Changes in expression of peptides in rat facial motoneurons after facial nerve crushing and resection

Saika, Takanori; Senba, Emiko; Noguchi, Koichi; Sato, Makoto; Kubo, Takeshi; Matsunaga, Toru; Tohyama, Masaya

doi:10.1016/0169-328x(91)90027-u

Cited by 84 publications

(36 citation statements)

References 45 publications

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“…the GAL immunoreactivily is decreased in the internal zone and absent in the external zone. facial motoneurons after a lesion of the corresponding nerve [25,26]. Within the magnocellular perikarya, the increase in GAL immunoreactivity is already present 1 week after hypophysectomv, persists 2 weeks later and disappears 6 weeks after the hypophysectomv.…”

Section: Discussionmentioning

confidence: 95%

Effects of Hypophysectomy on Galaninergic Neurons in the Rat Hypothalamus

et al. 1993

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To understand better the relationship between hypothalamic galaninergic neurons and the pituitary gland, we studied the effects of hypophysectomy on hypothalamic galanin (GAL) content and distribution by radioimmunoassay and immunohistochemistry, and on GAL mRNA by Northern blot analysis. Three weeks after hypophysectomy, performed at 5 or 8 weeks of age, the hypothalamic concentrations of GAL and GAL mRNA were reduced by 30-50% in both male and female rats, compared to age- and sex-matched controls. Similar reverse-phase HPLC retention times of hypothalamic GAL were observed in intact and hypophysectomized rats. The reduction of hypothalamic GAL concentration following hypophysectomy was time-dependent, as peptide levels were unaffected one week after surgery. Immunohistochemistry showed regional differences in the effect of hypophysectomy on galaninergic neurons. In the hypophysiotropic hypothalamus, the scarce GAL immunoreactivity normally observed in the arcuate nuclei was no longer detectable in hypophysectomized rats, and the intense GAL immunoreactivity of the external zone of the median eminence progressively decreased and completely disappeared 3 and 6 weeks after hypophysectomy. In contrast, in the neurohypophyseal system, there was an increase of GAL labelling of the perikarya and emerging axons in the supraoptic and lateral-paraventricular nuclei, 1 and 3 weeks after hypophysectomy, that disappeared 6 weeks after hypophysectomy. An increase of GAL immunoreactivity was also observed in the internal zone of the median eminence 1 week but not 3 weeks after hypophysectomy. We conclude that hypophysectomy reduces the content of GAL and GAL mRNA in the rat hypothalamus. These changes are time-dependent and clearly detected after 3 weeks. The neurohypophyseal and hypophysiotropic galaninergic systems respond differently to hypophysectomy. In the neurohypophyseal system, the transient increase of GAL immunoreactivity could be related to axonal injury, diabetes insipidus or decreased neurosecretion. In contrast, the marked decrease of the GAL immunoreactivity found in the hypophysiotropic system, mainly in the external zone of the median eminence, accounts for the overall changes in hypothalamic peptide content and likely results from the loss of feedback up-regulation by pituitary or pituitary-dependent factors.

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Section: Discussionmentioning

confidence: 95%

Effects of Hypophysectomy on Galaninergic Neurons in the Rat Hypothalamus

et al. 1993

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“…Previous studies, on cranial and spinal motoneurons have determined how cellular levels of either ChAT (Lams et al, 1988;Armstrong et aI., 1991) or CGRP (Streit et al, 1989;Arvidsson et al, 1990;Haas et al, 1990;Dumoulin et al, 1991;Piehl et al, 1991;Saika et al, 1991) are affected by peripheral axotomy. This study is the first to quantify immunoreactive changes in proteins in the hypoglossal nucleus after different types of nerve injury and to compare enzyme and neuropeptide levels to the extent of peripheral reinnervation.…”

Section: Discussionmentioning

confidence: 99%

“…Recent molecular studies (Dumoulin et al, 1991) and in situ hybridation histochemistry (Haas et aI., 1990;Saika et al, 1991) point out that the increased levels of CGRP are associated with altered gene expression. Preliminary data in our laboratory are consistent with increased expression of o~CGRP mRNA, as has been reported in the facial nucleus (Saika et al, 1991) and anterior horn of the spinal cord (Noguchi et al, 1990).…”

Section: Cgrp Response To Hypoglossal Nerve Injurymentioning

confidence: 99%

“…As a putative trophic factor, CGRP appears in late prenatal development, increases rapidly, then decreases to adult levels of reduced immunoreactivity by the end of the fourth postnatal week (Kubota et al, 1988). Immunocytochemical and biochemical data have demonstrated an increase of CGRP after axotomy of cranial (Streit et al, 1989;Haas et al, 1990;Dumoulin et al, 1991;Saika et al, 1991) and spinal (Arvidsson et al, 1990;Noguchi et al, 1990;Piehl et al, 1991) motoneurons. In contrast to these findings, decreased acetylcholine (ACh) content in the axotomized neuron has been inferred from sharp decreases in choline acetyltransferase (CHAT), the enzyme that catalyzes ACh synthesis (Lares et al, 1988;Armstrong et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

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Choline acetyltransferase and calcitonin gene-related peptide immunoreactivity in motoneurons after different types of nerve injury

1993

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This study examined changes in choline acetyltransferase and calcitonin gene-related peptide immunoreactivity in hypoglossal motoneurons of rats at 1, 3, 7, 20 and 50 days after three types of nerve injury: crush, transection and resection. Peripheral reinnervation was assayed by retrograde labelling of the motoneurons after injections of the exogenous protein, horseradish peroxidase, into the tongue. Maximal reduction in choline acetyltransferase immunostaining occurred at seven days after nerve damage and the amount of the decrease was related to the nature of the injury. The recovery of choline acetyltransferase to normal levels was related to the timing of reinnervation after nerve crush, but not after transection or resection injuries. In contrast to these findings, a rapid increase in calcitonin gene-related peptide immunoreactivity preceded the decrease in choline acetyltransferase levels. A striking increase in calcitonin gene-related peptide immunoreactivity was observed at one day postoperative and was maximal at three days postoperatively for all injuries. Later changes in calcitonin gene-related peptide levels were dependent on the type injury. Increased calcitonin gene-related peptide staining persisted to 20 days after nerve crush. After nerve transection or resection, calcitonin gene-related peptide immunoreactivity decreased to basal levels at seven days postoperatively. This declination was followed by a second rise in calcitonin gene-related peptide immunolabeling at 20 days for nerve transection or 50 days after resection. Nearly complete reinnervation was established by 20 days after nerve crush. At 50 days after transection, less than half the number of normally-labelled neurons contained horseradish peroxidase. At this time only 1% of those whose axons had been resected were labelled. These observations suggest that different mechanisms regulate the responses of choline acetyltransferase and calcitonin gene-related peptide to nerve injury. The present results indicate that choline acetyltransferase levels in motoneurons can not be used to predict either the likelihood of or the timing of reinnervation after nerve transection or resection. However, our results strengthen the premise that an increased of calcitonin gene-related peptide immunoreactivity serves as a reliable index for predicting nerve regeneration/reinnervation after cranial nerve injury.

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“…This is why we chose the resection of an 8-to 10-mm length from all peripheral branches of the facial nerve as a lesion model. Earlier studies have shown that resection of a peripheral nerve in rats inhibits axonal resprouting (Angelov et al, 1993) and causes a slowly occurring death of the axotomized motoneurons (Saika et al, 1991), which is not accompanied by a breakdown of the blood-brain barrier (Shelper and Adrian, 1980).…”

Section: The Lesion Modelmentioning

confidence: 98%