Strategies for optical control and simultaneous electrical readout of extended cortical circuits

J Neurosci Methods. 2015 Dec 30:256:220-31. doi: 10.1016/j.jneumeth.2015.07.028. Epub 2015 Aug 19.

Abstract

Background: To dissect the intricate workings of neural circuits, it is essential to gain precise control over subsets of neurons while retaining the ability to monitor larger-scale circuit dynamics. This requires the ability to both evoke and record neural activity simultaneously with high spatial and temporal resolution.

New method: In this paper we present approaches that address this need by combining micro-electrocorticography (μECoG) with optogenetics in ways that avoid photovoltaic artifacts.

Results: We demonstrate that variations of this approach are broadly applicable across three commonly studied mammalian species - mouse, rat, and macaque monkey - and that the recorded μECoG signal shows complex spectral and spatio-temporal patterns in response to optical stimulation.

Comparison with existing methods: While optogenetics provides the ability to excite or inhibit neural subpopulations in a targeted fashion, large-scale recording of resulting neural activity remains challenging. Recent advances in optical physiology, such as genetically encoded Ca(2+) indicators, are promising but currently do not allow simultaneous recordings from extended cortical areas due to limitations in optical imaging hardware.

Conclusions: We demonstrate techniques for the large-scale simultaneous interrogation of cortical circuits in three commonly used mammalian species.

Keywords: Auditory; Cranial window; ECoG; Epidural; Mouse; NHP; Optogenetics; Parvalbumin; Rat.

MeSH terms

  • Animals
  • Artifacts
  • Auditory Perception / physiology
  • Cerebral Cortex / physiology
  • Computer-Aided Design
  • Electric Impedance
  • Electrocorticography / instrumentation
  • Electrocorticography / methods*
  • Electrodes, Implanted
  • Equipment Design
  • Evoked Potentials / physiology
  • Macaca mulatta
  • Male
  • Mice, Transgenic
  • Neural Inhibition / physiology
  • Neurons / physiology
  • Optogenetics / instrumentation
  • Optogenetics / methods*
  • Photic Stimulation / methods
  • Rats, Long-Evans
  • Tin Compounds

Substances

  • Tin Compounds
  • stannic oxide