title: Effect of cannabinoid receptor activation on spreading depression.
abstract: OBJECTIVE
  The objective of this study was to evaluate the effect of cannabinoid on cortical spreading depression (CSD) in rat brain. Cannabis has been used for centuries for both symptomatic and prophylactic treatment of different types of headaches including migraine. CSD is believed to be a putative neuronal mechanism underlying migraine aura and subsequent pain.
  
  
  METHODS
  The effects of Delta9-tetrahydrocannabinol (THC), as well as, cannabinoid CB1 and CB2 receptor agonists on CSD in rat neocortical slices were investigated. Furthermore, the effect of cannabinoid CB1 agonist was tested on field excitatory postsynaptic potentials (fEPSP) and long-term potentiation (LTP).
  
  
  RESULTS
  HC (1-20 microM) dose dependently suppressed CSD amplitude, duration, and propagation velocity. Cannabinoid CB1 agonist, WIN 55,212-2 mesylate (1-10 microM), also significantly suppressed all characteristic features of CSD. However, cannabinoid CB2 agonist, JWH-133 (1-20 microM), did not affect CSD. FEPSP and induction of LTP were suppressed by application of WIN55212-2.
  
  
  CONCLUSIONS
  Suppression of CSD by activation of CB1 receptors points to the potential therapeutic effects of cannabinoids in migraine with aura. More research is needed before we know whether cannabinoids may be helpful in treating migraine pain.
authors.affiliation: Shefa Neuroscience Research Centre, Tehran, Iran ; Department of Pediatrics, Shahed University, Tehran, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Kazemi
authors.forename: Mehdi
authors.initials: M
authors.lastname: Rahgozar
authors.forename: Erwin-Josef
authors.initials: EJ
authors.lastname: Speckmann
authors.forename: Ali
authors.initials: A
authors.lastname: Gorji
keywords: Endocannabinoid; Headache; Marijuana; Migraine; Pharmacotherapy; Synaptic transmission