scholarly journals A central mesencephalic reticular formation projection to medial rectus motoneurons supplying singly and multiply innervated extraocular muscle fibers

2017 ◽  
Vol 525 (8) ◽  
pp. 2000-2018 ◽  
Author(s):  
Martin O. Bohlen ◽  
Susan Warren ◽  
Paul J. May
Keyword(s):  
Reticular Formation ◽  
Extraocular Muscle ◽  
Muscle Fibers ◽  
Mesencephalic Reticular Formation ◽  
Medial Rectus ◽  
Central Mesencephalic Reticular Formation

scholarly journals Central mesencephalic reticular formation control of the near response: lens accommodation circuits

2019 ◽  
Vol 121 (5) ◽  
pp. 1692-1703 ◽  
Author(s):  
Paul J. May ◽  
Isabelle Billig ◽  
Paul D. Gamlin ◽  
Julie Quinet
Keyword(s):  
Rabies Virus ◽  
Reticular Formation ◽  
Formation Control ◽  
Present Report ◽  
Mesencephalic Reticular Formation ◽  
Time Frame ◽  
Medial Rectus ◽  
Depth Of Field ◽  
Central Mesencephalic Reticular Formation ◽  
Premotor Neurons

To view a nearby target, the three components of the near response are brought into play: 1) the eyes are converged through contraction of the medial rectus muscles to direct both foveae at the target, 2) the ciliary muscle contracts to allow the lens to thicken, increasing its refractive power to focus the near target on the retina, and 3) the pupil constricts to increase depth of field. In this study, we utilized retrograde transsynaptic transport of the N2c strain of rabies virus injected into the ciliary body of one eye of macaque monkeys to identify premotor neurons that control lens accommodation. We previously used this approach to label a premotor population located in the supraoculomotor area. In the present report, we describe a set of neurons located bilaterally in the central mesencephalic reticular formation that are labeled in the same time frame as the supraoculomotor area population, indicating their premotor character. The labeled premotor neurons are mostly multipolar cells, with long, very sparsely branched dendrites. They form a band that stretches across the core of the midbrain reticular formation. This population appears to be continuous with the premotor near-response neurons located in the supraoculomotor area at the level of the caudal central subdivision of the oculomotor nucleus. The central mesencephalic reticular formation has previously been associated with horizontal saccadic eye movements, so these premotor cells might be involved in controlling lens accommodation during disjunctive saccades. Alternatively, they may represent a population that controls vergence velocity. NEW & NOTEWORTHY This report uses transsynaptic transport of rabies virus to provide new evidence that the central mesencephalic reticular formation (cMRF) contains premotor neurons controlling lens accommodation. When combined with other recent reports that the cMRF also contains premotor neurons supplying medial rectus motoneurons, these results indicate that this portion of the reticular formation plays an important role in directing the near response and disjunctive saccades when viewers look between targets located at different distances.

scholarly journals A central mesencephalic reticular formation projection to the Edinger–Westphal nuclei

2015 ◽  
Vol 221 (8) ◽  
pp. 4073-4089 ◽  
Author(s):  
Paul J. May ◽  
Susan Warren ◽  
Martin O. Bohlen ◽  
Miriam Barnerssoi ◽  
Anja K. E. Horn
Keyword(s):  
Reticular Formation ◽  
Mesencephalic Reticular Formation ◽  
Central Mesencephalic Reticular Formation

Response Properties of Saccade-Related Burst Neurons in the Central Mesencephalic Reticular Formation

1997 ◽  
Vol 78 (4) ◽  
pp. 2164-2175 ◽  
Author(s):  
Ari Handel ◽  
Paul W. Glimcher
Keyword(s):  
Reticular Formation ◽  
Light Emitting Diode ◽  
Low Frequency ◽  
Mesencephalic Reticular Formation ◽  
Restricted Range ◽  
Response Properties ◽  
Burst Neurons ◽  
Central Mesencephalic Reticular Formation ◽  
Saccadic Target ◽  
Behaving Monkeys

Handel, Ari and Paul W. Glimcher. Response properties of saccade-related burst neurons in the central mesencephalic reticular formation. J. Neurophysiol. 78: 2164–2175, 1997. We studied the activity of saccade-related burst neurons in the central mesencephalic reticular formation (cMRF) in awake behaving monkeys. In experiment 1, we examined the activity of single neurons while monkeys performed an average of 225 delayed saccade trials that evoked gaze shifts having horizontal and vertical amplitudes between 2 and 20°. All neurons studied generated high-frequency bursts of activity during some of these saccades. For each neuron, the duration and frequency of these bursts of activity reached maximal values when the monkey made movements within a restricted range of horizontal and vertical amplitudes. The onset of the movement followed the onset of the burst by the longest intervals for movements within a restricted range of horizontal and vertical amplitudes. The range of movements for which this interval was longest varied from neuron to neuron. Across the population, these ranges included nearly all contraversive saccades with horizontal and vertical amplitudes between 2 and 20°. In experiment 2, we used the following task to examine the low-frequency prelude of activity that cMRF neurons generate before bursting: the monkey was required to fixate a light-emitting diode (LED) while two eccentric visual stimuli were presented. After a delay, the color of the fixation LED was changed, identifying one of the two eccentric stimuli as the saccadic target. After a final unpredictable delay, the fixation LED was extinguished and the monkey was reinforced for redirecting gaze to the identified saccadic target. Some cMRF neurons fired at a low frequency during the interval after the fixation LED changed color but before it was extinguished. For many neurons, the firing rate during this interval was related to the metrics of the movement the monkey made at the end of the trial and, to a lesser degree, to the location of the eccentric stimulus to which a movement was not directed.

Spatial characteristics of neurons in the central mesencephalic reticular formation (cMRF) of head-unrestrained monkeys

2005 ◽  
Vol 168 (4) ◽  
pp. 455-470 ◽  
Author(s):  
Jay S. Pathmanathan ◽  
Rachel Presnell ◽  
Jason A. Cromer ◽  
Kathleen E. Cullen ◽  
David M. Waitzman
Keyword(s):  
Reticular Formation ◽  
Mesencephalic Reticular Formation ◽  
Spatial Characteristics ◽  
Central Mesencephalic Reticular Formation
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