ARS | Publication request: Biogenic amines in the stable fly Stomoxys calcitrans L. (Diptera: Muscidae): tissue localization and roles in feeding and reproduction

Submitted to: Agricultural Research International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 23, 2011
Publication Date: N/A

Technical Abstract: Biogenic amines, such as serotonin (5-hdroxytryptamine [5-HT]) and octopamine (OA), play critical roles as neurotransmitters and neuromodulators that control or modulate many behaviors in insects, such as feeding and reproduction. Neurons immunoreactive (IR) to 5-HT and OA were detected in the central nervous system (CNS) of the stable fly, using immunohistochemical techniques. The location and pattern of the 5-HT IR neurons are described and compared for these two different developmental stages. Anatomical features of the fly feeding system were analyzed in third instar larvae and adult flies using a combination of histological and immunohistochemical techniques. In third instar larvae, the cibarial dilator muscles are located within the cibarial pump skeleton and are innervated by 5-HT IR neurons in nerves arising from the brain. There are four pairs of nerves arising from the frontal surface of the larval brain that innervate the cibarial pump muscles, pharynx, and muscles that control the mouth hooks, respectively. Similarly, many 5-HT IR neurons were found in both the brain and the thoracico-abdominal ganglia in the adult, some of which innervate the cibarial pump dilator muscles and the stomatogastric muscles. The male reproductive system was found to be innervated by both 5-HT and OA IR neurons, while only OA IR neurons were found to innervate the female reproductive system. The functional roles of serotonin and octopamine in regulating stable fly feeding and reproduction are currently being investigated using pharmacological and electrophysiological techniques. The data generated from this study would contribute to our understanding on the physiological roles of biogenic amines in regulating critical fly behaviors. The work may also help discover novel molecular targets that can be used for developing new generation of fly control technologies.