Convergence of meningeal and facial afferents onto trigeminal brainstem neurons: an electrophysiological study in rat and man
- PMID: 10488673
- DOI: 10.1016/S0304-3959(99)00063-9
Convergence of meningeal and facial afferents onto trigeminal brainstem neurons: an electrophysiological study in rat and man
Abstract
Headache is often accompanied by referred pain in the face. This phenomenon is probably due to a convergence of afferent inputs from the meninges and the face onto central trigeminal neurons within the medullary dorsal horn (MDH). The possible existence and extent of this convergence was examined in rat and man. MDH neurons activated by stimulation of the parietal meninges were tested for convergent tactile and noxious mechanical input from all three facial branches of the trigeminal nerve. All 21 units with meningeal input could also be activated by facial stimuli. Brush stimuli applied to the supraorbital nerve area activated 86%, to the infraorbital nerve area 29%, and to the mental nerve area none of the units. Pinch stimuli applied to the supraorbital nerve area activated 95%, to the infraorbital nerve area 86%, and to the mental nerve area 52% of the units. The results suggest convergence of meningeal and facial inputs concentrated on the supraorbital nerve in rat. In man convergence was examined by probing neuronal excitability of MDH applying the blink reflex (BR) during Valsalva maneuver which probably increases intracranial pressure. The BR evoked by supraorbital nerve stimulation remained unchanged, while the BR evoked by mental nerve stimulation was significantly facilitated. This facilitation may be due to convergence of meningeal and facial inputs onto trigeminal neurons in man.
References
-
- Adriaensen H, Gybels J, Handwerker HO, van Hees J. Latencies of chemically evoked discharges in human cutaneous nociceptors and of the concurrent subjective sensations. Neurosci Lett. 1980;20:55-59.
-
- Apkarian AV, Jyvasjarvi E, Kniffki KD, Mengel MK, Stiefenhofer A. Activation of carotid sinus baroreceptors reduces pain sensations evoked by electrical and cold stimulation of human teeth. Proc Finn Dent Soc. 1989;85:409-413.
-
- Bouhassira D, Le Bars D, Villanueva L. Heterotopic activation of Ad and C fibres triggers inhibition of trigeminal and spinal convergent neurones in the rat. J Physiol. 1987;389:301-317.
-
- Burstein R, Yamamura H, Malick A, Strassman AM. Chemical stimulation of the intracranial dura induces enhanced responses to facial stimulation in brain stem trigeminal neurons. J Neurophysiol. 1998;79:964-982.
-
- Dahl JB, Erichsen CJ, Fuglsang-Frederiksen A, Kehlet H. Pain sensation and nociceptive reflex excitability in surgical patients and human volunteers. Br J Anaesth. 1992;69:117-121.
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