Pre- and post-junctional supersensitivity: Differentiation by intraventricular infusions of norepinephrine and methoxamine
✍ Scribed by David S. Segal; Mark A. Geyer
- Publisher
- Springer
- Year
- 1976
- Tongue
- English
- Weight
- 384 KB
- Volume
- 50
- Category
- Article
- ISSN
- 0033-3158
No coin nor oath required. For personal study only.
✦ Synopsis
Intraventricular infusions of methoxamine, an adrenergic agonist that has a relatively low affinity for the presynaptic uptake mechanism, produces a significant dose-dependent increase in locomotor activity comparable to the increase elicited by infusion of equimolar doses of norepinephrine (NE). The behavioral responsiveness to infusion of both NE and methoxamine was more than doubled 3 weeks after pretreatment with 6-hydroxydopamine (6-OHDA). These results indicate that the increased responsiveness to NE induced by 6-OHDA is due to enhanced postsynaptic receptor sensitivity rather than to a loss of presynaptic uptake inactivation.