Extended field-of-view ultrathin microendoscopes for high-resolution two-photon imaging with minimal invasiveness

Elife. 2020 Oct 13;9:e58882. doi: 10.7554/eLife.58882.

Abstract

Imaging neuronal activity with high and homogeneous spatial resolution across the field-of-view (FOV) and limited invasiveness in deep brain regions is fundamental for the progress of neuroscience, yet is a major technical challenge. We achieved this goal by correcting optical aberrations in gradient index lens-based ultrathin (≤500 µm) microendoscopes using aspheric microlenses generated through 3D-microprinting. Corrected microendoscopes had extended FOV (eFOV) with homogeneous spatial resolution for two-photon fluorescence imaging and required no modification of the optical set-up. Synthetic calcium imaging data showed that, compared to uncorrected endoscopes, eFOV-microendoscopes led to improved signal-to-noise ratio and more precise evaluation of correlated neuronal activity. We experimentally validated these predictions in awake head-fixed mice. Moreover, using eFOV-microendoscopes we demonstrated cell-specific encoding of behavioral state-dependent information in distributed functional subnetworks in a primary somatosensory thalamic nucleus. eFOV-microendoscopes are, therefore, small-cross-section ready-to-use tools for deep two-photon functional imaging with unprecedentedly high and homogeneous spatial resolution.

Keywords: 3D microprinting; Aberration correction; microendoscopes; mouse; network dynamics; neuroscience; thalamus; two-photon imaging.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal
  • Endoscopes
  • Female
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Fluorescence, Multiphoton / instrumentation
  • Microscopy, Fluorescence, Multiphoton / methods*
  • Neurons / physiology
  • Thalamus / diagnostic imaging*
  • Thalamus / physiology