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Paul J. May, PhD

Assistant Professor, Ophthalmology
Assistant Professor, Neurology
Associate Chair for Research, Neurobiology and Anatomical Sciences
Office: R720; (601) 984-1662
Lab: R717; (601) 984-2646
Fax: (601) 984-1655


  • AB - Brown University, Providence, R.I. 1976, Biology and English Literature
  • PhD - Duke University, Durham, N.C. 1983, Anatomy.
  • Postdoctoral Fellow - Department of Physiology & Biophysics, New York University Medical Center, New York, NY, 1983-86. 

Research interests

  • Trigeminal pathways
  • Circuitry of eyelid, pupil and lens reflexes
  • Proprioceptive control of eye movements
  • Visual gaze control

Research program

may---image-1.jpgThe general experimental theme of the laboratory is the study of gaze control utilizing anatomical and, in some cases, physiological methods. Dual input-output labeling techniques have been pioneered in this laboratory to support this investigation on the light and electron microscopic level. Students can take advantage of opportunities to learn: neuroanatomical tracer techniques, immunohistochemistry, sterile surgery, electron microscopy and post-embedding immunohistochemical localization. There are ongoing investigations in a number of areas concerning gaze control:

  • Control of movements of the eyes and head by the superior colliculus. Both the input-output relationships of superior colliculus and the relationship of collicular projections to cell populations in the horizontal and vertical gaze centers are being studied. The emphasis is on determining the morphology and laminar location of relevant collicular neurons and their synaptic relationships, both within the superior colliculus and between collicular axons and target neurons.
  • Neuronal circuitry controlling the lens and pupil is being investigated. Neuroanatomical tracers have been used to determine the circuits controlling the pupillary light reflex, and are being applied to identify the circuits controlling the near reflex components, i.e., ciliary muscle for lens accommodation, medial rectus muscle for vergence and sphincter pupillae muscle for pupillary constriction.
  • Determination of premotor circuitry underlying the blink reflex. The act of blinking is a simple reflex activity that has become important in various learning paradigms and has clinical relevance as well. However, the circuits that support this reflex are poorly understood. This investigation utilizes dual labeling of inputs and outputs to define blink circuits at the light and electron microscopic level.may---image-2.jpg

Current funding

  • NEI RO1 Grant (EY014263)
    Midbrain Circuitry for Neuronal Control of Gaze. Co-PI, 2015-19
  • NIDCD R01 Grant (DC014930)
    Neural Mechanisms of Active Gaze Stabilization (AGS) in Monkeys. Co-PI, 2015-19
  • NEI R01 Grant (R01EY019963)
    An In Vitro Model of Saccadic Eye Movement Choice. Co-I, 2016-21

Selected publications

* In last four years. A complete publication list can be accessed through MyBibliography at NCBI.
  • Barnerssoi, Miriam and Paul J. May. (2015) Postembedding Immunohistochemistry for Inhibitory Neurotransmitters in Conjunction with Neuroanatomical Tracers. In: Transmission Electron Microscopy Methods for Understanding the Brain, Edited by E.J. Van Boekstaele, Springer (In Press).

Peer-reviewed papers

  • May, Paul J, Susan Warren, Martin O. Bohlen, Miriam Barnerssoi, and Anja K.E. Horn, (2015) The central mesencephalic reticular formation projection to the Edinger-Westphal nucleus. Brain Structure and Function (Submitted).
  • Bohlen, Martin O., Susan Warren and Paul J. May. (2015) A central mesencephalic reticular formation projection to the supraoculomotor area in macaque monkeys. Brain Structure & Function (Currently an EPub).
  • Sun, Wensi and Paul J. May (2014) Central pupillary light reflex circuits in the cat: Morphology, ultrastructure and inputs of preganglionic motoneurons. Journal of Comparative Neurology 522: 3978-4002.
  • Sun, Wensi and Paul J. May (2014) Central pupillary light reflex circuits in the cat: The olivary pretectal nucleus. Journal of Comparative Neurology 522: 3960-77
Recent abstracts
  • Bohlen, M.O., S. Warren and P.J. May (2015) Central Mesencephalic Reticular Formation Projections to Horizontal Gaze Motoneurons - A Green Light or Red? Soc. Neurosci. Abst. 41
  • Barnerssoi, M., P.J. May, A.K.E. Horn (2014) GABAergic innervation of the monkey ciliary ganglion - An electron microscopy study. Soc. Neurosci. Abst. 40: 62.05.
  • Bohlen, M.O., S. Warren, R. Blumer, J.F. Stahl, P.J. May (2014) The organization of extraocular muscle motoneuronal pools in the mouse. Soc. Neurosci. Abst. 40: 62.12