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Lesion‐induced changes in the central terminal distribution of galanin‐immunoreactive axons in the dorsal column nuclei
Author(s) -
Hoeflinger Brian F.,
BennettClarke Carol A.,
Chiaia Nicolas L.,
Killackey Herbert P.,
Wall John T.,
Rhoades Robert W.
Publication year - 1993
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.903320309
Subject(s) - cuneate nucleus , galanin , forelimb , biology , brainstem , lesion , calcitonin gene related peptide , nucleus , dorsal column nuclei , anatomy , neuropeptide , brachial plexus , plexus , calcitonin , endocrinology , medicine , neuroscience , pathology , receptor , biochemistry
Rats that sustained forelimb removal on either embryonic day (E) 16, on the day of birth (P‐0), or transection of the brachial plexus in adulthood had brainstem sections stained for galanin, calcitonin gene‐related peptide (CGRP), or substance P (SP) at various intervals after these lesions were made. In normal adult rats, only a few galanin‐immunoreactive fibers are present in the cuneate nucleus and most are located in its caudal portion. CGRP‐positive axons are also sparse in the cuneate and are distributed mainly in the periphery of the nucleus. SP‐positive axons are seen throughout the cuneate nucleus. In rats that sustained forelimb removals at birth or transection of the brachial plexus in adulthood, dense galanin immunoreactivity was present throughout the cuneate nucleus at all rostrocaudal levels on the side of the brainstem ipsilateral to the lesion. The changes after lesions that were made in the adult animals were apparent within 1 week, the earliest time analyzed. Increases in galanin immunoreactivity in the cuneate of animals that sustained forelimb removals on P‐0 were first visible on P‐2. Neither forelimb removal at birth nor brachial plexus lesions in adulthood had any qualitative effect upon the distribution or density of CGRP‐ or SP‐immunoreactivity in the cuneate nucleus. Removal of a forelimb on E‐16 did not increase the density of galanin‐immunoreactive fibers in the cuneate nucleus. Such lesions also failed to produce any appreciable change in the density of either CGRP‐ or SP‐positive fibers in the cuneate nucleus. The present data raise the possibility that large caliber, non‐peptidergic primary afferent axons which innervate the cuneate nucleus may express galanin after damage at birth or in adulthood. © 1993 Wiley‐Liss, Inc.