The role of striatal inhibition for action selection

by Mikael Lindahl (CB/CSC/KTH)

Friday 3 Oct 2014, 10:00 → 11:00 Europe/Stockholm

F0 (F0)

Synaptic inhibition is crucial for controlling and shaping signaling in the basal ganglia circuits. The medium spiny neurons (MSN) are the projection neurons of the striatum, the input nucleus of the basal ganglia, and they receive inhibitory inputs from mainly three different sources: collateral input from neighboring MSNs, feedforward inhibition from fast spiking interneurons and oligosynaptic inhibition via part of the globus pallidus externa (GPe) (Mallet et al., 2012; Tepper et al., 2008), the latter in turn controlled from the subthalamic nucleus (STN). I will present a semi-quantitative spiking neural network model of the striatum, STN, GPe and SNr, with synapse dynamics and connectivity set based on available experimental data. Cortical inputs are emulated to both striatum and STN. The model reproduces network dynamics measured during in vivo experiments and seen in response to both slow wave and active brains states in control and dopamine depleted animals (Mallet et all, 2008). I will illustrate how feedback, feedforward and oligosynaptic mediated inhibition differentially could control the excitability of MSNs in striatum. Furthermore, I will also use the model framework to investigate to what extent the inhibitory connectivity within stratum can enhance the basal ganglia hypothesized role in action selection.