective mitochondrial Ca2+ uptake deficit in disease endstage vulnerable motoneurons of the SOD1G93A mouse model of amyotrophic lateral sclerosis

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Selective mitochondrial Ca²⁺ uptake deficit in disease endstage vulnerable motoneurons of the SOD1^G93A mouse model of amyotrophic lateral sclerosis