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5‐HT 1A receptor localization on the axon hillock of cervical spinal motoneurons in primates
Author(s) -
Kheck N. M.,
Gan P. J.,
Azmitia E. C.
Publication year - 1995
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903550205
Subject(s) - biology , axon hillock , spinal cord , axon , neuroscience , soma , receptor , 5 ht receptor , anatomy , serotonin , biochemistry
Serotonin (5‐HT) has direct and specific effects on the activity of spinal cord motoneurons. The 5‐HT 1A receptor has been shown to mediate motoneuron responses in spinal reflex pathways using the highly selective 5‐HT 1A receptor agonist 8‐OH‐DPAT. We have developed an antipeptide antibody that recognizes a specific region (the second external loop) of the 5‐HT 1A receptor. This 5‐HT 1A receptor antibody labels populations of neurons and glia in the primate cervical spinal cord. The highest receptor density is present in the superficial lamina of the dorsal horn, around the central canal, and on the axon hillock of large ventral horn motoneurons. The cellular labeling pattern on motoneurons shows a single, densely stained, tapering process emanating from the perikaryon. A more diffuse label is also present throughout the soma. Dendritic labeling was not apparent. These results suggest that post‐synaptic 5‐HT 1A receptors may be involved in modulating spinal motoneuron activity at the key site of action potential initiation, the axon hillock.