Faculty Opinions recommendation of Experiential modification of the trigeminal reflex blink circuit.

2007 ◽  
Author(s):  
Michele A Basso
Keyword(s):  
Reflex Blink ◽  
Trigeminal Reflex

scholarly journals Sex, blinking, and dry eye

2020 ◽  
Vol 123 (2) ◽  
pp. 831-842
Author(s):  
Ashley Culoso ◽  
Cynthia Lowe ◽  
Craig Evinger
Keyword(s):  
Dry Eye ◽  
Tear Film ◽  
Focal Dystonia ◽  
Female Rats ◽  
Sexually Dimorphic ◽  
Blink Rate ◽  
Sexual Dimorphisms ◽  
Essential Blepharospasm ◽  
Reflex Blink ◽  
Trigeminal Reflex

Blinking sustains the corneal tear film generated by sexually dimorphic lacrimal and meibomian glands. Our study examines whether trigeminal control of blinking is also sexually dimorphic by investigating trigeminal reflex blinking, associative blink modification, and spontaneous blinking in male and female rats before and after unilateral dry eye caused by exorbital gland removal. Before gland removal, female rats exhibited a lower threshold for evoking trigeminal reflex blinks, a weaker effect of associative blink modification, and longer-duration spontaneous blinks than males. Spontaneous blink rate, reflex blink excitability, and occurrence of blink oscillations did not differ between the sexes. Reanalysis of previous data showed that humans showed the same blink sexual dimorphisms as rats. During the first 2 wk of dry eye, trigeminal blink circuit excitability and blink oscillations steadily rose in male rats, whereas excitability and blink oscillations did not change in females. Following dry eye, spontaneous blink duration increased for both males and females, whereas spontaneous blink rate remained constant for males but decreased for females. The associative modification treatment to depress trigeminal blink amplitude initially produced blink depression in males that converted to blink potentiation as trigeminal excitability rose, whereas females exhibited progressively more blink depression. These data indicated that dry eye increased excitability in male trigeminal reflex blink circuits at the expense of circuit modifiability, whereas trigeminal modifiability increased in females. This increased modifiability of female trigeminal blink circuits with dry eye may contribute to the preponderance of females developing the focal dystonia, benign essential blepharospasm. NEW & NOTEWORTHY All the elements controlling the corneal tear film are sexually dimorphic. Blinking, which smooths and maintains the tear film, also exhibits sex differences. Dry eye increases the sexual dimorphisms of blinking, including increased exaggeration of excitability in males and enhanced modifiability of the female trigeminal complex. This increased modifiability may explain female predominance in the development of the focal dystonia, benign essential blepharospasm.

Animal Model Explains the Origins of the Cranial Dystonia Benign Essential Blepharospasm

1997 ◽  
Vol 77 (5) ◽  
pp. 2842-2846 ◽  
Author(s):  
Edward J. Schicatano ◽  
Michele A. Basso ◽  
Craig Evinger
Keyword(s):  
Animal Model ◽  
Factor Model ◽  
Tonic Inhibition ◽  
Striatal Dopamine ◽  
Dopamine Depletion ◽  
Orbicularis Oculi Muscle ◽  
Essential Blepharospasm ◽  
Reflex Blink ◽  
Striatal Dopamine Depletion ◽  
Trigeminal Reflex

Schicatano, Edward J., Michele A. Basso, and Craig Evinger. Animal model explains the origins of the cranial dystonia benign essential blepharospasm. J. Neurophysiol. 77: 2842–2846, 1997. The current study demonstrates that combining two mild alterations to the rat trigeminal reflex blink system reproduces the symptoms of benign essential blepharospasm, a cranial dystonia characterized by uncontrollable spasms of blinking. The first modification, a small striatal dopamine depletion, reduces the tonic inhibition of trigeminal reflex blink circuits. The second alteration, a slight weakening of the lid-closing orbicularis oculi muscle, begins an adaptive increase in the drive on trigeminal sensory-motor blink circuits that initiates blepharospasm. By themselves, neither of these modifications causes spasms of lid closure, but combined, they induce bilateral forceful blinking and spasms of lid closure. A two-factor model based on these rodent experiments may explain the development of benign essential blepharospasm in humans. The first factor, a subclinical loss of striatal dopamine, creates a permissive environment within the trigeminal blink circuits. The second factor, an external ophthalmic insult, precipitates benign essential blepharospasm. This two-factor model may also be applicable to the genesis of other cranial dystonias.

scholarly journals Experiential Modification of the Trigeminal Reflex Blink Circuit

2007 ◽  
Vol 27 (39) ◽  
pp. 10414-10422 ◽  
Author(s):  
C. Dauvergne ◽  
C. Evinger
Keyword(s):  
Reflex Blink ◽  
Trigeminal Reflex

scholarly journals Analysis of NOS Gene Polymorphisms in Relation to Cluster Headache and Predisposing Factors in Sweden

2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Caroline Ran ◽  
Julia M. Michalska ◽  
Carmen Fourier ◽  
Christina Sjöstrand ◽  
Elisabet Waldenlind ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cluster Headache ◽  
Genetic Variants ◽  
Potential Candidate ◽  
Nitric Oxide Signaling ◽  
Minor Alleles ◽  
Oxide Synthase ◽  
Trigeminal Reflex ◽  
Inducible Nos ◽  
Nos Gene

