Deep 2-photon imaging and artifact-free optogenetics through transparent graphene microelectrode arrays

TLDR

Recent advances in multi‑photon microscopy and optogenetics have revolutionized neuronal recording and manipulation, but integrating these optical modalities with electrical recordings is hampered by light‑induced artifacts. The study introduces a transparent graphene microelectrode array that removes light‑induced artifacts, allowing simultaneous 2‑photon imaging, optogenetic stimulation, and cortical recording. The array is fabricated with crack‑free, residue‑free graphene electrodes that provide high optical transmittance, enabling 2‑photon imaging to ~1 mm depth. This technology permits investigation of neuronal activity across scales from single neurons to large populations.

Abstract

Abstract Recent advances in optical technologies such as multi-photon microscopy and optogenetics have revolutionized our ability to record and manipulate neuronal activity. Combining optical techniques with electrical recordings is of critical importance to connect the large body of neuroscience knowledge obtained from animal models to human studies mainly relying on electrophysiological recordings of brain-scale activity. However, integration of optical modalities with electrical recordings is challenging due to generation of light-induced artifacts. Here we report a transparent graphene microelectrode technology that eliminates light-induced artifacts to enable crosstalk-free integration of 2-photon microscopy, optogenetic stimulation, and cortical recordings in the same in vivo experiment. We achieve fabrication of crack- and residue-free graphene electrode surfaces yielding high optical transmittance for 2-photon imaging down to ~ 1 mm below the cortical surface. Transparent graphene microelectrode technology offers a practical pathway to investigate neuronal activity over multiple spatial scales extending from single neurons to large neuronal populations.