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Specific temporal and spatial distribution of JUN, FOS, and KROX‐24 proteins in spinal neurons following noxious transsynaptic stimulation
Author(s) -
Herdegen Thomas,
Kovary Karla,
Leah John,
Bravo Rodrigo
Publication year - 1991
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.903130113
Subject(s) - spinal cord , stimulation , biology , sciatic nerve , c jun , c fos , immediate early gene , immunocytochemistry , anatomy , noxious stimulus , nociception , basal (medicine) , french horn , neuroscience , endocrinology , gene expression , transcription factor , gene , receptor , insulin , psychology , pedagogy , biochemistry
We present the first comparative investigation of the basal and transsynaptically induced expression of c‐JUN, JUN B, JUN D, c‐FOS, FOS B, and KROX‐24 proteins in the spinal cord, using immunocytochemistry with specific antibodies. We demonstrate that electrical stimulation of the sciatic nerve at Aδ/C‐fiber (not Aα/β‐fiber) intensity strongly induces the expression of these immediate‐early gene‐encoded proteins. Basal immunoreactivity was found for c‐JUN in motoneurons, for JUN D in almost every cell of the gray matter, and for KROX‐24 in the superficial dorsal horn. One hour after electrical stimulation of the sciatic nerve at Aδ/C‐fiber intensity, expression of all proteins except JUN D reached its maximum. Initially immunoreactivity was restricted to the ipsilateral dorsal horn, but after 4 hours appeared contralaterally. Expression of JUN D was increased only after 4 hours. Within the dorsal horn, the expression of c‐JUN, JUN B, FOS B, and KROX‐24 was mainly restricted to the superficial layers. Immunoreactivity decreased to basal levels between 8 and 16 hours. c‐FOS and JUN D were expressed in both the superficial and deep dorsal horn; in the latter, c‐FOS and JUN D persisted longer. Induced JUN D was present the longest and was still visible after 32 hours. In motoneurons of the ipsilateral ventral horn, c‐JUN, JUN D, and c‐FOS appeared after 8 hours. Surgical exposure of the sciatic nerve evoked a strikingly prolonged expression of all proteins compared to that following electrical stimulation of the sciatic nerve. Our results demonstrate that stimulation of nociceptive Aδ‐ and C‐fibers induces early and late expression of proteins encoded by immediate‐early genes with a specific temporal and spatial distribution of the expression of each protein. Furthermore, the extent of protein expression reflects the intensity of noxious stimulation.