DESCENDING PROJECTIONS FROM THE CAUDAL MEDULLA-OBLONGATA TO THE SUPERFICIAL OR DEEP DORSAL HORN OF THE RAT SPINAL-CORD

• Tipo: Artigo em Revista Científica Internacional
• Data: 1994

Autores

Isaura Tavares (Autor) FMUP; Deolinda Lima (Autor) FMUP

Revista

Título: Experimental Brain Research

Vol. 99

Páginas: 455-463

ISSN: 0014-4819

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 58 Citações

Scopus - 62 Citações

Outras Informações

ID Authenticus: P-001-JZY

Abstract (EN): The location of neurons in the caudal medulla oblongata that project to the superficial or deep dorsal horn was studied in the rat, by means of retrograde labelling from confined spinal injection sites. The tracer cholera toxin subunit B was injected into laminae I-III (fuve rats) or I-V (three rats) at C-4-7 spinal segments. Neurons projecting to the superficial dorsal horn were located in the dorsomedial part of the dorsal reticular nucleus ipsilaterally, the subnucleus commissuralis of the nucleus tractus solitarius bilaterally, and a region occupying the lateralmost part of the ventrolateral reticular formation between the lateral reticular nucleus and the caudal pole of the spinal trigeminal nucleus, pars caudalis, bilaterally. Neurons projecting to the deep dorsal horn, which were only labelled when laminae I-V were filled by the tracer, occurred in the dorsomedial and ventrolateral parts of the dorsal reticular nucleus and in the ventral reticular nucleus bilaterally. A few cells were located in the above described lateralmost portion of the ventrolateral reticular formation bilaterally and in the ventral portion of the ipsilateral cuneate nucleus. In the light of previous data demonstrating that dorsal horn neurons project to the dorsal reticular nucleus, the ventrolateral reticular formation, and the nucleus tractus solitarius, and that neurons in these three medullary regions are involved in pain inhibition at the spinal level, the descending projections demonstrated here suggest the occurrence of spine -medullary-spinal loops mediating the analgesic actions elicited in each nucleus upon the arrival of nociceptive input from the dorsal horn.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9