Galinanes, G. | Search bioRxiv

bioRxiv2025

BlueBerry: Closed-loop wireless optogenetic manipulation in freely moving animals

Optogenetics is a powerful approach for linking neural activity to behavior by enabling precise manipulation of defined neuronal populations. Recent advances in wireless technologies have led to remotely controlled optogenetic devices that facilitate the study of more complex behaviors, including social interactions. However, implementing real-time, automated, closed-loop experiments in large-scale, naturalistic environments and in groups of interacting animals remains challenging. Moreover, many existing devices are difficult to reproduce, requiring specialized engineering expertise or fabrication facilities that are not widely available. Here we introduce BlueBerry (www.OptoBlueBerry.org), a lightweight (1.4 g), battery powered, multi-channel wireless optogenetic device that is openly available for the scientific community and can be assembled entirely from off-the-shelf-components. BlueBerry combines robust long-range wireless communication with flexible control of stimulation parameters, making it particularly suited for behavior-triggered optogenetic experiments in large arenas and in multiple freely interacting animals. We demonstrate that BlueBerry can not only guide decision making during large-scale navigation, but also deliver individually controlled, behavior-triggered optogenetic stimulation to multiple freely interacting mice, enabling modulation of social dynamics in real-time. The open availability, modular design, and straightforward integration with existing behavioral frameworks make BlueBerry a practical and scalable tool for systems neuroscience.

neuroscience↗

bioRxiv2018

Optical alignment device for two-photon microscopy

Two-photon excitation fluorescence microscopy has revolutionized our understanding of brain structure and function through the high resolution and large penetration depth it offers. Investigating neural structures in vivo requires gaining optical access to the brain, which is typically achieved by replacing a part of the skull with one or several layers of cover glass windows. To compensate for the spherical aberrations caused by the presence of these layers of glass, collar-correction objectives are typically used. However, the efficiency of this correction has been shown to depend significantly on the tilt angle between the glass window surface and the optical axis of the imaging system. Here we expand these observations and characterize the effect of the tilt angle on the collected fluorescence signal with thicker windows (double cover glass) and compare these results with an objective devoid of collar-correction. Finally, we present a simple optical alignment device designed to rapidly minimize the tilt angle in vivo and align the optical axis of the microscope perpendicularly to the glass window, thereby significantly improving the imaging quality. The performance of the device is demonstrated in an in vivo setting and a tilt-correction procedure is described, enabling the accurate alignment (<0.2{degrees}) of the cover glass with the imaging plane in only few iterations.

neuroscience↗