Morphology and connections of intratrigeminal cells and axons in the macaque monkey

Warren, Susan; May, Paul J.

doi:10.3389/fnana.2013.00011

Cited by 8 publications

(8 citation statements)

References 65 publications

(110 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They found that the injection reduced frequency and amplitude of spontaneous eye movement in both the treated and non-treated eyes and concluded that proprioceptive sensory signals from one eye are used to modulate movements of the other eye. This is consistent with the fact that the unilateral trigeminal inputs are distributed bilaterally by trigemino-trigeminal projections (Warren & May, 2013).…”

Section: Discussionsupporting

confidence: 89%

Passive eye movements induced by electromagnetic force (EMF) in rats

Huang

Zhang

et al. 2019

Zoological Research

Self Cite

View full text Add to dashboard Cite

Accurate information on eye position in the orbit is available from visual feedback, efference copy of the oculomotor commands and proprioceptive signals from the extraocular muscles (EOM). Whereas visual feedback and oculomotor commands have been extensively studied, central processing of EOM proprioceptive signals remains to be elucidated. A challenge to the field is to develop an approach to induce passive eye movements without physically contacting the eyes. A novel method was developed to generate passive eye movements in rats. A small rare-earth magnet disk (0.7 mm diameter, 0.5 mm thickness) was attached to the surface of a rat’s eyeball. A metal rod (5 mm diameter) wrapped with an electromagnetic (EM) coil was placed near the magnet (8–15 mm). By passing currents to the EM coil, electromagnetic force (EMF) was generated and acted upon the magnet and induced passive eye movements. The EMF induced well-defined passive eye movements, whose directions were dependent on current polarity and amplitudes and peak velocities were dependent on current intensity and duration. Peak velocities of the EMF-induced eye movements were linearly related to amplitudes, exhibiting main sequence relationships similar to that of saccades in awake rats and eye movements induced by electrical microstimulation of the abducens nucleus in anesthetized rats. Histological examination showed that repetitive EMF stimulations did not appear to result in damages in the EOM fibers. These results validated the EMF approach as a novel tool to investigate EOM proprioceptive signals and their roles in visual localization and gaze control.

show abstract

Section: Discussionsupporting

confidence: 89%

Passive eye movements induced by electromagnetic force (EMF) in rats

Huang

Zhang

et al. 2019

Zoological Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…Rostral and caudal regions of the TBNC are connected through a dense longitudinal fiber system [206–209]. Evidence that intersubnuclear pathways serve a “feed forward” facilitatory function has been reported in models for acute dental pain [210], headache [211] and evoked eye blinks [212]; however, a role in DED has not been determined.…”

Section: Neurobiological Features In Normal/non Dry Eye Diseasementioning

confidence: 99%

TFOS DEWS II pain and sensation report

et al. 2017

View full text Add to dashboard Cite

Pain associated to mechanical and chemical irritation of the eye surface is mediated by trigeminal ganglia mechano- and polymodal nociceptor neurons while cold thermoreceptors detect wetness and reflexly maintain basal tear production and blinking rate. These neurons project into two regions of the trigeminal brain stem nuclear complex: ViVc, activated by changes in the moisture of the ocular surface and VcC1, mediating sensory-discriminative aspects of ocular pain and reflex blinking. ViVc ocular neurons project to brain regions that control lacrimation and spontaneous blinking and to the sensory thalamus. Secretion of the main lacrimal gland is regulated dominantly by autonomic parasympathetic nerves, reflexly activated by eye surface sensory nerves. These also evoke goblet cell secretion through unidentified efferent fibers. Neural pathways involved in the regulation of Meibonian gland secretion or mucins release have not been identified. In dry eye disease, reduced tear secretion leads to inflammation and peripheral nerve damage. Inflammation causes sensitization of polymodal and mechano-nociceptor nerve endings and an abnormal increase in cold thermoreceptor activity, altogether evoking dryness sensations and pain. Long-term inflammation and nerve injury alter gene expression of ion channels and receptors at terminals and cell bodies of trigeminal ganglion and brainstem neurons, changing their excitability, connectivity and impulse firing. Perpetuation of molecular, structural and functional disturbances in ocular sensory pathways ultimately leads to dysestesias and neuropathic pain referred to the eye surface. Pain can be assessed with a variety of questionaires while the status of corneal nerves is evaluated with esthesiometry and with in vivo confocal microscopy.

show abstract

“…As this injection site included pV, and we have documented the presence of extensive intratrigeminal connection in the macaque (Warren & May, 2013), we tested whether the cells labeled in Case 1 might be trigeminotrigeminal neurons by injecting WGA‐HRP into pV (Case 2). Figure 3 shows the pattern of brainstem labeling in a case where the WGA‐HRP injection site involved pV, but did not involve VII (Figure 3a–c).…”

Section: Resultsmentioning

confidence: 99%

Macaque monkey trigeminal blink reflex circuits targeting orbicularis oculi motoneurons

May

Warren

2021

J of Comparative Neurology

Self Cite

View full text Add to dashboard Cite

The trigeminal blink reflex plays an important role in protecting the corneal surface from damage and preserving visual function in an unpredictable environment. The closing phase of the human reflex, produced by activation of the orbicularis oculi (ObOc) muscles, consists of an initial, small, ipsilateral R 1 component, followed by a larger, bilateral R 2 component. We investigated the circuitry that underlies this reflex in macaque (Macaca fascicularis and Macaca mulatta) monkeys by the use of single and dual tracer methods. Injection of retrograde tracer into the facial nucleus labeled neurons in the principal trigeminal nucleus, and in the spinal nucleus pars oralis and interpolaris, bilaterally, and in pars caudalis, ipsilaterally. Injection of anterograde tracer into the principal trigeminal nucleus labeled axons that directly terminated on ObOc motoneurons, with an ipsilateral predominance. Injection of anterograde tracer into pars caudalis of the spinal trigeminal nucleus labeled axons that directly terminated on ipsilateral ObOc motoneurons. The observed pattern of labeling indicates that the reticular formation ventromedial to the principal and spinal nuclei also contributes extensive bilateral input to ObOc motoneurons. Thus, much of the trigeminal sensory complex is in a position to supply a monosynaptic drive for lid closure, and the adjacent reticular formation can supply a disynaptic drive. These findings indicate that the assignment of the R 1 and R 2 components of the blink reflex to different parts of the trigeminal sensory complex cannot be exclusively based on subdivision connectional relationships with facial motoneurons. The characteristics of the R 2 component may be due, instead, to other circuit properties.

show abstract

Morphology and connections of intratrigeminal cells and axons in the macaque monkey

Cited by 8 publications

References 65 publications

Passive eye movements induced by electromagnetic force (EMF) in rats

Passive eye movements induced by electromagnetic force (EMF) in rats

TFOS DEWS II pain and sensation report

Macaque monkey trigeminal blink reflex circuits targeting orbicularis oculi motoneurons

Contact Info

Product

Resources

About