Linking brain activity across scales with simultaneous opto- and electrophysiology

Abstract

The brain enables adaptive behavior via the dynamic coordination of diverse neuronal signals across spatial and temporal scales: from fast action potential patterns in microcircuits to slower patterns of distributed activity in brain-wide networks. Understanding principles of multiscale dynamics requires simultaneous monitoring of signals in multiple, distributed network nodes. Combining optical and electrical recordings of brain activity is promising for collecting data across multiple scales and can reveal aspects of coordinated dynamics invisible to standard, singlemodality approaches. We review recent progress in combining opto-and electrophysiology, focusing on mouse studies that shed new light on the function of single neurons by embedding their activity in the context of brain-wide activity patterns. Optical and electrical readouts can be tailored to desired scales to tackle specific questions. For example, fast dynamics in single cells or local populations recorded with multi-electrode arrays can be related to simultaneously acquired optical signals that report activity in specified subpopulations of neurons, in non-neuronal cells, or in neuromodulatory pathways. Conversely, two-photon imaging can be used to densely monitor activity in local circuits while sampling electrical activity in distant brain areas at the same time. The refinement of combined approaches will continue to reveal previously inaccessible and under-appreciated aspects of coordinated brain activity.

A Translaminar Spacetime Code Supports Touch-Evoked Traveling Waves

“…Noise artifacts from laser scanning were minimal when imaging GCaMP6s, and were easily filtered out with a recursive notch filter 35 (Figure S1D-E). While alternative techniques can be used to further reduce noise artifacts, such as using red-shifted GCaMP sensors, or enhancing the electrode transparency with graphene 29,36 ; nanomesh arrays 37 , or other novel materials [38][39][40] , our recordings revealed that nanoporous gold was sufficient for near artifact-free imaging while allowing for dense patterning. This platform allowed us to record from hundreds of L2/3 cells in the field of view (FOV) with clearly detectable touch-evoked LFP (Figure 1E, Figure S1F-G).…”

Understanding the nervous system: lessons from Frontiers in Neurophotonics

“…In recent years, diverse strategies have been developed to merge in vivo neurophotonics with in vivo neuroelectronics, including transparent surface electrode arrays and penetrating electrode shanks with integrated light sources, light guides, and photodetectors. 76 – 84 For optical modalities that interface with brain tissue through large numerical aperture objectives that have a wide footprint and working distance of a few millimeters, unobstructed access to the surface is necessary. One such modality is 2-photon microscopy.…”