# Alleviating head-mounted weight burden for neural imaging in freely-behaving rodents

## TL;DR

A new method using helium balloons reduces the weight burden on mice for better neural imaging during free movement.

## Contribution

A buoyancy-based method is introduced to counteract head-mounted weight in freely-behaving mice.

## Key findings

- A helium-filled balloon can counteract up to 7 g of head-mounted weight in mice.
- The method minimizes the impact of added weight on mice's motion behavior.
- The approach enables improved neural imaging without restricting animal movement.

## Abstract

The recently developed miniaturized head-mounted two-photon (2P) imaging devices have served as a valuable tool for neuroscientists, enabling real-time functional neural imaging in freely-behaving animals. Although the current 2P fiberscopes and miniscopes are lightweight, the weight of any potential additional accessories inevitably imposes a burden on the animal. Here, we present a buoyancy levitation method to alleviate head-mounted weight burden on mice. By utilizing the buoyance of a helium-filled balloon to counteract the additional weight of up to 7 g, mice’ motion behavior remains largely unaffected by the added load. Neuroimage analysis provides new insights into the effects of weight burden on neural activities. This easy-to-implement method offers a platform for studying neural network function in animals, effectively freeing them from the burden of head-mounted weight.

The online version contains supplementary material available at 10.1038/s41598-025-04300-0.