@article {70373,
	title = {Raster photostimulation of large-scale neural populations},
	journal = {bioRxiv},
	year = {2026},
	month = {2026 Apr 24},
	abstract = {<p>Neural computations are implemented by distributed neural populations that often span multiple brain areas. Causal photo-activation experiments done simultaneously with neural recordings can greatly improve our understanding of these computations, but such methods are typically limited to small subsets of neurons in restricted fields of view. Here we describe a new system called raster photostimulation for photo-activating and recording thousands of neurons, over a short 300 ms time window and over a large 5 mm field-of-view on a two-photon mesoscope. The photo-activation is precisely matched to the neural recording configuration, as it uses the same optical path, although with a different laser that is independently gated. We demonstrate pixel-level precision, frame-by-frame mask updating, and single-frame photostimulation of thousands of neurons. While this method lacks the precise temporal control of alternative methods, it compensates with ease-of-use, spatial precision, cost of implementation and by pushing the limits on the number of near-simultaneously stimulated neurons.</p>
},
	doi = {10.64898/2026.04.21.719951},
	url = {https://www.biorxiv.org/content/early/2026/04/24/2026.04.21.719951},
	author = {LaFosse, Paul K. and Flickinger, Daniel and Jaindl, Georg and Drinnenberg, Antonia and Gr{\o}dem, Sverre and Lensj{\o}, Kristian K. and Ramakrishnan, Charu and Siverts, La{\textquoteright}Akea and Zeng, Hongkui and Tasic, Bosiljka and Daigle, Tanya L. and Fyhn, Marianne and Deisseroth, Karl and Stringer, Carsen and Pachitariu, Marius}
}
