Long-term all-optical interrogation of cortical neurons in awake-behaving nonhuman primates.

Niansheng Ju,Shiming Tang,Stephen L Macknik,Rundong Jiang,Susana Martinez-Conde,Adam Kohn

doi:10.1371/journal.pbio.2005839

Abstract

Whereas optogenetic techniques have proven successful in their ability to manipulate neuronal populations—with high spatial and temporal fidelity—in species ranging from insects to rodents, significant obstacles remain in their application to nonhuman primates (NHPs). Robust optogenetics-activated behavior and long-term monitoring of target neurons have been challenging in NHPs. Here, we present a method for all-optical interrogation (AOI), integrating optical stimulation and simultaneous two-photon (2P) imaging of neuronal populations in the primary visual cortex (V1) of awake rhesus macaques. A red-shifted channel-rhodopsin transgene (ChR1/VChR1 [C1V1]) and genetically encoded calcium indicators (genetically encoded calmodulin protein [GCaMP]5 or GCaMP6s) were delivered by adeno-associated viruses (AAVs) and subsequently expressed in V1 neuronal populations for months. We achieved optogenetic stimulation using both single-photon (1P) activation of neuronal populations and 2P activation of single cells, while simultaneously recording 2P calcium imaging in awake NHPs. Optogenetic manipulations of V1 neuronal populations produced reliable artificial visual percepts. Together, our advances show the feasibility of precise and stable AOI of cortical neurons in awake NHPs, which may lead to broad applications in high-level cognition and preclinical testing studies.

Highlights

Optogenetic techniques enable the functional characterization of neuronal populations and circuits with high spatial and temporal precision [1,2,3,4,5,6,7]
The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
We have overcome obstacles that prevented the combination of single- and two-photon (1P and 2P) optogenetic stimulation with 2P imaging in awakebehaving monkeys, retesting targeted individual cells and neuronal ensembles over periods that extended beyond 6 months

Summary

Introduction

Optogenetic techniques enable the functional characterization of neuronal populations and circuits with high spatial and temporal precision [1,2,3,4,5,6,7]. Previous research has recorded optogenetic activation using traditional electrophysiological techniques This approach is limited, because repeated electrode recordings in the same neurons are difficult to achieve across recording sessions in NHPs. In addition, examining opsin expression patterns in vivo within the area targeted by viral vector infusions, while maintaining the health of the neurons, is not currently possible without 2P laser-scanning microscopy [14,21,22,23,24]. Examining opsin expression patterns in vivo within the area targeted by viral vector infusions, while maintaining the health of the neurons, is not currently possible without 2P laser-scanning microscopy [14,21,22,23,24] These combined hurdles call for an all-optical interrogation (AOI) approach to the application of optogenetic methods in NHPs

Methods

Results

Discussion

Conclusion