Multi-photon cellular imaging of neural activity in rodents typically requires head fixation. In this paper, the authors describe a magnet-based setup that allows for voluntary, self-controlled head fixation and, longitudinal imaging of the same population of neurons in rats, with reliable micrometer-scale registration across trials. This is combined with a reflective conical cannula that boosts the collection of emitted fluorescence. The authors validate the system by imaging hippocampal neuron population responses in transgenic rats, showcasing daily performance of hundreds of trials of head-fixed cued behavior over months, and even years. This setup could enable lifetime home-cage imaging of activity without any issues of mechanical head fixation.

Original reference: Nat. Commun. 15, 4154 (2024)