Neuronal networks of the vertebrate motor system - evolutionarily conserved forebrain control strategies.

Our overarching goal is to unravel the mechanisms by which the forebrain determines which motor behaviour to select.

We have shown that the pallium/cortex and basal ganglia of the lamprey are conserved with regard to neuronal properties, synapses and connectivity and can serve as a blueprint for the mammalian forebrain.

This unexpected discovery implies that these complex circuits had evolved already at the dawn of vertebrate evolution, 500 million years ago.

Our aims are: Perform scRNAseq of the lamprey cortex, basal ganglia and dopamine cells in SNc, and compare with the mouse which cell types are conserved.Complement our analysis with: 1) the intrinsic function of the basal ganglia output stage (substantia nigra pars reticulata, SNr) - neuronal properties and lateral inhibition. 2) the input stage to striatum with the synaptic properties and short and long-term plasticity of the thalamic and cortical afferents.We have created a unique simulation platform for striatum (Hjorth et al.,2020 mouse) with the correct density of striatal projection neurons and interneurons with detailed dendritic morphology and membrane properties, connectivity, cortical, thalamic and dopamine input (mouse).

This allow us to perform “in silico experiments”, which cannot be performed experimentally, and analyse under what conditions a selection of action can be achieved as well as motor learning. We will in addition, extend the striatal simulation platform to include all parts of the basal ganglia.