Major:
Mentor(s):
Faculty Sponsor(s):
Faculty Sponsor's Department(s):
Project Title:
Project Description:
In fruit flies, descending neurons (DNs) serve as an information bottleneck to convey command information from the brain to the ventral nerve cord (VNC), the motor control center which is analogous to the spinal cord in humans. Limb movements are generated by local circuits in the spinal cord/VNC, which in turn are controlled by the circuits in the brain. However, the knowledge about how DNs recruit motor neurons and control rhythmic motor output is limited. To observe this, we used fly grooming as a model to initially understand how and to determine which DNs interacted. Fly grooming is a highly ordered coordination effort, which is done whenever flies are covered in dust for hygiene upkeep and clean themselves by alternating between body-directed grooming and leg rubbing. From the optogenetic screen of fly grooming behavior, we have found the activation of a group of descending neurons, DNg11, can induce bilateral front leg rubbing, even with unilateral activation. This suggests that DNg11 interacts with other neurons, possibly in the brain or VNC, to create the bilateral motor sequenced grooming event. Recently, researchers generated the VNC electron microscopy data set (EM) for use in Neuroglancer. Neuroglancer is a novel and powerful web-based analysis tool, which provides an AI program to trace neurons with EM data of VNC and is used to study the whole connectome circuits. The only caveat is that the auto-segmentation the AI creates has several proofreading mistakes, such as with strongly contrasting or poorly stacked EM slices (i.e. improper merging or cutting of neurons). To further investigate this motor circuitry, we propose to study the DNg11 connection circuits in the VNC by reconstructing them in the EM through the Neuroglancer platform. This is done by comparing the proofread descending projections in Neuroglancer with confocal imaging of DNg11, we will screen the candidates most associated with DNg11 in VNC and further study their downstream partners in the VNC. This will provide new knowledge about how the DNs are involved in motor control, bridging the information from the brain to the VNC in animals.