Mechanisms of Inter-areal Neuronal Communication

Tuesday 14 May 2024, 12:30 pm
PhD student
M.S. Schneider
prof. dr. M.A. Vinck
dr. G. Spyropoulos

"Inter-areal coherence between field potentials in the cortex is the subject of intensive research. It is assumed that coherence reflects phase-synchronization between neuronal populations and thus allows the brain to flexibly orchestrate communication between different brain areas according to behavioral and cognitive demands.

In my thesis, I try to shed light on the role of synchronization in inter-areal neuronal communication using neural recordings of different species, numerical simulations, and mathematical analysis. In Chapter 2, I examined an alternative hypothesis to the influential theory of communication through coherence. I hypothesized that coherence between two connected brain areas can be established based solely on incoming synaptic afferents from an oscillating sender brain area, without the need for neuronal entrainment in the receiving area. I examine this hypothesis using computational models of local field potentials and neural circuits, several neural recordings performed in macaque monkeys and mice as well as optogenetic experiments. In Chapters 3 and 4, I examined how synchronized activity propagates through the different neural processing stages.  Using neuronal recordings from the visual stream of macaque monkeys and mice, I show that high-frequency oscillations in the gamma frequency range mainly recruit inhibitory interneurons. Finally, I used a detailed biophysical model of different cell types in the visual cortex of mice to explain our observations.

Overall, my thesis work provides new insights into the role of phase-synchronization in inter-areal neuronal communication and the propagation of rhythmic activity in the cortex."