YAPICILAB - Neural Circuits

Neural Circuitry for Ingestion in Drosophila

Previously, we have identified local interneurons (IN1) in the fly taste center that receive input from sugar-sensitive pharyngeal taste neurons to control rapid and temporally precise sugar ingestion. To understand how this circuit regulates the timing of ingestion and how it is modulated by satiety, we are searching for neural populations downstream or upstream of IN1 neurons in the fly brain. Further anatomical and functional characterization of these neural subsets and their neurophysiological interactions with IN1 neurons will elucidate how flies regulate the temporal dynamics of food intake decisions.

Neural Correlates of Foraging in Flies

To quantify foraging decisions in flies, we are developing a virtual foraging assay (VR) based on the automated ball tracking system FICTRAC. In this VR-foraging task, nutrient-deprived flies will explore their environment and will be given liquid food at a defined point in VR space in the presence of certain olfactory or visual cues. We will monitor the fly’s trajectories before and after the food stimulus and in the presence or absence of visual/olfactory cues. The fly’s behavior will be tracked using a machine vision system that characterizes its position, velocity, and locomotion. Using the VR foraging task, we will identify neurons that regulate foraging decisions in flies.

Imaging Neural Circuit Dynamics During Ingestion in Mice

In mammals, food is detected by peripheral taste organs—such as the tongue, palate, and pharynx—whose sensory neurons project to the nucleus of the solitary tract (NTS) in the brainstem. The NTS integrates input from both gustatory and vagal sensory neurons, making it a key hub for regulating food intake. However, due to its deep brainstem location, studying NTS neurons has been technically challenging. To overcome this, we are developing a three-photon (3P) microendoscope that combines deep tissue imaging with GRIN lens technology. This tool will allow us to image taste-sensitive neurons in the NTS of awake mice during sugar ingestion and investigate how their activity varies with metabolic state.

Neural Correlates of Foraging in Mice

Foraging behavior in animals is strongly influenced by their metabolic state, which drives their specific needs. For example, a hungry or thirsty animal exhibits distinct behavioral goals, such as seeking food or water within their environment, guided by their internal physiological demands. To optimize their foraging strategies, animals must remember the locations of essential resources and recall these memories to adapt their behavior according to their current metabolic needs. This project aims to investigate the neural circuit mechanisms underlying how metabolic state, particularly hunger, modulates mouse foraging behavior. Particularly, we will explore the interaction between spatially-modulated neurons in the hippocampus and hunger-promoting Agouti-Related Peptide (AgRP) neurons in the hypothalamus, which are known to play a critical role in regulating food intake and energy balance.