PURPOSE: The authors investigated whether trigeminal sensitization occurs in response to bright light with the retina disconnected from the rest of the central nervous system by optic nerve section. METHODS: In urethane-anesthetized rats, trigeminal reflex blinks were evoked with air puff stimuli directed at the cornea in darkness and at three different light intensities. After normative data were collected, the optic nerve was lesioned and the rats were retested. In an alert rat, reflex blinks were evoked by stimulation of the supraorbital branch of the trigeminal nerve in the dark and in the light. RESULTS: A 9.1 × 10(3) μW/cm(2) and a 15.1 × 10(3) μW/cm(2) light significantly enhanced the magnitude of reflex blinks relative to blinks evoked by the same trigeminal stimulus when the rats were in the dark. In addition, rats exhibited a significant increase in spontaneous blinking in the light relative to the blink rate in darkness. After lesioning of the optic nerve, the 15.1 × 10(3) μW/cm(2) light still significantly increased the magnitude of trigeminal reflex blinks. CONCLUSIONS: Bright lights increase trigeminal reflex blink amplitude and the rate of spontaneous blinking in rodents. Light can modify trigeminal activity without involving the central visual system.
PURPOSE: The authors investigated whether trigeminal sensitization occurs in response to bright light with the retina disconnected from the rest of the central nervous system by optic nerve section. METHODS: In urethane-anesthetized rats, trigeminal reflex blinks were evoked with air puff stimuli directed at the cornea in darkness and at three different light intensities. After normative data were collected, the optic nerve was lesioned and the rats were retested. In an alert rat, reflex blinks were evoked by stimulation of the supraorbital branch of the trigeminal nerve in the dark and in the light. RESULTS: A 9.1 × 10(3) μW/cm(2) and a 15.1 × 10(3) μW/cm(2) light significantly enhanced the magnitude of reflex blinks relative to blinks evoked by the same trigeminal stimulus when the rats were in the dark. In addition, rats exhibited a significant increase in spontaneous blinking in the light relative to the blink rate in darkness. After lesioning of the optic nerve, the 15.1 × 10(3) μW/cm(2) light still significantly increased the magnitude of trigeminal reflex blinks. CONCLUSIONS: Bright lights increase trigeminal reflex blink amplitude and the rate of spontaneous blinking in rodents. Light can modify trigeminal activity without involving the central visual system.
Authors: Shruti Aggarwal; Ahmad Kheirkhah; Bernardo M Cavalcanti; Andrea Cruzat; Clara Colon; Emma Brown; David Borsook; Harald Prüss; Pedram Hamrah Journal: Ocul Surf Date: 2015-02-20 Impact factor: 5.033
Authors: Adisa Kuburas; Stewart Thompson; Nikolai O Artemyev; Randy H Kardon; Andrew F Russo Journal: Invest Ophthalmol Vis Sci Date: 2014-09-25 Impact factor: 4.799
Authors: Anton Delwig; Shawnta Y Chaney; Andrea S Bertke; Jan Verweij; Susana Quirce; Delaine D Larsen; Cindy Yang; Ethan Buhr; Russell VAN Gelder; Juana Gallar; Todd Margolis; David R Copenhagen Journal: Vis Neurosci Date: 2018-01 Impact factor: 3.241