title: Projection from excitatory C3-C4 propriospinal neurones to lamina VII and VIII neurones in the C6-Th1 segments of the cat.
abstract: Intracellular recording and injection of horseradish peroxidase (HRP) were made in neurones located medially in lamina VII and in lamina VIII of the forelimb segments (C6-Th1). The cells received disynaptic excitation from the contralateral pyramid after corticospinal transection in C5/C6 and monosynaptic excitation from the ipsilateral lateral reticular nucleus. The pyramidal excitation was facilitated by a conditioning volley evoked from the contralateral nucleus ruber, which suggests convergence of cortico- and rubrospinal fibres on the intercalated neurones. It is proposed that laminae VII and VIII neurones receive a collateral input from the same excitatory C3-C4 propriospinal neurones which project to motoneurones and/or Ia inhibitory interneurones. Reconstruction of HRP-stained lamina VII and VIII neurones revealed ipsi- and contralateral ascending and/or descending axonal projections and termination in laminae VII and VIII in the forelimb segments.
authors.affiliation: Department of Physiology, University of Göteborg, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Alstermark
authors.forename: T
authors.initials: T
authors.lastname: Isa
authors.forename: H
authors.initials: H
authors.lastname: Kümmel
authors.forename: B
authors.initials: B
authors.lastname: Tantisira
mesh_terms: D000758:Anesthesia; D000818:Animals; D001369:Axons / Q000648:ultrastructure; D002415:Cats; D006735:Horseradish Peroxidase; D009046:Motor Neurons / Q000648:ultrastructure; D009474:Neurons / Q000502:physiology*; D011712:Pyramidal Tracts / Q000166:cytology / Q000648:ultrastructure; D012154:Reticular Formation / Q000166:cytology / Q000187:drug effects; D013116:Spinal Cord / Q000166:cytology*
chemical_list: D006735:Horseradish Peroxidase