This is BlueBerry!

Talk to the brain remotely

Open-source wireless optogenetics for closed-loop control of animal behavior

BlueBerry Wireless Optogenetics and a mouseLearn more

Light, small and compact

The compact (14 x 10.5 x 7mm) and lightweight design (1.2gr) of the BlueBerry along with its ease of implementation and open source nature make it an ideal candidate for optogenetic studies on small freely moving rodents such as mice.

Battery

The battery-powered approach in designing BlueBerry enabled its use in various large scale environments without the need to adjust the experimental arena for wireless power transmission. BlueBerry uses special small Li-Ion rechargeable coin batteries from VARTA.

BLE communication

The BlueBerry includes a dedicated stand-alone bluetooth module (RN4871) responsible for receiving all necessary optogenetic stimulation protocol/channels.

Dedicated PCB

All electrical components are interconnected and mounted through a standard 2-layer compact PCB design.

Electronic components

The design utilizes readily available electronic components. A microprocessor (ATtiny85), is responsible for decoding all Bluetooth packets and delivering high-power pulses to the output channels via a two-channel MOSFET. This setup ensures efficient and reliable processing and control, leveraging the capabilities of standard, commercially available parts.

Standard connector

LED pulses are routed through standard miniature connectors, offering flexibility in the design of brain implants.



Interfacing the brain

Output channels of the Blueberry are plugged into a connector interfacing with implants fixed beneath the animal's scalp targeting either cortical layers or deep brain structures through customizable implants.

Superficial stimulation

Targeting superficial cortical regions using miniature high-power LEDs (60mW) mounted on flexible PCBs.

BlueBerry implants for cortical optogenetic stimulation

Deep brain stimulation

Targeting deep-brain regions by coupling high power LED with an optical fiber.

BlueBerry implants for deep brain optogenetic stimulation

BlueBerry closed-loop neuroscience applications

Controlling large scale navigation

The battery design of the BlueBerry device enables its use in large-scale, complex environments for optogenetic studies. We used BlueBerry with a multichannel flexible implant to bilaterally target the sensory barrel field, delivering optogenetic stimulation to create artificial sensory cues. Tracking the mice in real-time, we determined the future direction at each maze intersection. Choosing the correct path rewarded them with water at the middle of the arm connecting two intersections. This required freely moving mice to integrate the sensory information to make navigation decisions (turn left or right) in the maze.

BlueBerry wireless optogenetics for cortical stimulation

Shaping social dynamics

An important aspect of wireless optogenetics is its application in social settings, enabling targeted stimulation in multiple animals simultaneously. We utilized the BlueBerry device to activate the brain reward circuit (ventral tegmental area, VTA) using fiber-coupled LED implants in multiple mice. Stimulation was triggered upon the initiation of chasing behavior directed towards a conspecific higher in the dominance hierarchy. By implementing this in a closed-loop system with real-time tracking, we were able to modulate social dynamics, resulting in the formation of a moving train led by the most dominant animal in the cage.

BlueBerry wireless optogenetics for deep brain stimulation