Journal of Neuroscience, Vol 6, 2200-2207, Copyright © 1986 by Society for Neuroscience
Pattern of intracranial and extracranial projections of trigeminal ganglion cells
TP O'Connor and D van der Kooy
The trigeminal sensory innervation of the major cerebral vessels is thought
to carry the nociceptive information during a migraine headache, and this
pain is usually referred to the forehead area. Using retrograde tracing
techniques, we have described the distribution of sensory trigeminal cells
that innervate the middle cerebral artery (MCA) and the forehead.
Nearest-neighbor analysis of the ophthalmic division of the trigeminal
ganglion revealed that cells innervating the forehead tend to be clumped
around individual cells that innervate the MCA. An average of less than 1
cell per animal was found to project divergent collaterals to both areas.
The close association of ganglion cell bodies innervating the cerebral
vasculature and those innervating forehead areas may underlie the
convergence of their central processes onto common brain-stem trigeminal
nucleus cells, and thus the referral of headache pain. In contrast to the
lack of ganglion cells with axonal collaterals to the cerebral vasculature
and forehead, a significant population of cells that innervate the MCA also
have collateral projections to other cerebral arterial branches (branches
of the middle meningeal artery), as well as the surrounding dura. Thus, the
innervation targets of individual trigeminal cells are very widespread
intracranially (including arteries and dura), but separate cells in the
ophthalmic division innervate extracranial targets.
Previous Article | Next Article
