I have previously identified the central and peripheral components of a parasympathetic neural circuit in birds that may be involved in the light-regulated control of blood flow in the choroid of the eye. This circuit consists of: retina - supra-chiasmatic nucleus (SCN) - medial subdivision of the nucleus of Edinger-Westphal (EWM) - choroidal neurons of the ciliary ganglion - choroidal blood vessels. The proposed studies will explore the role of this circuit in the visually-mediated control of choroidal blood flow and the functional significance of such control. Using laser Doppler velocimetry to monitor choroidal blood flow, I will examine: 1) the effect of activation of the central components of this circuit on choroidal blood flow; and 2) the possibility that light-elicited alterations in choroidal blood flow are mediated via this circuit. To explore the importance of this circuit for the health of retinal photoreceptors, I will examine the effects of SCN lesions on photoreceptor viability under different illumination and temperature conditions. Additional neural circuits also appear to be involved in the control of choroidal blood flow. To elucidate these circuits, retrograde and anterograde pathway tracing techniques will be used to: 1) identify the other regions of the central nervous system that give rise to input to EWM and may thereby influence choroidal blood flow; and 2) detail the central components of the other neural circuits that innervate choroidal blood vessels, including a sympathetic adrenergic input and a VIP-containing parasympathetic input from the sphenopalatine ganglion. These studies will provide the basis for future work directed at elucidating the role and importance of these circuits for the health of the retina. Since the choroid plays a vital role in the sustenance of the retina, neural control of the choroid may have an important influence on retinal functions. Disruption of this control may result in abnormal regulation of blood flow and disturbances in retinal function, possibly leading to a heightened susceptibility of retinal photoreceptors to the deleterious effects of light and eventually to photoreceptor degeneration. Since defective neural control of choroidal blood flow may underlie some of the degenerative diseases of human photoreceptors, further understanding of the neural control of the choroid may lead to better treatments for these diseases.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY005298-05
Application #
3260302
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1984-12-01
Project End
1992-11-30
Budget Start
1987-12-01
Budget End
1988-11-30
Support Year
5
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Tennessee Health Science Center
Department
Type
Schools of Medicine
DUNS #
941884009
City
Memphis
State
TN
Country
United States
Zip Code
38163
Reiner, Anton; Fitzgerald, Malinda E C; Del Mar, Nobel et al. (2018) Neural control of choroidal blood flow. Prog Retin Eye Res 64:96-130
Li, Chunyan; Fitzgerald, Malinda E C; Del Mar, Nobel et al. (2018) Defective Choroidal Blood Flow Baroregulation and Retinal Dysfunction and Pathology Following Sympathetic Denervation of Choroid. Invest Ophthalmol Vis Sci 59:5032-5044
Li, Chunyan; Fitzgerald, Malinda E C; Del Mar, Nobel et al. (2016) Disinhibition of neurons of the nucleus of solitary tract that project to the superior salivatory nucleus causes choroidal vasodilation: Implications for mechanisms underlying choroidal baroregulation. Neurosci Lett 633:106-111
Li, Chunyan; Fitzgerald, Malinda E C; Del Mar, Nobel et al. (2015) The identification and neurochemical characterization of central neurons that target parasympathetic preganglionic neurons involved in the regulation of choroidal blood flow in the rat eye using pseudorabies virus, immunolabeling and conventional pathway Front Neuroanat 9:65
Reiner, Anton; Heldt, Scott A; Presley, Chaela S et al. (2015) Motor, visual and emotional deficits in mice after closed-head mild traumatic brain injury are alleviated by the novel CB2 inverse agonist SMM-189. Int J Mol Sci 16:758-87
Toledo, Claudio A B; Reiner, Anton; Patel, Reena S et al. (2011) Immunohistochemical localization of AMPA-type glutamate receptor subunits in the nucleus of the Edinger-Westphal in embryonic chick. Neurosci Lett 498:199-203
Reiner, Anton; Del Mar, Nobel; Zagvazdin, Yuri et al. (2011) Age-related impairment in choroidal blood flow compensation for arterial blood pressure fluctuation in pigeons. Invest Ophthalmol Vis Sci 52:7238-47
Kozicz, Tamás; Bittencourt, Jackson C; May, Paul J et al. (2011) The Edinger-Westphal nucleus: a historical, structural, and functional perspective on a dichotomous terminology. J Comp Neurol 519:1413-34
Reiner, Anton; Li, Chunyan; Del Mar, Nobel et al. (2010) Choroidal blood flow compensation in rats for arterial blood pressure decreases is neuronal nitric oxide-dependent but compensation for arterial blood pressure increases is not. Exp Eye Res 90:734-41
Li, Chunyan; Fitzgerald, Malinda E C; Ledoux, Mark S et al. (2010) Projections from the hypothalamic paraventricular nucleus and the nucleus of the solitary tract to prechoroidal neurons in the superior salivatory nucleus: Pathways controlling rodent choroidal blood flow. Brain Res 1358:123-39

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