The Evolutionary Origin of the Forebrain Control of Motion — from Ion Channels to Behavior
Our main aim is to unravel the cellular bases of motor behaviour with a focus on the mechanisms underlying selection of behaviour and the neural bases of in particular goal-directed locomotion and related steering, orienting and eye movements. The role of the cortex (pallium), basal ganglia, habenulae and optic tectum are in focus, while we have previously elucidated the brainstem-spinal cord microcircuits underlying locomotion. This in turn requires a detailed knowledge of which nerve cells take part, how they talk to each other through synaptic interaction and an understanding of the intrinsic function of these networks.
The properties of different classes of nerve cells within the networks can vary greatly and are determined by the palette of ion channels expressed and also other gene products. Moreover, the properties of the different neurons can be modified by different monoaminergic, peptidergic and other G-protein-mediated receptors that act to fine-tune cellular or synaptic properties of the different network neurons.
The operation of the networks at a millisecond level is due to glutamate, glycine and GABA synaptic transmission. Essentially, our research extends from ion channels and synapses to network mechanisms and behaviour utilising a multitude of techniques from patch clamp and cellular imaging to multi-scale modelling, tracing and immuno¬histochemical techniques and studies of behaviour. We utilise preferentially the lamprey as model organism, which also has proved important from an evolutionary perspective. We have shown that the circuits in the cortex/pallium, basal ganglia, habenulae, optic tectum and the brainstem-spinal cord have been conserved throughout vertebrate phylogeny to a very unexpected degree. Our recent findings have shown that the lamprey forebrain has all components of the mammalian forebrain – a finding that has radically changed the view on the evolutionary origin of the vertebrate forebrain. The basic organisation had evolved 560 million years ago rather than 300 million years ago as previously believed.
Throughout the vertebrates, several basic motor behaviours are controlled by neuronal networks (CPGs) located in the brainstem (e.g. swallowing, breathing) and the spinal cord (e.g. locomotion). The basal ganglia are similarly organised in lamprey and primates, and play a crucial role in the selection of motor behaviours and the habenulae encodes value-based information. The optic tectum plays an important role for visuomotor coordination and orienting/evasive movements.
The projects are supported by Karolinska Institutet, the Swedish Research Council and the EU.
Direct Dopaminergic Projections from the SNc Modulate Visuomotor Transformation in the Lamprey Tectum.
Neuron 2017 Nov;96(4):910-924.e5
Ciliated neurons lining the central canal sense both fluid movement and pH through ASIC3.
Nat Commun 2016 Jan;7():10002
Tectal microcircuit generating visual selection commands on gaze-controlling neurons.
Proc. Natl. Acad. Sci. U.S.A. 2015 Apr;112(15):E1956-65
Independent circuits in the basal ganglia for the evaluation and selection of actions.
Proc. Natl. Acad. Sci. U.S.A. 2013 Sep;110(38):E3670-9
Sten Grillner - Professor, group leader
Alexander Kozlov - Research engineer
Andreas Kardamakis - Assistant Professor
Johanna Frost Nylén - PhD Student
Juan Pérez-Fernández - Postdoc
Brita Robertson - Senior laboratory coordinator
Daichi Suzuki - Postdoc
Shreyas Suryanarayana - PhD student
Peter Wallén - Associate professor