Circuit Investigations With Open-Source Miniaturized Microscopes: Past, Present and Future.

Daniel Aharoni,Tycho M Hoogland

doi:10.3389/fncel.2019.00141

Abstract

The ability to simultaneously image the spatiotemporal activity signatures from many neurons during unrestrained vertebrate behaviors has become possible through the development of miniaturized fluorescence microscopes, or miniscopes, sufficiently light to be carried by small animals such as bats, birds and rodents. Miniscopes have permitted the study of circuits underlying song vocalization, action sequencing, head-direction tuning, spatial memory encoding and sleep to name a few. The foundation for these microscopes has been laid over the last two decades through academic research with some of this work resulting in commercialization. More recently, open-source initiatives have led to an even broader adoption of miniscopes in the neuroscience community. Open-source designs allow for rapid modification and extension of their function, which has resulted in a new generation of miniscopes that now permit wire-free or wireless recording, concurrent electrophysiology and imaging, two-color fluorescence detection, simultaneous optical actuation and read-out as well as wide-field and volumetric light-field imaging. These novel miniscopes will further expand the toolset of those seeking affordable methods to probe neural circuit function during naturalistic behaviors. Here, we will discuss the early development, present use and future potential of miniscopes.

Highlights

The past 5 years have seen a flurry of open-source development with respect to miniaturized fluorescence microscopes for neuroscience applications, further advancing already existing technology and extending access to a much broader scientific user base (Cai et al, 2016; Liberti et al, 2016, 2017; Jacob et al, 2018b; Juneau et al, 2018; Liang et al, 2018; Scott et al, 2018; Skocek et al, 2018; Zhang et al, 2018)
We summarize and compare the different ongoing open-source developments and their potential for neuroscientific inquiries
The development of open-source miniscopes has given a big boost to neuroscientists that want accessible, affordable and understandable tools to image the vertebrate brain during naturalistic behavior

Summary

Introduction

The past 5 years have seen a flurry of open-source development with respect to miniaturized fluorescence microscopes (miniscopes) for neuroscience applications, further advancing already existing technology and extending access to a much broader scientific user base (Cai et al, 2016; Liberti et al, 2016, 2017; Jacob et al, 2018b; Juneau et al, 2018; Liang et al, 2018; Scott et al, 2018; Skocek et al, 2018; Zhang et al, 2018). It has a field-of-view of 800 by 600 μm (640 by 480 pixels) using an optical design similar to that of the first-generation UCLA Miniscope with a GRIN lens as an objective and an achromatic lens to focus an image on the CMOS imaging sensor.

Results

Conclusion