A method for drug infusion into the lateral median eminence and arcuate nucleus of sheep
| Autor: | Stephen T. Anderson, K Sawangjaroen, J. D. Curlewis |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
medicine.medical_specialty
Quinpirole Microinjections Dopamine Ovariectomy Radioimmunoassay Biology Dopamine agonist Gonadotropin-Releasing Hormone Stereotaxic Techniques chemistry.chemical_compound Arcuate nucleus Internal medicine medicine Animals Neurotransmitter Injections Intraventricular Sheep Histocytochemistry General Neuroscience Arcuate Nucleus of Hypothalamus Median Eminence Luteinizing Hormone Prolactin Endocrinology chemistry Hypothalamus Median eminence Pulsatile Flow Dopamine Agonists Female hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Journal of neuroscience methods. 71(2) |
| ISSN: | 0165-0270 |
| Popis: | The role of catecholamines in the control of the GnRH pulse generator is unclear as studies have relied on the use of peripheral or intracerebroventricular injections, which lack specificity in relation to the anatomical site of action. Direct brain site infusions have been used, however, these are limited by the ability to accurately target small brain regions. One such area of interest in the control of GnRH is the median eminence and arcuate nucleus within the medial basal hypothalamus. Here we describe a method of stereotaxically targeting this area in a large animal (sheep) and an infusion system to deliver drugs into unrestrained conscious animals. To test our technique we infused the dopamine agonist, quinpirole or vehicle into the medial basal hypothalamus of ovariectomised ewes. Quinpirole significantly suppressed LH pulsatility only in animals with injectors located close to the lateral median eminence. This in vivo result supports the hypothesis that dopamine inhibits GnRH secretion by presynaptic inhibition in the lateral median eminence. Also infusion of quinpirole into the medial basal hypothalamus suppressed prolactin secretion providing in vivo evidence that is consistent with the hypothesis that there are stimulatory autoreceptors on tubero-infundibular dopamine neurons. |
| Databáze: | OpenAIRE |
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