[Frontiers in Bioscience 14, 4401-4415, January 1, 2009]

Neural mechanisms coordinating the female reproductive system in the locust

Angela B. Lange

Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Oviposition of a fertilized egg
3.1. The locust reproductive system
3.2. Integrative aspects of egg-laying
3.2.1. Mating
3.2.2. Digging behavior
3.2.3. Egg-laying
4. Neural control of reproductive structures
4.1. Innervation and neural substrate
4.1.1. Oviducts and ovaries
4.1.2. Spermatheca
4.1.3. Ovipositor valves and associated skeletal muscles
4.2. Functional significance of neural substrate
4.2.1. Oviducts and ovaries
4.2.2. Spermatheca
4.2.3. Ovipositor valves and associated skeletal muscles
4.2.4. Coordinated actions of CPGs and neural input
5. Modulation of behaviors
5.1. Neurochemicals as neuromodulators
5.1.1. Oviducts and ovaries
5.1.2. Spermatheca
5.1.3. Ovipositor valves and associated skeletal muscles
6. Perspectives
7. Acknowledgements
8. References

1. ABSTRACT

The production of viable offspring is a complex task, involving courtship, mating, maturation of eggs, ovulation, fertilization of eggs, and oviposition. With particular regard to the female, the reproductive system must produce eggs at the appropriate time and deposit them after fertilization in an appropriate place. Thus, the various structures of the reproductive system must be tightly coordinated and integrated. This review focuses on the female reproductive system and the neural mechanisms that lead to its integrated control. Central pattern generators, that are linked, control oviposition digging behavior, and contractions of the lower lateral and upper common oviducts that lead to retention of eggs. Sensory neurons also provide information about the presence of an egg in the genital chamber via a feedback loop to coordinate the spermatheca and thereby, fertilization. Neuropeptides and amines can modulate central and peripheral control mechanisms. These neural mechanisms are integrated such as to produce coordinated behavior, leading to the accomplishment of the ultimate task, that of producing viable offspring.