The induction by testosterone of aromatase activity in the preoptic area and activation of copulatory behavior
| Autor: | J. C. Hendrick, Jacques Balthazart, Agnès Foidart |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Male
medicine.medical_specialty medicine.drug_class Experimental and Cognitive Psychology Coturnix Quail Behavioral Neuroscience Aromatase Cloaca Internal medicine biology.animal Copulation medicine Animals Testosterone Enzyme inducer Sex Characteristics Aromatase inhibitor biology Aromatase Inhibitors Androstatrienes Luteinizing Hormone biology.organism_classification Preoptic Area Preoptic area Endocrinology Enzyme Induction biology.protein Female Luteinizing hormone |
| Zdroj: | Physiology & Behavior. 47:83-94 |
| ISSN: | 0031-9384 |
| Popis: | A series of 4 experiments was designed to study the relationships between the activity of the aromatase (AA) in the preoptic area (POA) and the activation by testosterone (T) of copulatory behavior in gonadectomized male and female Japanese quail. The induction of AA by T in the POA is dose- and time-dependent. Levels of AA seen in sexually mature males are restored in castrated birds by a treatment with 20 to 40 mm silastic T capsules which produce physiological levels of steroid in the plasma. The minimal dose of T (10 mm implant) which reliably restores copulatory behavior approximately doubles the AA in the POA. The induction of AA is significantly larger in males than in females. A significant increase in AA is observed within 16 hours after the start of the treatment with T and the induction is maximal after 48 hours. Activation of copulatory behavior follows a similar time course but occurs with a delay of 24-48 hours. These results thus suggest that, in male quail, the activity of the aromatase in the POA is a limiting factor in the activation of copulatory behavior. This idea is confirmed by direct experimentation using an aromatase inhibitor, androstatrienedione (ATD). If T-treated birds receive at the same time silastic implants filled with ATD, the activation of behavior is suppressed for at least one week. This behavioral inhibition is, as expected, accompanied and very probably caused by the inhibition of the aromatase activity in the preoptic area and anterior hypothalamus. No increase of enzyme activity over the level seen in castrates was actually detected during the first 8 days of exposure to T. A moderate increase in AA was seen on day 16 and is probably responsible for the behavioral activation which was observed at the end of the experiment. |
| Databáze: | OpenAIRE |
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