New publication: Theta oscillations are not essential for grid cell coding
In order to navigate you have to keep track of direction, speed and distance. Grid cells constitute a mental map of space almost like the brains GPS. It has been suggested that rhythmic brain waves (theta oscillations) carry information about speed and direction - essential for grid cell coding.
Happy authors: Lepperød, Christensen, Lensjø, Fyhn & Hafting
Optogenetic activation of parvalbumin-positive (PV+) cells in the MSA enabled selective pacing of local field potential (LFP) oscillations in MEC. During optogenetic stimulation, the grid cells were locked to the imposed pacing frequency but kept their spatial patterns. Phase precession was abolished, and speed information was no longer reflected in the LFP oscillations but was still carried by rate coding of individual MEC neurons. Together, these results support that theta oscillations are not critical to the spatial pattern of grid cells and do not carry a crucial velocity signal.
Optogenetic pacing of medial septum parvalbumin positive cells disrupts temporal but not spatial firing in grid cells.
Lepperød, Christensen, Lensjø, Buccino, Yu, Fyhn & Hafting
Open access at: https://advances.sciencemag.org/content/7/19/eabd5684
Science Advances 05 May 2021: Vol. 7, no. 19, eabd5684