In order to demonstrate the influence of morphine on the developmental localization of regenerated noradrenergic fibers in rat cerebellum, a glyoxylic histofluorescent method and radiometric assay for norepinephrine (NE) were utilized. An initial reduction of NE in the cerebellum after 6-hydroxydopa [6-OHDOPA; 60 µg/g intraperitoneally (i.p.)] was followed by a return to control levels at 3 days, and an elevation above control levels at 7 days. The initial rates of recovery of NE in the cerebellum of the 6-OHDOPA group of rats and the group receiving morphine (20 µg/g i.p.) in combination with 6-OHDOPA were identical up to 7 days. However, by 14 days NE content was further elevated in the cerebellum of the morphine+6-OHDOPA group. Histofluorescent microscopic observations of the cerebellar cortex correlated with the biochemical findings. A reduction in cerebellar NE content at 3 days was associated with a reduction in the number of visible histofluorescent fibers in the cerebellar cortex. By 7 days the relative number of fibers in the 6-OHDOPA groups was similar to that seen in the control group, but by 9 days the relative number of fluorescent fibers in the cerebellar cortex was increased above control. By 13 days there was a further increase in the relative number of fluorescent fibers in the cerebellar cortex of the morphine+6-OHDOPA group, as compared to the group treated with 6-OHDOPA alone. These findings provide an anatomic correlate for recovery of noradrenergic fibers after 6-OHDOPA, and demonstrate an action of morphine in enhancing regenerative sprouting.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-14536 |
| Date | 01 January 1982 |
| Creators | Harston, Craig T., Blair Clark, M., Hardin, Judy C., Kostrzewa, Richard M. |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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