Background: Deep-Brain Imaging & Stimulation for Freely Behaving Animals
A long-standing objective in neuroscience has been elucidating how neural activity relates to diverse brain functions in vivo. Researchers have attempted to address this by developing a wide-range of all-optical tools for simultaneously imaging and manipulating neural activity in freely-moving animals. To be viable for in vivo neuroscience research, these techniques necessitate high temporal resolution to image and manipulate neuronal firing at physiological speed, and high spatial resolution to image and manipulate specific individual neurons or regions. In addition, any components that are to be mounted onto a live animal must be as light as possible (e.g. <2g or lighter), in order to help extend the length of experiments and reduce extraneous factors (e.g. stress) allowing for more natural animal behaviour to be observed during experiments. These are the technical standards set for these technologies.
- White Paper: "All-Optical Deep Brain Imaging & Stimulation Tools for In Vivo Neuroscience" is an overview of the existing all-optical imaging and stimulation tools, and compares advantages and disadvantages of these techniques.
Commercially Available Systems
The OASIS Implant In Vivo Imaging and Stimulation System by Mightex: "One Platform, Any Experiment"
OASIS Implant is capable of performing simultaneous all-optical recording (e.g. Calcium imaging) and manipulation (e.g. optogenetic stimulation) in the deep brain of a freely behaving animal to observe neural circuit activity with high cellular resolution. Compatible with high-sensitivity research-grade cameras, OASIS Implant enables researchers to acquire high quality deep-brain images with low noise and high linearity, enabling quantitative data analysis. In addition, with multiple illumination ports and multiple filter slots, OASIS Implant can be reconfigured by end users to precisely fit their specific experimental needs. Equipped with both wide-field and targeted optogenetic stimulation capabilities (when combined with, for example, Mightex's Polygon400), OASIS Implant allows scientists to simultaneously perform Calcium imaging and targeted optogenetic stimulation with pin-point accuracy to stimulate individual neurons (but without unwanted stimulation of the neighboring neurons). Moreover, it is also capable of multi-color imaging and optogenetic stimulation. Another key benefit of the OASIS Implant system for behavioral neuroscience is its super light-weight head mount. Since both deep-brain imaging and stimulation are delivered through a very thin imaging fiber, the overall weight of the head-mounted fixture is as little as 0.7g (compared to approximately 2~3g with a head-mounted camera), which minimizes stress experienced by the animal, and allows for the duration of the experiments to be extended. All of these features combined make the OASIS Implant an ideal research tool for in vivo experiments.
Below is a GCaMP imaging video acquired using the OASIS Implant system in the striatum of a live and awake mouse. The video on the right shows the freely behaving mouse with the imaging fiber attached. (Videos and recordings provided courtesy of a neuroscience researcher.)