Delay embedding of low-dimensional attractors of local field potentials from optogenetic data*

We investigated the effect of acute cocaine injection in conjunction with dopamine (DA) receptor antagonists on the medial prefrontal cortex (mPFC). In his study we used D1-like receptors antagonist SCH 23390 or D2-like receptors antagonists sulpiride. The goal of the study was to determine the changes in the gamma oscillations and their relationship to short term neuroadaptation that may mediate addiction. In this study we used 17 mice and recorded optogenetically evoked local field potentials (LFPs) in vivo. The optical stimulus was a brief 10 ms laser light pulse. Data preprocessing involved computing a Euclidian distance-based dendrogram to separate the 100 trials for each animal in disjoint clusters. The classifier is not perfect as it gives a minimum 20% overlap between the control data and DA receptor antagonists trials. We used the delay-embedding method to reconstruct neural activity attractor. The lag time was determined both using the correlation time and the mutual information methods.