0000000000548644
AUTHOR
Leonardo Sacconi
Two-photon light-sheet microscopy for high-speed whole-brain functional imaging of zebrafish neuronal physiology and pathology
We present the development of a custom-made two-photon light-sheet microscope optimized for high-speed (5 Hz) volumetric imaging of zebrafish larval brain for the analysis of neuronal physiological and pathological activity. High-speed volumetric two-photon light-sheet microscopy is challenging to achieve, due to constrains on the signal-to-noise ratio. To maximize this parameter, we optimized our setup for high peak power of excitation light, while finely controlling its polarization, and we implemented remote scanning of the focal plane to record without disturbing the sample. Two-photon illumination is advantageous for zebrafish larva studies since infra-red excitation does not induce a …
Fast whole-brain imaging of seizures in zebrafish larvae by two-photon light-sheet microscopy
Light-sheet fluorescence microscopy (LSFM) enables real-time whole-brain functional imaging in zebrafish larvae. Conventional one photon LSFM can however induce undesirable visual stimulation due to the use of visible excitation light. The use of two-photon (2P) excitation, employing near-infrared invisible light, provides unbiased investigation of neuronal circuit dynamics. However, due to the low efficiency of the 2P absorption process, the imaging speed of this technique is typically limited by the signal-to-noise-ratio. Here, we describe a 2P LSFM setup designed for non-invasive imaging that enables quintuplicating state-of-the-art volumetric acquisition rate of the larval zebrafish bra…
Advanced fluorescence microscopy for in vivo imaging of neuronal activity
Brain function emerges from the coordinated activity, over time, of large neuronal populations placed in different brain regions. Understanding the relationships of these specific areas and disentangling the contributions of individual neurons to overall function remain central goals for neuroscience. In this scenario, fluorescence microscopy has been proved as the tool of choice for in vivo recording of brain activity. Optical advances combined with genetically encoded indicators allow a large flexibility in terms of spatiotemporal resolution and field of view while keeping invasiveness in living animals to a minimum. Here we describe the latest advancements in the field of linear and nonl…
Two-photon high-speed light-sheet volumetric imaging of brain activity during sleep in zebrafish larvae
Although it is well known that zebrafish display the behavioural signature of sleep, the neuronal correlates of this state are not yet completely understood, due to the complexity of the measurements required. For example, when performed with visible excitation light, functional imaging can disrupt the day/night cycle due to the induced visual stimulation. To address this issue, we developed a custom-made two-photon light-sheet microscope optimized for high-speed volumetric imaging. By employing infra-red light (not visible to the larva) for excitation, we are able to record wholebrain neuronal activity with high temporal- and spatial-resolution without affecting the sleep state. In two-pho…
Visualization_1
Volumetric recording of a single CRIW event shown as a selected subset of coronal sections. To produce the time lapse, original 16-bit depth images were converted into 8-bit and JPEG compressed. Scale bar: 100 ��m.
Visualization_2
3D rendering of the lag map shown in Fig. 4a. The lag value is color-coded as specified by the color bar. Scale bar: 100 ��m.
Visualization_1
Volumetric recording of a single CRIW event shown as a selected subset of coronal sections. To produce the time lapse, original 16-bit depth images were converted into 8-bit and JPEG compressed. Scale bar: 100 ��m.
Visualization_2
3D rendering of the lag map shown in Fig. 4a. The lag value is color-coded as specified by the color bar. Scale bar: 100 ��m.