Mechanism underlying starvation-dependent modulation of olfactory behavior in Drosophila larva

Abstract

Starvation enhances olfactory sensitivity that encourage animals to search for food. the molecular mechanisms that enable sensory neurons to remain flexible and adapt to a particular internal state remain poorly understood. Here, we study the roles of GABA and insulin signaling in starvationdependent modulation of olfactory sensory neuron (oSn) function in the Drosophila larva. We show that GABA B-receptor and insulin-receptor play important roles during oSn modulation. Using an OSN-specific gene expression analysis, we explore downstream targets of insulin signaling in OSNs. our results suggest that insulin and GABA signaling pathways interact within oSns and modulate oSn function by impacting olfactory information processing. We further show that manipulating these signaling pathways specifically in the OSNs impact larval feeding behavior and its body weight. these results challenge the prevailing model of oSn modulation and highlight opportunities to better understand oSn modulation mechanisms and their relationship to animal physiology.

Transcriptome Profiling of Starvation in the Peripheral Chemosensory Organs of the Crop Pest Spodoptera littoralis Caterpillars

“…Whereas it has been demonstrated that the olfactory plasticity observed in fasted animals results from enhanced presynaptic activity in the antennal lobes mediated via the short neuropeptide F [22] and possibly insulin and GABA signaling [23], we show here that the nutritional status clearly impacts peri-receptor events in the olfactory detection process.…”

“…In this later study, starvation was shown to increase sNPF receptor signaling, which in turn enhanced presynaptic activity in Drosophila olfactory neurons. It has also been shown that insulin signaling interacts with GABA signaling to impact ORN function upon starvation in Drosophila [ 23 ], potentially impacting the expression of downstream genes. Thus, modulation of the peripheral olfactory activity makes an important contribution to food search behavior in response to starvation.…”

Loss of Smell in COVID-19 Patients: Lessons and Opportunities

“…In fact, highest density of central insulin receptors and highest concentration of insulin in mammalian brain are found in the olfactory bulb (Havrankova et al, 1981). Insulin signaling plays a significant role in satiety-dependent modulation of smell sensitivities (Bargmann, 2012;Taghert and Nitabach, 2012;Ko et al, 2015;Slankster et al, 2020). Like ACE2, insulin receptors are expressed on surface of both OSNs and glia (Nassel et al, 2013;Musashe et al, 2016).…”

A neural circuit linking two sugar sensors regulates satiety-dependent fructose drive inDrosophila

“…The most straightforward way is to elicit changes in sensitivity and attractiveness to specific food-related cues. Important examples of this phenomenon have been described in both the olfactory system (Ko et al, 2015;Lin et al, 2019;Root et al, 2011;Sayin et al, 2019;Slankster et al, 2020), and the gustatory system of flies (Inagaki et al, 2012;Jaeger et al, 2018;LeDue et al, 2016;Musso et al, 2019). In taste, a particular area of focus has been sugar detection.…”