z-logo
Premium
Spinal cord development in anuran larvae: I. Primary and secondary neurons
Author(s) -
Forehand Cynthia J.,
Farel Paul B.
Publication year - 1982
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.902090408
Subject(s) - biology , spinal cord , bullfrog , tadpole (physics) , metamorphosis , electrophysiology , neuroscience , brainstem , anatomy , rana , neuron , dorsal column nuclei , larva , endocrinology , physics , botany , particle physics
The spinal cord of the bullfrog (Rana catesbeiana) tadpole contains primary neurons, born during embryonic stages, and scondary neurons born for the most part during larval stages. Electrophysiological and anatomical characteristics of these two categories of neurons were examined during larval development to trace the development of secondary neurons and to determine whether primary neurons persist into adult life or are replaced by secondary neurons. Five classes of primary neuron were identified on the basis of their distinctive locations, morphologies, cytoplasmic melanin content, and presence at the earliest larval stages examined: primary motoneurons, Rohon‐Beard cells, commissural cells, dorsal marginal cells, and anterolateral marginal cells. Secondary neurons of the lateral motor column and dorsal root ganglia underwent extensive developmental changes during larval life manifested both in anatomical studies with horseradish peroxidase and electrophysiological experiments on the isolated spinal cord. Primary motoneurons that innervate the tadpole tail were not found in the adult, although those innervating thoracic musculature persisted, as did at least some primary neurons projecting to other spinal segments or brainstem. Primary neurons are thus replaced or maintained through metamorphosis depending on their class and location.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here