Mechanistic analysis of ERP in rodents

The aim of this task is to gain a better understanding on the nature of the evoked related potentials (ERPs) induced by a current stimulation of the secondary motor cortex (M2), which has been adopted for generating the cortical perturbation in task PCI-like measure in rodents. Since a current stimulation is not physiological, it can be difficult to predict the exact brain response. We, therefore, stimulated M2 of head-restrained awake rats with current pulses of different intensities, in order to approximate a stimulus-response function. We repeated these measures during general anaesthesia to verify if differences in the ERPs could be trivially explained by reduced brain excitability induced by the anaesthetic compound. We then explored the extension of the brain areas that are recruited in the response by simultaneously recording from several cortical regions and from the hippocampus, by mean of chronically implanted stainless-steel and tungsten electrodes respectively.