Identification of neurons responsible for feeding behavior in the Drosophila brain

Abstract

Drosophila melanogaster feeds mainly on rotten fruits, which contain many kinds of sugar. Thus, the sense of sweet taste has evolved to serve as a dominant regulator and driver of feeding behavior. Although several sugar receptors have been described, it remains poorly understood how the sensory input is transformed into an appetitive behavior. Here, we used a neural silencing approach to screen brain circuits, and identified neurons labeled by three Gal4 lines that modulate Drosophila feeding behavior. These three Gal4 lines labeled neurons mainly in the suboesophageal ganglia (SOG), which is considered to be the fly's primary taste center. When we blocked the activity of these neurons, flies decreased their sugar consumption significantly. In contrast, activation of these neurons resulted in enhanced feeding behavior and increased food consumption not only towards sugar, but to an array of food sources. Moreover, upon neuronal activation, the flies demonstrated feeding behavior even in the absence of food, which suggests that neuronal activation can replace food as a stimulus for feeding behavior. These findings indicate that these Gal4-labeled neurons, which function downstream of sensory neurons and regulate feeding behavior towards different food sources is necessary in Drosophila feeding control.feeding behavior, sugar-sensing neurons, SOG, CAFE assay, proboscis extension response (PER) Citation:Sun F, Wang YJ, Zhou YQ, van Swinderen B, Gong ZF, Liu L. Identification of neurons responsible for feeding behavior in the Drosophila brain.

Motor control of fly feeding

“…The latter group also found two other GAL4s that stimulated proboscis extension and consumption when activated, and suppressed consumption when silenced (Sun et al 2014).…”

“…Another group reported that activation of the GAL4 containing the Fdg neurons triggered only moderate consumption, significantly less than starvation-induced consumption in controls, but confirmed that it triggers proboscis extension . A third group did find that the same GAL4 line could trigger consumption (Sun et al 2014). It is possible that Fdg acts along with other pathways to control consumption.…”

Targeted manipulation of neuronal activity in behaving adult flies

“…The different systems used for warming or cooling flies include temperature-controlled rooms or chambers, water baths, heating blocks or pads, or peltier plates (Marella et al 2012;Mann et al 2013;Flood et al 2013;Seeds et al 2014;Sun et al 2014;Hampel et al 2015). Chambers that house the flies have been designed with features that facilitate rapid warming such as mesh floors, or heat-conducting floors that are in direct contact with a heating element (Seeds et al 2014;Harris et al 2015).…”

Targeted manipulation of neuronal activity in behaving adult flies

“…An advantage of thermogenetic systems is that they can be relatively simple to build at low cost. The different systems used for warming or cooling flies include temperature-controlled rooms or chambers, water baths, heating blocks or pads, or peltier plates (Marella et al 2012;Mann et al 2013;Flood et al 2013;Seeds et al 2014;Sun et al 2014;Hampel et al 2015). Chambers that house the flies have been designed with features that facilitate rapid warming such as mesh floors, or heat-conducting floors that are in direct contact with a heating element (Seeds et al 2014;Harris et al 2015).…”