Modelling Neuromodulated Information Flow and Energetic Consumption at Thalamic Relay Synapses

Recent experimental and theoretical work has shown that synapses in the visual pathway balance information flow with their energetic needs, maximising not the information flow from the retina to the primary visual cortex (bits per second), but instead maximising information flow per concomitant energy consumption (bits of information transferred per number of adenosine triphosphate molecules necessary to power the corresponding synaptic and neuronal activities) [5, 10, 11]. We have previously developed a biophysical Hodgkin-Huxley-type model for thalamic relay cells, calibrated on experimental data, and that recapitulates those experimental findings [10]. Here, we introduce an improved version of that model to include neuromodulation of thalamic relay synapses’ transmission properties by serotonin. We show how significantly neuromodulation affects the output of thalamic relay cells, and discuss the implications of that mechanism in the context of energetically optimal information transfer at those synapses.