A Study of Overlap and Collateralization of Bulbar Reticular and Raphe Neurons which Project to the Spinal Cord and Diencephalon of the North American Opossum
- 1 January 1984
- journal article
- research article
- Published by S. Karger AG in Brain, Behavior and Evolution
- Vol. 24 (2-3) , 109-123
- https://doi.org/10.1159/000121309
Abstract
Labeled neurons were found in most reticular and raphe nuclei of the opossum''s medulla after horseradish peroxidase (HRP) injections into either the spinal cord or diencephalon. The labeling produced by spinal injections differed somewhat from that produced by diencephalic ones, but HRP-positive neurons were found in what appeared to be comparable areas. In order to study the intermingling of bulbospinal and bulbodiencephalic neurons more directly, we used fluorescent markers (true blue, nuclear yellow and diamidino yellow dihydrochloride) in double-labeling experiments. When injections of one dye into the spinal cord were combined with injections of another into the diencephalon, neurons labeled by one or the other marker were found to be intermingled in most reticular and raphe nuclei. The double-labeling experiments also showed that some neurons of the bulbar reticular formation and raphe project to both the spinal cord and diencephalon, presumably by axonal collaterals. The number of such neurons represents a somewhat larger proportion of those projecting to the diencephalon than to the spinal cord. It appears, however, that most neurons project either to the spinal cord or to the diencephalon and do not provide collaterals to both areas.Keywords
This publication has 18 references indexed in Scilit:
- Evidence for collateral innervation of the cervical and lumbar enlargements of the spinal cord by single reticular and raphe neurons. Studies using fluorescent markers in double-labeling experiments on the North American opossumNeuroscience Letters, 1981
- Growth and Reshaping of Axons in the Establishment of Visual Callosal ConnectionsScience, 1981
- Spinal projections from the medullary reticular formation of the North American opossum: Evidence for connectional heterogeneityJournal of Comparative Neurology, 1981
- Quantitative differences in collateralization of the descending spinal pathways from red nucleus and other brain stem cell groups in rat as demonstrated with the multiple fluorescent retrograde tracer techniqueBrain Research, 1981
- Descending projections from brainstem and sensorimotor cortex to spinal enlargements in the catExperimental Brain Research, 1981
- Ascending components of the medial forebrain bundle from the lower brain stem in the rat, with special reference to raphe and catecholamine cell groups. A study by the HRP methodBrain Research, 1980
- Observations on the development of brainstem-spinal systems in the north american opossumJournal of Comparative Neurology, 1978
- The organization of monoamine neurons within the brainstem of the north american opossum (didelphis virginiana)Journal of Comparative Neurology, 1978
- Afferent fiber connections from lower brain stem to hypothalamus studied by the horseradish peroxidase method with special reference to noradrenaline innervationExperimental Brain Research, 1978
- The blue reaction product in horseradish peroxidase neurohistochemistry: incubation parameters and visibility.Journal of Histochemistry & Cytochemistry, 1976