title: Cytoarchitecture, morphology, and lumbosacral spinal cord projections of the red nucleus in cattle.
abstract: OBJECTIVE
  To analyze the morphology, cytoarchitecture, and lumbosacral spinal cord projections of the red nucleus (RN) in cattle.
  
  
  METHODS
  8 healthy Friesian male calves.
  
  
  METHODS
  Anesthetized calves underwent a dorsal laminectomy at L5. Eight bilateral injections (lateral to the midline) of the neuronal retrograde fluorescent tracer fast blue (FB) were administered into the exposed lumbosacral portion of the spinal cord. A postsurgical calf survival time of 38 to 55 days was used. Following euthanasia, the midbrain and the L5-S2 spinal cord segments were removed. Nissl's method of staining was applied on paraffin-embedded and frozen sections of the midbrain.
  
  
  RESULTS
  The mean length of the RN from the caudal to cranial end ranged from 6,680 to 8,640 microm. The magnocellular and parvicellular components of the RN were intermixed throughout the nucleus, but the former predominate at the caudal portion of the nucleus and the latter at the cranial portion with a gradual transitional zone. The FB-labeled neurons were found along the entire craniocaudal extension of the nucleus, mainly in its ventrolateral part. The number of FB-labeled neurons was determined in 4 calves, ranging from 191 to 1,469 (mean, 465). The mean cross-sectional area of the FB-labeled neurons was approximately 1,680 microm2.
  
  
  CONCLUSIONS
  In cattle, small, medium, and large RN neurons, located along the entire craniocaudal extension of the RN, contribute to the rubrospinal tract reaching the L6-S1 spinal cord segments. Thus, in cattle, as has been shown in cats, the RN parvicellular population also projects to the spinal cord.
authors.affiliation: Department of Veterinary Morphophysiology and Animal Productions, University of Bologna, 40064 Ozzano dell'Emilia, Bologna, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Chiocchetti
authors.forename: Cristiano
authors.initials: C
authors.lastname: Bombardi
authors.forename: Annamaria
authors.initials: A
authors.lastname: Grandis
authors.forename: Gemma
authors.initials: G
authors.lastname: Mazzuoli
authors.forename: Arcangelo
authors.initials: A
authors.lastname: Gentile
authors.forename: Luciano
authors.initials: L
authors.lastname: Pisoni
authors.forename: Monica
authors.initials: M
authors.lastname: Joechler
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Lucchi
mesh_terms: D000818:Animals; D002417:Cattle; D008297:Male; D012012:Red Nucleus / Q000166:cytology*; D013116:Spinal Cord / Q000033:anatomy & histology*