KSEF RDE: The Influence in the Development of the Central Nervous System with Limiting Sensory Gravitational Input in a Fast Developing Animal Model

Key words: microgravity, simulation, neural, development, sensory, behavior, anatomy Areas of research expertise: Neural development, neural plasticity, NASA medicine, modulation of neural development, Synaptic physiology. Exomedicine option: Micro gravity simulation Title: The influence in the development of the central nervous system with limiting sensory gravitational input in a fast developing animal model The proposed research plan is to investigate neuronal plasticity within a neural circuit with altered sensory input in relation to simulating microgravity. Synaptic connections, growth of axons and dendrites are dependent on neural activity in relation to the inputs received. Mechanisms underlying synaptic plasticity at defined synapses have been analyzed for decades; however, there have been few studies surrounding the plasticity of sensory-motor circuits as a result of altered sensory neuronal activity throughout development. The alterations in synaptic connections between neurons within an entire sensory-motor circuit as a result of decreased activity-based fine tuning during development can be readily assessed in this model. Larval Drosophila melanogaster offer many advantages to investigate the development of neural circuits based on altered input. Rapid development which can be regulated via temperature, genetic manipulability to alter activity in defined subsets of neurons with temperature (Gal-80 driven lines) or modern optogenetics (Channel rhodopsin for excitation or halohrhodopsin for inhibition) are feasible approaches we will use to simulate microgravity or increased gravity by temporal control in tweaking sensory neuronal activity of subclasses of "md neurons" which provides the larvae with the sense of gravitation force. Aim 1: Develop a paradigm to test dysfunction in sensing gravity and mechanical touch when sensory neurons during embryo and larval development have been dampened or silenced in activity by the use of halohrhodopsin expression and optically control. Aim 2: Examine class IV sensory neurons axonal projections (GFP labeled and confocal microscopy) into the CNS in larvae that have optogenetically been suppressed in activity with various periods of time the embryo and larval development. Aim 3: After simulated microgravity by dampened sensory activity provided normal gravitation force or overstimulation and re-asses behavior and neural development for circuit restructuring.