Neocortical spreading depression provokes the expression of c-fos protein-like immunoreactivity within trigeminal nucleus caudalis via trigeminovascular mechanisms

摘要: The effects of neocortical spreading depression (SD) on the expression immunoreactive c-fos protein were examined within superficial laminae trigeminal nucleus caudalis (TNC), a brainstem region processing nociceptive information. KCl was microinjected into left parietal cortex at 9 min intervals over 1 hr, and SD detected by shift in interstitial DC potential adjacent frontal cortex. stained cells lower upper cervical spinal cord counted both sides after tissues sectioned (50 microns) processed for protein-like immunoreactivity (LI) using rabbit polyclonal antiserum. C-fos protein-LI visualized ventrolateral TNC, chiefly I Ilo predominantly segment C1-2 (e.g., -1.5 to -4.5 mm from obex) ipsilaterally. significantly increased cell staining ipsilateral TNC. ratio left: right 1.32 +/- 0.13 M KCl, as compared 1.06 0.05 control animals receiving NaCl instead microinjections (p < 0.01). reduced an insignificant difference chronic surgical transection meningeal afferents recurrent (1.09 0.11). Pretreatment with intravenous sumatriptan, 5-HT1-like receptor agonist that selectively blocks C-fibers attenuates TNC noxious stimulation, also (1.10 0.09). Sumatriptan or afferents, however, did not reduce ability induce SD. On other hand, combined hyperoxia hypercapnia only number evoked SDs 6.3 1.0 2.5 1.2 0.15 microinjection, but 0.01) associated These data indicate multiple activate increase protein-LI, observed ipsilaterally, probably mediated SD-induced stimulation ipsilaterally projecting unmyelinated innervating meninges. If true, this is first report demonstrating neurophysiological events cerebral can regions involved information via trigeminovascular mechanisms.