Nathan Johnston is a second-year Ph.D. student in neurobiology at the University of Utah. He completed his bachelor’s degree in molecular and cellular biology at the University of Washington in 2020 and came to the University of Utah the following autumn. As an undergraduate, he worked in Garret Stuber’s lab at the University of Washington,where he used fluorescence in situ hybridization and functional transcriptomics to map cell types in the mammalian habenula. His graduate work focuses on using a combination of calcium imaging and computational techniques to understand how the computations underlying spatial navigation is altered in contralateral neglect.
Outside of the lab, Johnston is involved in a number of outreach and volunteer organizations including Science for U, which connects local students with scientists for mentorship through the school year, and the Three Minute Thesis competition which challenges graduate students to communicate their thesis work as clearly and succinctly as possible.
Principal Investigator: Nicholas Frost
Fellow: Sophia Flatt
Undergraduate Fellow Project:
Navigation requires an internal representation of the relative position of locations or objects so that an individual may utilize the most appropriate path to travel from one position to another. Hemispatial neglect is a condition characterized by deficits in the ability to attend to stimuli localized to one hemisphere — usually contralateral to a lesion in the parietal cortex — caused by a failure to reconcile allocentric and egocentric representations. Translation of information between these coordinate systems is critical both for us to reliably represent our surroundings, but also to permit flexible navigation strategies. To understand how the parietal lobe affects the representation of information on egocentric and allocentric coordinate systems we have developed a novel optogenetic model of hemispatial neglect, which permits us to record the activity of many neurons simultaneously during navigation and then measure how the activity of neurons in the prefrontal cortex and hippocampus changes following optogenetic silencing of the parietal cortex. Students will have an opportunity to learn to perform and analyze calcium data from freely moving animals engaged in a navigational task, as well as optogenetic and chemogenetic modulation of circuit function.