title: Further studies on interactions between periaqueductal gray, nucleus accumbens and habenula in antinociception.
abstract: Previous findings from this laboratory with the intracerebral microinjection technique suggested that the periaqueductal gray (PAG), nucleus accumbens, and habenula might constitute a unidirectional loop to play their roles in pain modulation. In the present study we demonstrate that intra-habenular injection of naloxone antagonizes the analgesia elicited by morphine injected into the periaqueductal gray (PAG) and that intra-accumbens injection of naloxone is capable of attenuating the analgesic effects of morphine injected into the habenula. These results indicate that the relationships between these nuclei may be more complex than the putative unidirectional loop.
authors.affiliation: Department of Physiology, Beijing Medical University, China.
authors.forename: Q P
authors.initials: QP
authors.lastname: Ma
authors.forename: Y S
authors.initials: YS
authors.lastname: Shi
authors.forename: J S
authors.initials: JS
authors.lastname: Han
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004924:Escape Reaction / Q000187:drug effects*; D008297:Male; D008845:Microinjections; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D010487:Periaqueductal Gray / Q000187:drug effects / Q000502:physiology*; D011817:Rabbits; D013788:Thalamus / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
chemical_list: D009270:Naloxone; D009020:Morphine