title: Neural Correlates of the Antinociceptive Effects of Stimulating the Anterior Pretectal Nucleus in Rats.
abstract: Stimulation-evoked antinociception (SEA) from the anterior pretectal nucleus (APtN) activates mechanisms that descend to the spinal cord through the dorsolateral funiculus, but the encephalic route followed by the descending pathways from the APtN is not completely known. This study evaluated the changes in the SEA from the APtN in the Wistar rat tail-flick test after lidocaine-induced neural block or N-methyl-d-aspartate-induced neurotoxic lesion of the deep mesencephalic nucleus (DpMe), tegmental pedunculopontine nucleus (PPTg), or lateral paragigantocellular nucleus (LPGi). The SEA from the APtN was less intense after neural block of the contralateral DpMe or PPTg or the ipsilateral LPGi, but was not changed by the neural block of the ipsilateral DpMe or PPTg or the contralateral LPGi. Antinociception did not occur when APtN stimulation was carried out 5 minutes after lidocaine or 6 days after N-methyl-d-aspartate injections into the contralateral DpMe and the ipsilateral LPGi, or into the contralateral PPTg and the ipsilateral LPGi. We conclude that the SEA from the APtN activates 2 descending pain inhibitory pathways, one relaying in the ipsilateral LPGi and another relaying sequentially in the contralateral DpMe and PPTg.
  
  
  
  The antinociceptive effect of the APtN stimulation involves 2 descending pathways: one relaying in the ipsilateral LPGi and another descending contralaterally via relays in the DpMe and PPTg.
authors: Department of Neuroscience and Behavioral Science, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Institute of Neuroscience and Behavior-INeC, Ribeirão Preto, São Paulo, Brazil.
authors: Karina
authors: K
authors: Genaro
authors: Institute of Neuroscience and Behavior-INeC, Ribeirão Preto, São Paulo, Brazil; Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. Electronic address: wadprado@fmrp.usp.br.
authors: Wiliam A
authors: WA
authors: Prado
mesh_terms: D000700:Analgesics / Q000627:therapeutic use; D000818:Animals; D001931:Brain Mapping; D004558:Electric Stimulation / Q000379:methods*; D018690:Excitatory Amino Acid Agonists / Q000008:administration & dosage; D007839:Functional Laterality; D008297:Male; D008845:Microinjections; D016202:N-Methylaspartate / Q000008:administration & dosage; D010146:Pain / Q000188:drug therapy; D059408:Pain Management; D020649:Pulvinar / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000700:Analgesics; D018690:Excitatory Amino Acid Agonists; D016202:N-Methylaspartate
keywords: Pain; anterior pretectal nucleus; deep mesencephalic nucleus; lateral paragigantocellular nucleus; tegmental pedunculopontine nucleus