trkC-like immunoreactivity in the primate descending serotoninergic system.
In the search for substances with a potential role in plastic responses of spinal motoneurons we have studied the distribution of trkC-like immunoreactivity in the spinal cord of adult monkeys (Macaca fascicularis). The presence of trkC, which is a signal-transducing receptor for neurotrophin-3, was detected by the use of indirect immunofluorescence with a rabbit polyclonal antibody raised against a synthetic peptide corresponding to the carboxy-terminal domain of the mouse trkC-encoded protein, thus detecting only full-length signal-transducing receptors. trkC-immunoreactive fibres/varicosities could be found at all spinal cord levels and the densest innervation was found in the autonomic intermediolateral and Onuf's nuclei, but somatic motoneuron pools also received a significant contribution of trkC-immunoreactive fibres. Terminals immunoreactive for trkC were also seen in the dorsal horn. Double-labelling experiments revealed a high degree of coexistence between trkC- and 5-hydroxytryptamine (serotonin)-like immunoreactivity in all areas except in the dorsal horn. The results of the present study suggest that neurotrophic signalling with an influence on serotoninergic as well as non-serotoninergic inputs to the adult monkey spinal cord is at hand.
Arvidsson
U
U
Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Risling
M
M
Frisén
J
J
Piehl
F
F
Fried
K
K
Hökfelt
T
T
Cullheim
S
S
D000818:Animals; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D008252:Macaca fascicularis; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism*; D009928:Organ Specificity; D011519:Proto-Oncogenes; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis* / Q000096:biosynthesis; D020812:Receptor, trkC; D017978:Receptors, Growth Factor / Q000032:analysis* / Q000096:biosynthesis; D012701:Serotonin / Q000378:metabolism*; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*
D008565:Membrane Proteins; D017978:Receptors, Growth Factor; D012701:Serotonin; D020794:Receptor Protein-Tyrosine Kinases; D020812:Receptor, trkC