Cluster headache is characterized by activation of the autonomic-trigeminal reflex. Nitric oxide can trigger headaches in patients, and nitric oxide signaling is known to be affected in cluster headache. Based on the hypothesis of nitric oxide being involved in cluster headache pathophysiology we investigated nitric oxide synthases as potential candidate genes for cluster headache. We analyzed eight variants in the three forms of nitric oxide synthase (NOS) genes, inducible NOS (iNOS), endothelial NOS (eNOS) and neuronal NOS (nNOS), and tested for association with cluster headache. Swedish cluster headache patients (n = 542) and controls (n = 581) were genotyped using TaqMan® assays on an Applied Biosystems 7500 qPCR cycler. This is the largest performed genetic study on NOS involvement in cluster headache so far. We found an association between cluster headache and one iNOS haplotype consisting of the minor alleles of rs2297518 and rs2779249 (p = 0.022). In addition, one of the analyzed nNOS variants, rs2682826, was associated with reported triptan use (p = 0.039). Our data suggest that genetic variants in NOS genes do not have a strong influence on cluster headache pathophysiology, but that certain combinations of genetic variants in NOS genes may influence the risk of developing the disorder or triptan use.

scholarly journals Threshold of permanent cornea thermal damage due to incidental continuous wave CO2 laser irradiation

2010 ◽  
Vol 14 (2) ◽  
pp. 459-467 ◽  
Author(s):  
Mayada Tahir
Keyword(s):  
Laser Irradiation ◽  
Co2 Laser ◽  
Thermal Damage ◽  
Continuous Wave ◽  
Anterior Part ◽  
Outer Part ◽  
Human Cornea ◽  
Thermal Dose ◽  
Element Analysis ◽  
Reflex Blink

Cornea thermal damage due to incidental continuous wave CO2 laser irradiation is studied numerically based on bio-heat equation. The interaction of laser with tissue leads to a rapid temperature increased in target and the nearby tissue. As the temperature of the eye surface reaches 44?C, a sensation of pain will cause aversion response of the reflex blink and/or shifting away from the source of pain. The aim of the work is to predict numerically the threshold limit of incidental laser power that causes damage to the anterior part of the cornea, which can be healed within 2-5 days as long as damage is not exceeding the outer part of the eye (epithelium). A finite element analysis is used to predict temperature distribution through the cornea where the necroses region can be obtained using thermal dose equation. The thermal dose that required for damaging the cornea is predicted from previously published experimental data on rhesus monkeys and used later as a limit for shrinkage to human cornea. The result of this work is compared by international standard of safety and a good nearby result is obtained which verified the result of this work.

The Trigemino-Pupillary Response in Cluster Headache

Cephalalgia ◽  
1993 ◽  
Vol 13 (5) ◽  
pp. 338-342 ◽  
Author(s):  
Giuseppe Micieli ◽  
Cristina Tassorelli ◽  
Luigi Ruiz ◽  
Giorgio Sandrini ◽  
Giuseppe Nappi
Keyword(s):  
Cluster Headache ◽  
Pain Perception ◽  
Active Phase ◽  
Pupillary Response ◽  
Neural Systems ◽  
Episodic Cluster Headache ◽  
Corneal Reflex ◽  
Remission Phase ◽  
Electrical Stimuli ◽  
Trigeminal Reflex

Central impairment of the integrative neural systems controlling vegetative function and pain perception has been demonstrated in cluster headache (CH). Recently, we described the human pupillary response (trigeminal reflex) to quantified (painless and painful) corneal stimulation with a combined neurophysiological and pharmacological technique. In this study, the trigeminal reflex was evaluated in 26 subjects with episodic cluster headache. During the active phase of the disease, on the side of the pain we observed reduced mydriasis to electrical stimuli with an intensity equal to the corneal reflex threshold, and on both sides to stimuli with intensity that equalled the pain threshold. No difference was found when amplitude of the miotic phase was compared in the different groups. These suggest disordered pupillary activation in response to pain, probably sympathetic in origin, which is bilateral, detectable also during the remission phase and which cannot be explained simply by the antidromic release of pain-related peptides.

scholarly journals Cerebellar Modulation of Trigeminal Reflex Blinks: Interpositus Neurons

2006 ◽  
Vol 26 (41) ◽  
pp. 10569-10576 ◽  
Author(s):  
F.-P. Chen ◽  
C. Evinger
Keyword(s):  
Reflex Blinks ◽  
Trigeminal Reflex

Telemetric Monitoring of the Reflex Blink Rate

1968 ◽  
Vol 26 (1) ◽  
pp. 303-307 ◽  
Author(s):  
Barbara L. Drinkwater ◽  
M. Marilyn Flint
Keyword(s):  
Action Potentials ◽  
Blink Rate ◽  
Muscle Action ◽  
Facial Movements ◽  
Reflex Blink ◽  
Reliability Coefficients

A technique for using telemetry to transmit the muscle action potentials of the eyeblink to a biological recorder is described in detail. Samples of oscillograph recordings are included to illustrate the patterns obtained from a variety of facial movements. Considering the high objectivity and reliability coefficients obtained, this procedure is recommended to those interested in using the blink rate as an experimental variable.

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