1. Developmentally regulated expression of calcitonin gene-related peptide at mammalian neuromuscular junction
- Author
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Guido Francesco Fumagalli, Maurizio Vitadello, Michela Matteoli, M. Cimino, Carlo Sala, Bice Chini, and Sergio Balbi
- Subjects
medicine.medical_specialty ,Aging ,Aging, Animals, Calcitonin Gene-Related Peptide ,analysis/genetics, Fluorescent Antibody Technique, Gene Expression Regulation, Motor Neurons ,metabolism, Muscle Development, Muscles ,metabolism, Neuromuscular Junction ,metabolism, Rats, Rats ,Inbred Strains, Receptors ,Cholinergic ,analysis, Spinal Cord ,growth /&/ development/metabolism ,analysis ,Calcitonin Gene-Related Peptide ,Inbred Strains ,Neuromuscular Junction ,Motor nerve ,Fluorescent Antibody Technique ,analysis/genetics ,In situ hybridization ,Calcitonin gene-related peptide ,Biology ,Muscle Development ,Neuromuscular junction ,Lumbar enlargement ,Cellular and Molecular Neuroscience ,Internal medicine ,Receptors ,medicine ,Animals ,Receptors, Cholinergic ,Motor Neurons ,Muscles ,Rats, Inbred Strains ,General Medicine ,Spinal cord ,Rats ,Endocrinology ,medicine.anatomical_structure ,Gene Expression Regulation ,Spinal Cord ,Calcitonin ,metabolism - Abstract
Using indirect immunofluorescence techniques, we have found that calcitonin gene-related peptide-like immunoreactivity is present in the neuromuscular junctions of somatic muscles as well as in almost all motor neurons of the lumbar enlargement of 1-week-old rats. It gradually decreases in both motor neurons and motor nerve endings as the animal grows up and completely disappears from the neuromuscular junctions in adult rats, persisting only in the motor nerve endings on the intrafusal fibers. In situ hybridization experiments have shown that the down-regulation of calcitonin gene-related peptide-like immunoreactivity is strictly related to a reduction in CGRP mRNA levels in the spinal motor neurons. These results indicate that the expression of CGRP is developmentally regulated in spinal cord alpha motor neurons. They also suggest that the peptide may play an important role at the immature neuromuscular junction.
- Published
- 1990