scholarly journals Central pupillary light reflex circuits in the cat: I. The olivary pretectal nucleus

2014 ◽  
Vol 522 (18) ◽  
pp. 3960-3977 ◽  
Author(s):  
Wensi Sun ◽  
Paul J. May
Keyword(s):  
Pupillary Light Reflex ◽  
Light Reflex ◽  
Pupillary Light ◽  
Pretectal Nucleus

Primate Pupillary Light Reflex: Receptive Field Characteristics of Pretectal Luminance Neurons

2003 ◽  
Vol 89 (6) ◽  
pp. 3168-3178 ◽  
Author(s):  
Robert J. Clarke ◽  
Hongyu Zhang ◽  
Paul D. R. Gamlin
Keyword(s):  
Receptive Fields ◽  
Pupillary Light Reflex ◽  
Central Visual Field ◽  
Light Reflex ◽  
Pupillary Light ◽  
Pupillary Responses ◽  
Retinal Input ◽  
Pretectal Nucleus ◽  
Luminance Stimulus ◽  
Olivary Nucleus

This study examined the response properties of luminance neurons found within the pretectal olivary nucleus (PON), which is the pretectal nucleus that mediates the primate pupillary light reflex. We recorded the activity of 121 single units in alert, behaving rhesus monkeys trained to fixate a back-projected laser spot while a luminance stimulus was presented. The change in the firing rate of luminance neurons was measured as a function of changes in the size, retinal illuminance, and position of the stimulus. We found that these neurons possessed large receptive fields, which were sufficiently distinct that they could be placed into three classes. Approximately 40% of the PON luminance neurons responded well to stimuli presented in either the contralateral or ipsilateral hemifield. These neurons were classified as “bilateral” neurons. In the primate, retinal projections to the pretectum and other retinorecipient nuclei are organized such that direct retinal input can only account for the contralateral hemifield responses of these neurons. Thus the representation of the ipsilateral hemifield in “bilateral” PON cells must result from input from a nonretinal source. Approximately 30% of PON neurons responded only to stimuli presented in the contralateral hemifield. These neurons were classified as “contralateral” neurons. Finally, approximately 30% of PON neurons responded to stimuli presented at or near the animal's fixation point. These neurons were classified as “macular” neurons. The mean firing rates of all classes of neurons increased with increases in stimulus size and luminance within their receptive fields. The thresholds and magnitude of these responses closely matched those that would be appropriate for mediating the pupillary light reflex. In summary, these results suggest that all three classes of PON neurons contribute to the behaviorally observed pupillomotor field characteristics in which stimuli at the macular produce substantially larger pupillary responses than more peripheral stimuli. The contributions of “bilateral” and “contralateral” cells account for pupillary responses evoked by peripheral changes in luminance, whereas the contributions of all three cell classes account for the larger pupillary responses evoked by stimuli in the central visual field.

scholarly journals Pupillary light reflex circuits in the macaque monkey: the preganglionic Edinger–Westphal nucleus

2019 ◽  
Vol 225 (1) ◽  
pp. 403-425 ◽  
Author(s):  
Paul J. May ◽  
Wensi Sun ◽  
Nicholas F. Wright ◽  
Jonathan T. Erichsen
Keyword(s):  
Macaque Monkey ◽  
Pupillary Light Reflex ◽  
Cerebral Aqueduct ◽  
Ciliary Ganglion ◽  
Cell Column ◽  
Light Reflex ◽  
Pupillary Light ◽  
Pretectal Nucleus ◽  
Spherical Vesicles ◽  
Edinger Westphal Nucleus

AbstractThe motor outflow for the pupillary light reflex originates in the preganglionic motoneuron subdivision of the Edinger–Westphal nucleus (EWpg), which also mediates lens accommodation. Despite their importance for vision, the morphology, ultrastructure and luminance-related inputs of these motoneurons have not been fully described in primates. In macaque monkeys, we labeled EWpg motoneurons from ciliary ganglion and orbital injections. Both approaches indicated preganglionic motoneurons occupy an EWpg organized as a unitary, ipsilateral cell column. When tracers were placed in the pretectal complex, labeled terminals targeted the ipsilateral EWpg and reached contralateral EWpg by crossing both above and below the cerebral aqueduct. They also terminated in the lateral visceral column, a ventrolateral periaqueductal gray region containing neurons projecting to the contralateral pretectum. Combining olivary pretectal and ciliary ganglion injections to determine whether a direct pupillary light reflex projection is present revealed a labeled motoneuron subpopulation that displayed close associations with labeled pretectal terminal boutons. Ultrastructurally, this subpopulation received synaptic contacts from labeled pretectal terminals that contained numerous clear spherical vesicles, suggesting excitation, and scattered dense-core vesicles, suggesting peptidergic co-transmitters. A variety of axon terminal classes, some of which may serve the near response, synapsed on preganglionic motoneurons. Quantitative analysis indicated that pupillary motoneurons receive more inhibitory inputs than lens motoneurons. To summarize, the pupillary light reflex circuit utilizes a monosynaptic, excitatory, bilateral pretectal projection to a distinct subpopulation of EWpg motoneurons. Furthermore, the interconnections between the lateral visceral column and olivary pretectal nucleus may provide pretectal cells with bilateral retinal fields.

scholarly journals Normal behavioral responses to light and darkness and the pupillary light reflex are dependent upon the olivary pretectal nucleus in the diurnal Nile grass rat

Neuroscience ◽  
2017 ◽  
Vol 355 ◽  
pp. 225-237 ◽  
Author(s):  
Andrew J. Gall ◽  
Ohanes S. Khacherian ◽  
Brandi Ledbetter ◽  
Sean P. Deats ◽  
Megan Luck ◽  
...  
Keyword(s):  
Behavioral Responses ◽  
Pupillary Light Reflex ◽  
Light Reflex ◽  
Pupillary Light ◽  
Pretectal Nucleus

scholarly journals Effect of Topical Anti-Glaucoma Medications on Late Pupillary Light Reflex, as Evaluated by Pupillometry

2015 ◽  
Vol 6 ◽  
Author(s):  
Shakoor Ba-Ali ◽  
Birgit Sander ◽  
Adam Elias Brøndsted ◽  
Henrik Lund-Andersen
Keyword(s):  
Pupillary Light Reflex ◽  
Light Reflex ◽  
Pupillary Light
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