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Phrenic motoneuron morphology in the neonatal rat.
Phrenic motoneuron morphology in the neonatal rat.
- Source :
-
The Journal of comparative neurology [J Comp Neurol] 1991 Jun 08; Vol. 308 (2), pp. 169-79. - Publication Year :
- 1991
-
Abstract
- The morphology of neonatal rat phrenic motoneurons was studied following retrograde labeling with horseradish peroxidase, which resulted in Golgi-like fills of phrenic motoneuron somata and dendrites. At birth, these neurons have well-developed dendritic trees with many characteristics described for phrenic motoneurons in the adult rat. The dendrites form tightly fasciculated bundles that emerge from the phrenic nucleus primarily along four axes: ventromedial, ventrolateral, dorsolateral, and rostral/caudal, with smaller and more variable projections directly lateral and ventral. Although sparse, some dendritic appendages were also present, and in a few animals, somata clustering was apparent. The most significant difference between adult and neonatal rat phrenic motoneurons is in the extent to which medially and laterally projecting dendrites extend beyond the borders of the ipsilateral gray matter. In the neonate, unlike the adult, these dendrites project extensively past the gray/white border to the edge of the hemicord. Ventromedial dendrites occasionally cross to the contralateral ventral horn in the ventral white commissure and laterally projecting dendrites could be seen reaching the edge of the cord, turning and traveling rostrally or caudally for up to 100 microns. Phrenic motoneurons are not unique in having long dendrites at birth. A brief comparative study showed that neonatal cervical, thoracic, and lumbar motoneurons also have long dendrites that project to the medial and lateral borders of the hemicord.
- Subjects :
- Afferent Pathways anatomy & histology
Age Factors
Animals
Animals, Newborn anatomy & histology
Axonal Transport
Dendrites ultrastructure
Horseradish Peroxidase
Phrenic Nerve growth & development
Rats, Inbred Strains
Spinal Cord cytology
Spinal Cord growth & development
Motor Neurons ultrastructure
Phrenic Nerve cytology
Rats anatomy & histology
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9967
- Volume :
- 308
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- The Journal of comparative neurology
- Publication Type :
- Academic Journal
- Accession number :
- 1716267
- Full Text :
- https://doi.org/10.1002/cne.903080204