Neurotrophic actions of dopamine on the development of a serotonergic feeding circuit in Drosophila melanogaster

BMC Neuroscience

Research Article

Wendi S Neckameyer¹  Parag Bhatt¹ 

[1] Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 South Grand Boulevard, 63104, Saint Louis, Missouri, USA;

关键词: Transgenic Line;    Larval Feeding;    Late Embryogenesis;    Neurite Length;    Central Nervous System Development;   

DOI  :  10.1186/1471-2202-13-26

 received in 2011-12-02, accepted in 2012-03-13,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundIn the fruit fly, Drosophila melanogaster, serotonin functions both as a neurotransmitter to regulate larval feeding, and in the development of the stomatogastric feeding circuit. There is an inverse relationship between neuronal serotonin levels during late embryogenesis and the complexity of the serotonergic fibers projecting from the larval brain to the foregut, which correlate with perturbations in feeding, the functional output of the circuit. Dopamine does not modulate larval feeding, and dopaminergic fibers do not innervate the larval foregut. Since dopamine can function in central nervous system development, separate from its role as a neurotransmitter, the role of neuronal dopamine was assessed on the development, and mature function, of the 5-HT larval feeding circuit.ResultsBoth decreased and increased neuronal dopamine levels in late embryogenesis during development of this circuit result in depressed levels of larval feeding. Perturbations in neuronal dopamine during this developmental period also result in greater branch complexity of the serotonergic fibers innervating the gut, as well as increased size and number of the serotonin-containing vesicles along the neurite length. This neurotrophic action for dopamine is modulated by the D2 dopamine receptor expressed during late embryogenesis in central 5-HT neurons. Animals carrying transgenic RNAi constructs to knock down both dopamine and serotonin synthesis in the central nervous system display normal feeding and fiber architecture. However, disparate levels of neuronal dopamine and serotonin during development of the circuit result in abnormal gut fiber architecture and feeding behavior.ConclusionsThese results suggest that dopamine can exert a direct trophic influence on the development of a specific neural circuit, and that dopamine and serotonin may interact with each other to generate the neural architecture necessary for normal function of the circuit.

【 授权许可】

CC BY   
© Neckameyer and Bhatt; licensee BioMed Central Ltd. 2012