title: Different trigemino-vascular responsiveness between adolescent and adult rats in a migraine model.
abstract: BACKGROUND
  Pediatric migraine displays different clinical features from adult migraine. Because the trigemino-vascular system (TGVS) plays a pivotal role in migraine pathophysiology, this study compared TGVS responses in a migraine model induced by intracisternal (i.c.) instillation of capsaicin in adolescent and adult rats.
  
  
  METHODS
  TGVS responses measured included c-Fos-protein-expressing neurons in the trigeminal cervical complex (TCC), calcitonin gene-related peptide (CGRP) expression in the trigeminal ganglia (TG) and dura mater, and dural protein extravasation. The formulas for estimating total numbers of activated TCC neurons were established based on the c-Fos-positive neuronal numbers in three sample sections, +0.6, -1.2 and -9 mm and +0.6, -0.6 and -6 mm, from the obex in adult and adolescent rats, respectively.
  
  
  RESULTS
  After capsaicin instillation, adolescent rats had comparable TCC neurons activated as adult rats, but less TGVS peripheral responsiveness than adults, including CGRP immunoreactivity in the TG, and protein extravasation and CGRP depletion (inversely reflected by CGRP immunoreactivity) in the dura mater.
  
  
  CONCLUSIONS
  Age-dependent differences in TGVS responsiveness in the i.c. capsaicin-induced migraine model of rats are reminiscent of less severe migraine in pediatric patients. This finding may provide new insight into the pathophysiology of migraine and guide the development of new anti-migraine drugs for children.
authors: Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, No. 1 Jen-Ai Rd., Taipei 100, Taiwan.
authors: Pi-Chuan
authors: PC
authors: Fan
authors: Ping-Hung
authors: PH
authors: Kuo
authors: James W
authors: JW
authors: Hu
authors: Shu-Hui
authors: SH
authors: Chang
authors: Sung-Tsang
authors: ST
authors: Hsieh
authors: Lih-Chu
authors: LC
authors: Chiou
mesh_terms: D000367:Age Factors; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis / Q000096:biosynthesis; D002211:Capsaicin / Q000633:toxicity; D004195:Disease Models, Animal; D004388:Dura Mater / Q000098:blood supply / Q000378:metabolism; D007150:Immunohistochemistry; D007509:Irritants / Q000633:toxicity; D008297:Male; D008881:Migraine Disorders / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012668:Trigeminal Ganglion / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D007509:Irritants; D016760:Proto-Oncogene Proteins c-fos; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin