TY - JOUR T1 - Spontaneous behaviors drive multidimensional, brain-wide neural activity JF - bioRxiv DO - 10.1101/306019 SP - 306019 AU - Carsen Stringer AU - Marius Pachitariu AU - Nicholas Steinmetz AU - Charu Reddy AU - Matteo Carandini AU - Kenneth D. Harris Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/04/22/306019.abstract N2 - Sensory cortices are active in the absence of external sensory stimuli. To understand the nature of this ongoing activity, we used two-photon calcium imaging to record from over 10,000 neurons in the visual cortex of mice awake in darkness while monitoring their behavior videographically. Ongoing population activity was multidimensional, exhibiting at least 100 significant dimensions, some of which were related to the spontaneous behaviors of the mice. The largest single dimension was correlated with the running speed and pupil area, while a 16-dimensional summary of orofacial behaviors could predict ∼45% of the explainable neural variance. Electrophysiological recordings with 8 simultaneous Neuropixels probes revealed a similar encoding of high-dimensional orofacial behaviors across multiple forebrain regions. Representation of motor variables continued uninterrupted during visual stimulus presentation, occupying dimensions nearly orthogonal to the stimulus responses. Our results show that a multidimensional representation of motor state is encoded across the forebrain, and is integrated with visual input by neuronal populations in primary visual cortex. ER -