Light Sculpting paper in Nature Methods
This week our latest paper got published in Nature Methods. The paper is entitled “Brain-wide 3D imaging of neuronal activity in Caenorhabditis elegans with sculpted light“.
In this paper, we introduce wide-field temporal focusing (WF-TEFO), a two-photon techniquebased on light-sculpting. It effectively decouples the parameters governing the lateral (spot) size of a light beam and its axial resolution. Thus, this technique allows exciting a large area in the lateral dimension while retaining exceptional resolution in the axial direction, also known as optical sectioning. In the actual setup, this is akin to creating a thin “disc” of excitation light. WF-TEFO is well suited for fast volumetric imaging, as it scanning is reduced to one dimension only.
In our experiments we tailored the properties of our WF-TEFO to record, with high temporal and spatial resolution, the activity of neurons in the head ganglia of C. elegans in vivo. Read below the abstract of our paper:
Recent efforts in neuroscience research seek to obtain detailed anatomical neuronal wiring maps as well as information on how neurons in these networks engage in dynamic activities. Although the entire connectivity map of the nervous system of C. elegans has been known for more than 25 years, this knowledge has not been sufficient to predict all functional connections underlying behavior. To approach this goal, we developed a two-photon technique for brain-wide calcium imaging in C. elegans using wide-field temporal focusing (WF-TEFO). Pivotal to our results was the use of a nuclear-localized, genetically encoded calcium indicator (NLS-GCaMP5K) that permits unambiguous discrimination of individual neurons within the densely-packed head ganglia of C. elegans. We demonstrate near-simultaneous recording of activity of up to 70% of all head neurons. In combination with a lab-on-a- chip device for stimulus delivery, this method provides an enabling platform for establishing functional maps of neuronal networks
Here is a link to the 3D videos that are produced by our WF-TEFO imaging setup.
This paper has been a collaborative effort with the neuroscience research group of Manuel Zimmer, also at the IMP, which studies the neuro-circuitry underlying chemosensing in C. elegans.