Project 1.

Cholinergic neuromodulation is important for memory and memory-guided navigation. However, little is known about the temporal dynamics in cholinergic modulation. This project investigates temporal dynamics of cholinergic activity as a function of locomotion and sensory inputs. We use fiber photometry in freely behaving mice to monitor cholinergic activity in the hippocampus and medial entorhinal cortex during temporally precise manipulation of visual, auditory, and olfactory cues. The expected results will generate knowledge about neural mechanisms that are often impaired in neurological and psychiatric disorders.

Project 2.

Grid cells in the medial entorhinal cortex are considered the ‘GPS’ signal in the brain. This project studies the temporal dynamics in the formation of a cognitive map represented by grid cells in the medial entorhinal cortex as a function of sensory inputs and how the temporal dynamics in the formation of a cognitive spatial map align with subcortical dynamics of cholinergic signals. Towards this aim, we will use multiple single unit recordings of grid cells in freely behaving mice and fiber photometry recordings of cholinergic activity in the medial septum.

Project 3.

Grid cells in the medial entorhinal cortex are believed to serve path integration, a basic navigational strategy that is conserved across species. However, little is known about the neural mechanisms that give rise to grid cell firing and underly path integration. This project tests if cholinergic modulation is necessary for grid cell firing. We use optogenetic manipulation of cholinergic projection neurons in combination with grid cell recordings in the medial entorhinal cortex to test hypotheses on the role of cholinergic modulation for grid cell firing.