title: [Endogenous cannabinoid system. Effect on neuronal plasticity and pain memory].
abstract: OBJECTIVE
  The aim of this study was to evaluate the role of the endogenous cannabinoid system in controlling neuroplasticity.
  
  
  METHODS
  The pain threshold for electrical stimuli was determined in transgenic mice lacking the cannabinoid receptor type 1 (CB1(-/-)) and in the corresponding respective wild-type animals. Electrophysiological experiments were performed in prepared brain slices to test the effect of endogenous and exogenous cannabinoids on synaptic transmission and long-term potentiation (LTP) in the amygdala.
  
  
  RESULTS
  The pain threshold was nearly identical in both groups for the first pain induction; however, with repeated pain induction it decreased to a significantly greater extent in the CB1(-/-) mice than in the wild-type animals. Synoptic transmission and the inducibility of LTP were not influenced by the acute pharmacological blockade of CB1 receptors, but inhibited by the CB1 agonist WIN55,212-2.
  
  
  CONCLUSIONS
  The endogenous cannabinoid system is involved in the control of neuroplasticity as part of pain processing . Cannabinoids prevent the formation of LTP in the amygdala via activation of CB1 receptors. Synoptic transmission and the inducibility of LTP were not influenced by the acute pharmacological blockade of CB1 receptors, but inhibited by the CB1 agonist Win55,212-2.
authors.affiliation: Abt. Klinische Neuropharmakologie, Max-Planck-Institut für Psychiatrie München. azad@mpipsykl.mpg.de
authors.forename: S C
authors.initials: SC
authors.lastname: Azad
authors.forename: V
authors.initials: V
authors.lastname: Huge
authors.forename: P
authors.initials: P
authors.lastname: Schöps
authors.forename: C
authors.initials: C
authors.lastname: Hilf
authors.forename: A
authors.initials: A
authors.lastname: Beyer
authors.forename: H-U
authors.initials: HU
authors.lastname: Dodt
authors.forename: G
authors.initials: G
authors.lastname: Rammes
authors.forename: W
authors.initials: W
authors.lastname: Zieglgänsberger
mesh_terms: D002186:Cannabinoids / Q000378:metabolism; D004558:Electric Stimulation; D004723:Endorphins / Q000502:physiology*; D006801:Humans; D008568:Memory; D009473:Neuronal Plasticity / Q000502:physiology*; D010146:Pain / Q000523:psychology*; D043882:Receptors, Cannabinoid / Q000502:physiology*
chemical_list: D002186:Cannabinoids; D004723:Endorphins; D043882:Receptors, Cannabinoid