# Rapid three dimensional two photon neural population scanning

## TL;DR

This paper introduces a new method for 3D two-photon imaging of neural activity using electrically tunable lenses and spiral scanning algorithms to improve sampling rates.

## Contribution

The novel integration of electrically tunable lenses with the Adaptive Spiral Scanning algorithm enables higher theoretical sampling rates for 3D neural imaging.

## Key findings

- The proposed method achieves a theoretical sampling rate of 36.2Hz for 3D neural population scanning.
- MATLAB simulations using Izhikevich neurons validated the algorithm's performance improvements over existing techniques.

## Abstract

Recording the activity of neural populations at high sampling rates is a fundamental requirement for understanding computation in neural circuits. Two photon microscopy provides one promising approach towards this. However, neural circuits are three dimensional, and functional imaging in two dimensions fails to capture the 3D nature of neural dynamics. Electrically tunable lenses (ETLs) provide a simple and cheap method to extend laser scanning microscopy into the relatively unexploited third dimension. We have therefore incorporated them into our Adaptive Spiral Scanning (SSA) algorithm, which calculates kinematically efficient scanning strategies using radially modulated spiral paths. We characterised the response of the ETL, incorporated its dynamics using MATLAB models of the SSA algorithm and tested the models on populations of Izhikevich neurons of varying size and density. From this, we show that our algorithms can theoretically at least achieve sampling rates of 36.2Hz compared to 21.6Hz previously reported for 3D scanning techniques.