Circuit Diagrams

Many animals rely on their ability to navigate to the source of airborne odor plumes for survival. Studies dating back a century have shown that insects combine mechanosensory and olfactory cues to navigate, surging upwind when detecting odor but go crosswind or downwind when losing the signal. They also use bilateral information from their two antennae to turn toward higher odor concentrations. We recently discovered that in addition to wind direction and odor gradient, fruit flies detect the direction of motion of odors, independent of the wind.

Project Summary Mother-infant bonding is a key relationship that lays a foundation for wellness throughout life. Social recognition is an important component of this relationship, as infants imprint on the smell of their mothers and use olfaction to distinguish their mother from others.

PROJECT SUMMARY: Animals constantly detect different environmental stimuli and change their behavior or physiology based on their internal state. How animals integrate the external multiple sensory information with the internal state is largely unclear. The specific goal of this proposal is to explore the neural circuits and mechanisms of internal state- dependent modulation of multiple sensory integrations. We will draw on a powerful, versatile, and relatively simple genetic model, Drosophila, to address the neural mechanisms of taste-temperature integration.

THEORETICAL FRAMEWORK: Vision and touch share a critical function—perception of 3D object shape. We use vision and touch both alternatively and simultaneously to recognize, understand, and interact physically with real world objects, based on detailed apprehension of their 3D shapes and mechanical functionality.

Abstract Movements are measurable outputs of the nervous system and simple movements can be combined to compose complicated behaviors. We use limb tracking and connectome analyses to map the neural circuits controlling the elemental leg movements in Drosophila grooming. The organization of the pre-motor networks for this innate, sequential behavior will show a successful solution for a complex motor control problem and reveal generalizable connectivity motifs whose computational functions can be experimentally tested.

Project Summary To navigate and guide locomotion in a complex 3D environment, humans and animals must make countless judgments of their direction of self-motion, or heading. Each of these is a multisensory perceptual decision, able to achieve greater accuracy and precision by combining signals from the visual, vestibular, and kinesthetic senses. At the same time, the brain must decide when to commit to a course of action (e.g., to quickly change direction to avoid an obstacle), and make predictions of the likelihood of success in that action.

PROJECT SUMMARY In social species, social relationships can exert profound influences on individuals’ behavioral and physiological states. In particular, social interactions can help reduce negative emotional state induced by physical or psychological stressors, a phenomenon known as social buffering. Social buffering provides an important means by which the social environment facilitates stress coping and resilience and benefits health and well-being.

Abstract Sleep occupies a large part of our lives and is widely believed to perform essential functions. During sleep, the neuronal rules of engagement and population dynamics are clearly different than waking. There is extensive evidence that one primary function of sleep is to consolidate memories formed during waking. Recent work, however, suggests that sleep may also actively alter neural connections to achieve forgetting (‘unlearning’). How the brain balances learning and forgetting, exactly how sleep contributes, and the ultimate effects on ensembles and behavior are unknown.

PROJECT SUMMARY Survival in dynamic environments demands that behaviors are flexible and adaptive. An organism must make predictions about which actions lead to rewards, calculate how outcomes differ from those predictions (prediction errors), and adapt a behavioral strategy accordingly. Neurons encoding prediction errors can be found throughout many reward-related brain structures, with the highest densities in the VTA and the lateral habenula (LHb).

SUMMARY We are proposing a new approach to a hybrid imaging modality that has been called “b+g” or “pamma-positron” Imaging [Gri07] that promises to simultaneously overcome 1) the sensitivity limits of single-gamma-ray-photon emission imaging, 2) the challenge of distinguishing between two different positron-emitting isotopes, and 3) the physics-based spatial resolution limits inherent in radioisotope imaging based on detection of positron- annihilation photons alone [Lan14].