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

Our overarching goal is to unravel the forebrain mechanisms that determine which motor behaviour to select.

The pallium/cortex and basal ganglia of the lamprey are conserved regarding neuronal properties, synapses and connectivity and can serve as a blueprint for the mammalian forebrain.

Our aims are:  I.To analyse the intrinsic function of the basal ganglia (matrix portion of striatum) and its role for initiation of movement through parallel experiments and detailed simulations (lamprey, mouse and (humans)).

One focus is the output of the basal ganglia (SNr), where we unexpectedly show input from the motor cortex (M1 and M2). SNr neurons target downstream motor centres. Moreover, we explore the similarity between lamprey, rodent and human striatal neurons.

II.To analyse the circuitry underlying the evaluation of behaviour, with a focus on the striosomal portion of striatum and its control of the level of activity in dopamine neurons. These circuits are considered to be important for motor learning.

III.We have created a unique simulation platform for the striatum (Frost Nylén et al. 2023) with the correct density of neurons, dendritic morphology, membrane properties, connectivity, cortical and dopamine input (mouse).

This allows us to perform “in silico experiments”, which cannot be performed experimentally, and analyse under what conditions a selection of action can be achieved. The striatal simulation platform will be extended to an integrated basal ganglia platform