title: An approach to localizing corneal pain representation in human primary somatosensory cortex.
abstract: The cornea has been a focus of animal electrophysiological research for decades, but little is known regarding its cortical representation in the human brain. This study attempts to localize the somatotopic representation of the cornea to painful stimuli in human primary somatosensory cortex using functional magnetic resonance imaging (fMRI). In this case study, a subject was imaged at 3T while bright light was presented in a block-design, which either produced pain and blinking (during photophobia) or blinking alone (after recovery from photophobia). Pain and blinking produced precisely localized activations in primary somatosensory cortex and primary motor cortex. These results indicate that noxious stimulation of the cornea can produce somatotopic activation in primary somatosensory cortex. This finding opens future avenues of research to evaluate the relationship between corneal pain and central brain mechanisms relating to the development of chronic pain conditions, such as dry eye-like symptoms.
authors.affiliation: P.A.I.N. Group, Center for Pain and the Brain, Children's Hospital Boston, Massachusetts General Hospital, Boston, Massachusetts, United States of America. eric.moulton@childrens.harvard.edu
authors.forename: Eric A
authors.initials: EA
authors.lastname: Moulton
authors.forename: Lino
authors.initials: L
authors.lastname: Becerra
authors.forename: Perry
authors.initials: P
authors.lastname: Rosenthal
authors.forename: David
authors.initials: D
authors.lastname: Borsook
mesh_terms: D001931:Brain Mapping / Q000379:methods; D003315:Cornea / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D058748:Pain Perception / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*