Birthdate-dependent heterogeneity of oculomotor neurons is involved in transmedian migration in the developing mouse midbrain

2018 ◽  
Vol 94 ◽  
pp. 32-38 ◽  
Author(s):  
Kohei Kawano ◽  
Hitoshi Gotoh ◽  
Tadashi Nomura ◽  
Katsuhiko Ono
Keyword(s):  
Oculomotor Neurons

scholarly journals A Study of Gene Expression Changes in Human Spinal and Oculomotor Neurons; Identifying Potential Links to Sporadic ALS

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 448
Author(s):  
Aayan N. Patel ◽  
Dennis Mathew
Keyword(s):  
Gene Expression ◽  
Disease Progression ◽  
Motor Neurons ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Tissue Samples ◽  
Disease Symptoms ◽  
Sporadic Als ◽  
Oculomotor Neurons ◽  
Als Patients

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that causes compromised function of motor neurons and neuronal death. However, oculomotor neurons are largely spared from disease symptoms. The underlying causes for sporadic ALS as well as for the resistance of oculomotor neurons to disease symptoms remain poorly understood. In this bioinformatic-analysis, we compared the gene expression profiles of spinal and oculomotor tissue samples from control individuals and sporadic ALS patients. We show that the genes GAD2 and GABRE (involved in GABA signaling), and CALB1 (involved in intracellular Ca2+ ion buffering) are downregulated in the spinal tissues of ALS patients, but their endogenous levels are higher in oculomotor tissues relative to the spinal tissues. Our results suggest that the downregulation of these genes and processes in spinal tissues are related to sporadic ALS disease progression and their upregulation in oculomotor neurons confer upon them resistance to ALS symptoms. These results build upon prevailing models of excitotoxicity that are relevant to sporadic ALS disease progression and point out unique opportunities for better understanding the progression of neurodegenerative properties associated with sporadic ALS.

Lesions of the posterior commissure disable the vertical neural integrator of the primate oculomotor system

1994 ◽  
Vol 71 (6) ◽  
pp. 2582-2585 ◽  
Author(s):  
A. M. Partsalis ◽  
S. M. Highstein ◽  
A. K. Moschovakis
Keyword(s):  
Eye Movements ◽  
Optokinetic Nystagmus ◽  
Head Rotation ◽  
Oculomotor System ◽  
Squirrel Monkeys ◽  
Neural Integrator ◽  
Posterior Commissure ◽  
Oculomotor Neurons ◽  
Before And After ◽  
Gain Reduction

1. Spontaneous saccades, vestibuloocular responses (VOR), and optokinetic nystagmus were recorded in three squirrel monkeys before and after chemical or electrolytic lesion of the posterior commissure (PC). 2. PC lesions produced abnormal vertical eye movements, in particular, 1) Postsaccadic drifts, and 2) VOR gain reduction and phase advance more pronounced at lower frequencies of sinusoidal head rotation. Horizontal eye movements were much less affected (or normal). 3. We conclude that PC fibers are necessary for conveying the output of the vertical neural integrator to vertical oculomotor-neurons.

Linear integration of convergent visual inputs in an oculomotor reflex pathway

1984 ◽  
Vol 52 (6) ◽  
pp. 1213-1225 ◽  
Author(s):  
R. M. Glantz ◽  
H. B. Nudelman ◽  
B. Waldrop
Keyword(s):  
Motor Neuron ◽  
Firing Rate ◽  
Motor Neurons ◽  
Receptive Fields ◽  
Polarized Light ◽  
Stray Light ◽  
Differential Sensitivity ◽  
Functional Connections ◽  
Cross Correlation Analysis ◽  
Oculomotor Neurons

