Network and behavioral correlates of prefrontal neurons

The prefrontal cortex is located in the front of the brain. This region is considered crucial for cognitive processes, such as decision-making, attention, and working memory. Neuronal activities in this region are found to correlate with cognitive features, as well as behavioral variables such as location and movement.

Within the rodent brain, there are distinct neuron types. Research indicates that the function of neurons, whether in relation to local networks or to behavior, is to some extent cell-type-specific.

In this thesis I explore methods to study neuronal cell-types in the rodent brain. Further, I use these methods to investigate the role of parvalbumin (PV) expressing interneurons in rats, in relation to network dynamics and behavioral features. This thesis contains 2 papers.

Paper I: We developed and described a method for concurrent electrophysiological recordings and optogenetic manipulation in freely moving rodents. Specifically, we designed a low-cost microdrive system and demonstrated its utility in freely moving rats and mice.

Paper II: We presented and characterized a novel PV-Cre rat line. We used this rat line to study the activity of prefrontal neuronal subpopulations in rats performing a goal-directed reward-seeking task. Consistent with previous findings, our data reveal neuronal tuning to both spatial and movement variables, with the strongest tuning observed for linear position. Additionally, in a subset of neurons, we observe activities that correlated with the conjunction of location and movement direction, referred to as the spatial context. While the activity of single neurons of all types were correlated with the spatial context, it was most prominently observed in the PV interneuron population.

List of scientific papers

I. Hoseok Kim*, Hans Brünner*, Marie Carlén. The DMCdrive: practical 3D-printable micro-drive system for reliable chronic multi-tetrode recording and optogenetic application in freely behaving rodents. Scientific Reports. 10 (2020), Article 11838. *Equal contribution
https://doi.org/10.1038/s41598-020-68783-9

II. Hans Brünner, Hoseok Kim, Sofie Ährlund-Richter, Josina Ana van Lunteren, Ana Paula Crestani, Konstantinos Meletis, Marie Carlén. Cell-type-specific representation of spatial context in the rat prefrontal cortex. iScience. Volume 27, Issue 5, 15 April 2024, 109743.
https://doi.org/10.1016/j.isci.2024.109743