ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: The ability of neurotoxic substances to induce selective lesions of the descending monoaminergic pathways in rats was investigated. Saline, 6-hydroxydopamine, 5,6-dihydroxytryptamine, or 5,7-dihydroxytryp tamine were administered into the lumbar subarachnoid space through a chronically indwelling catheter. The lesions were evaluated 2–3 weeks later by in vitro uptake of [3H]noradrenaline and [14C]5-hydroxytryptamine into synaptosomal preparations from the frontal cortex, brain stem, cervical spinal cord, and lumbar spinal cord of each animal. There was no difference in uptake between saline-injected and noncatheterized controls and no significant changes in cortcial uptake after any of the treatments (dose range of neurotoxins: 0.6–80 μg). In the lumbar spinal cord, 6-hydroxydopamine (5–80 μg) reduced the [3H]noradrenaline uptake by approximately 90% with no effects on [14C]5-hydroxytryptamine uptake, whereas 5,6-dihydroxytryptamine reduced the uptake of [14C]5-hydroxytryptamine by 90% (20–80 μg). [3H]Noradrenaline uptake was unaffected by lower doses of 5,6-dihydroxy tryptamine but fell by 45–55% after 40–80 μg. 5,7-Dihydroxytryptamine (10–80 μg) reduced [3H]noradrenaline uptake by 90–95% and [14C]5-hydroxytryptamine uptake by approximately 80% (5–80 μg) in the lumbar cord. It is concluded that intrathecal administration of suitable doses of neurotoxins may produce extensive selective lesions of descending noradrenergic and serotonergic path ways.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1985.tb08738.x
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