The functional connectivity between identified visual interneurons [sustaining fibers (SF)] and oculomotor neurons was assessed by simultaneous recording and cross-correlation analysis. A small group of SFs exhibit excitatory functional connections to an identified tonic oculomotor neuron. The excitatory interactions are found exclusively between SFs and oculomotor neurons with similar and/or overlapping excitatory receptive fields. A second group of SFs exhibit inhibitory connections to motor neurons. The excitatory receptive fields of these SFs correspond to the inhibitory receptive fields of the motor neurons. The collective action of the SFs is sufficient to produce all of the steady-state visual behavior of the motor neurons including the increment in firing rate elicited by illumination, unique features of the motor neuron receptive field, and differential sensitivity to blue light and polarized light. Pairs of SFs that converge on the same motor neuron sum their effects linearly. Thus the joint interaction of two SFs on a motor neuron is equal to the sum of the two postsynaptic effects taken separately. Coactivation of excitatory and inhibitory SF inputs to a motor neuron results in a partial cancellation of their postsynaptic effects on the motor neuron's firing rate. The antagonistic interactions protect the system from perturbations by stray light, visual adaptation, and variations in the central excited state. The ensemble information code, at the SF level of the optomotor pathway, is a set of differentially weighted mean firing rates. The weightings reflect differences in the strengths of the several SF-to- motor neuron interactions. One consequence of these differences is a selective weighting of the effects of illumination (in different regions of visual space) on the compensatory eye reflex.

scholarly journals Cadherins regulate nuclear topography and function of developing ocular motor circuitry

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Athene Knüfer ◽  
Giovanni Diana ◽  
Gregory S Walsh ◽  
Jonathan DW Clarke ◽  
Sarah Guthrie
Keyword(s):  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Ocular Motor ◽  
Optokinetic Reflex ◽  
Classical Cadherins ◽  
Oculomotor Neurons ◽  
Dorsal Cells ◽  
And Function ◽  
Circuit Function

In the vertebrate central nervous system, groups of functionally related neurons, including cranial motor neurons of the brainstem, are frequently organised as nuclei. The molecular mechanisms governing the emergence of nuclear topography and circuit function are poorly understood. Here we investigate the role of cadherin-mediated adhesion in the development of zebrafish ocular motor (sub)nuclei. We find that developing ocular motor (sub)nuclei differentially express classical cadherins. Perturbing cadherin function in these neurons results in distinct defects in neuronal positioning, including scattering of dorsal cells and defective contralateral migration of ventral subnuclei. In addition, we show that cadherin-mediated interactions between adjacent subnuclei are critical for subnucleus position. We also find that disrupting cadherin adhesivity in dorsal oculomotor neurons impairs the larval optokinetic reflex, suggesting that neuronal clustering is important for co-ordinating circuit function. Our findings reveal that cadherins regulate distinct aspects of cranial motor neuron positioning and establish subnuclear topography and motor function.

scholarly journals Modeling motor neuron resilience in ALS using stem cells

2018 ◽  
Author(s):  
Ilary Allodi ◽  
Jik Nijssen ◽  
Julio Aguila Benitez ◽  
Christoph Schweingruber ◽  
Andrea Fuchs ◽  
...  
Keyword(s):  
Stem Cells ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Embryonic Stem ◽  
Spinal Motor Neurons ◽  
Neuronal Progenitors ◽  
Oculomotor Neurons ◽  
Bona Fide

SUMMARYOculomotor neurons, which regulate eye movement, are resilient to degeneration in the lethal motor neuron disease amyotrophic lateral sclerosis (ALS). It would be highly advantageous if motor neuron resilience could be modeled in vitro. Towards this goal, we generated a high proportion of oculomotor neurons from mouse embryonic stem cells through temporal overexpression of Phox2a in neuronal progenitors. We demonstrate, using electrophysiology, immunocytochemistry and RNA sequencing, that in vitro generated neurons are bona fide oculomotor neurons based on their cellular properties and similarity to their in vivo counterpart in rodent and man. We also show that in vitro generated oculomotor neurons display a robust activation of survival-promoting Akt signaling and are more resilient to the ALS-like toxicity of kainic acid than spinal motor neurons. Thus, we can generate bona fide oculomotor neurons in vitro which display a resilience similar to that seen in vivo.

GDNF increases the survival of developing oculomotor neurons through a target-derived mechanism

2003 ◽  
Vol 24 (1) ◽  
pp. 41-56 ◽  
Author(s):  
Jennifer Chen ◽  
Rafal Butowt ◽  
Howard B Rind ◽  
Christopher S von Bartheld
Keyword(s):  
Oculomotor Neurons
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