Back to Search
Start Over
The role of tonic preganglionic neuron firing in the turnover of the large dense-cored vesicle store in sympathetic preganglionic nerve terminals.
- Source :
-
Neuroscience [Neuroscience] 1994 Sep; Vol. 62 (2), pp. 531-8. - Publication Year :
- 1994
-
Abstract
- Large dense-cored vesicles are transported centrifugally in the cervical sympathetic trunk and are depleted in a calcium-dependent manner from synaptic boutons of the cat superior cervical ganglion during orthodromic stimulation at 20-40 Hz [P. Weldon et al. (1993) Neuroscience 55, 1045-1054]. In the present study, we tested in awake cats whether the normal tonic firing of the sympathetic preganglionic neuron contributes to the turnover of large dense-cored vesicles in synaptic boutons of the superior cervical ganglion. Tetrodotoxin was applied with a mini-osmotic pump to one cervical sympathetic trunk, while vehicle alone was applied to the contralateral cervical sympathetic trunk, for two, four or seven days. The appearance of Horner syndrome ipsilateral to the tetrodotoxin application demonstrated block of action potential propagation. Both superior cervical ganglia were excised and processed for electron microscopy. The number of large dense-cored vesicles per bouton cross-section was higher in the ganglion with tetrodotoxin-treated input than in the control. The content at four days was higher than at two days; the content at seven days was similar to that at four days. The number of lysosomes per bouton profile also increased in the ganglion with tetrodotoxin-treated input. No changes were observed in size of bouton profiles, number of boutons or of synapses per grid square and length of the presynaptic densities in the ganglion with tetrodotoxin-treated input.(ABSTRACT TRUNCATED AT 250 WORDS)
- Subjects :
- Animals
Axons drug effects
Axons physiology
Axons ultrastructure
Cats
Dendrites drug effects
Dendrites physiology
Dendrites ultrastructure
Electric Stimulation
Functional Laterality
Nerve Endings drug effects
Neurons drug effects
Reference Values
Superior Cervical Ganglion drug effects
Synapses drug effects
Synapses physiology
Synapses ultrastructure
Tetrodotoxin pharmacology
Time Factors
Nerve Endings physiology
Neurons physiology
Superior Cervical Ganglion physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0306-4522
- Volume :
- 62
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Neuroscience
- Publication Type :
- Academic Journal
- Accession number :
- 7830896
- Full Text :
- https://doi.org/10.1016/0306-4522(94)90386-7