Dopamine and Mushroom Bodies in Drosophila: Experience-Dependent and -Independent Aspects of Sexual Behavior

  1. Wendi S. Neckameyer
  1. Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104 USA

Abstract

Depletion of dopamine in Drosophila melanogaster adult males, accomplished through systemic introduction of the tyrosine hydroxylase inhibitor 3-iodo-tyrosine, severely impaired the ability of these flies to modify their courtship responses to immature males. Mature males, when first exposed to immature males, will perform courtship rituals; the intensity and duration of this behavior rapidly diminshes with time. Dopamine is also required for normal female sexual receptivity; dopamine-depleted females show increased latency to copulation. One kilobase of 5′ upstream information from theDrosophila tyrosine hydroxylase (DTH) gene, when fused to theEscherichia coli β-galactosidase reporter and transduced into the genome of Drosophila melanogaster, is capable of directing expression of the reporter gene in the mushroom bodies, which are believed to mediate learning acquisition and memory retention in flies. Ablation of mushroom bodies by treatment of newly hatched larva with hydroxyurea resulted in the inability of treated mature adult males to cease courtship when placed with untreated immature males. However, functional mushroom bodies were not required for the dopaminergic modulation of an innate behavior, female sexual receptivity. These data suggest that dopamine acts as a signaling molecule within the mushroom bodies to mediate a simple form of learning.

Footnotes

    • Received December 17, 1997.
    • Accepted April 14, 1998.
| Table of Contents