Tag: two-photon

Laser power modulation: EOMs and AOMs

Fast laser power modulation in 2p systems is typically done with a Pockels cell. Conoptics sells one that is optimized for common Ti:Sapph systems, and that’s what many people end up using.

Pockels cells are a type…



Real-time tracking and 2p imaging with sub-ms timing

In this work, the authors used fast optical motion tracking and 2p imaging to measure the activity of individual neurons in freely moving animals. No surgery. No optical window. No restraint. And all the benefits of multiphoton…



PMT power supply

I was cleaning house a bit, and among my old files I found this, which might be worth sharing. Years ago I made a centralized power supply for a custom 2-photon imaging system I built. There were two epi…



Analysis algorithms: performance quantification and ground truth

We recently tweeted about a preprint from Eftychios A Pnevmatikakis and Andrea Giovannucci (code). The preprint is on motion correction for calcium imaging data. It is a nice quick read and discusses earlier work in the area….



Tons of 2p spectra – twophotondyes.com

 

Daniel Fiole is curating a nice resource for 2p cross sections: twophotondyes.com

There’s a lot here. It’s not just dyes, he has links for fluorescent proteins as well, and there’s 3p data



Ripple noise on PMTs in 2-photon imaging – Part 2

The recent post on ripple noise generated some comments and additional discussion. Go check out the comments on that post. For example, Peter Rupprecht shared some snapshots an oscilloscope display showing the signal from the BNC…



Ripple noise on PMTs in 2-photon imaging

Andrew Lim wrote in to discuss strategies on dealing with ripple noise in 2-photon imaging systems, particularly when using resonant scanners. He writes:

This isn’t so much a tip as a problem with resonant two-photon scopes that several…



Postdoc position with Duguid in Edinburgh

A world-class in vivo patch clamp electrophysiologist, Ian Duguid, is recruiting to his lab. Ian provides excellent training, and his lab is in a tremendous setting: Edinburgh. Ian’s also one of the current…



Constrained non-negative matrix factorization for calcium imaging data analysis

I tweeted about this last fall. This is the best algorithm I’ve seen for segmenting and extracting time course from calcium imaging data. Eftychios Pnevmatikakis developed the code in Liam Paninski’s lab. The work is…



CANDLE-J for denoising 2p data

Collaborative Approach for eNhanced Denoising under Low-light Excitation, or CANDLE, is a denoising algorithm specialized for the type of images that are acquired in 2-photon imaging applications. There’s code for both ImageJ and MATLAB available at that…



Upconversion: NIR in, vis out

Compared to visible (vis) light, near infrared (NIR) wavelength scatters less and is less absorbed in brain tissue. If your fluorescent target absorbs vis light, then one way to use NIR is to flood the area with molecules…



Imaging Course at Max Planck Florida

The Max Planck Florida Institute for Neuroscience is holding an imaging course Jan 11-20, 2016.
They have a really excellent line up of lecturers. A range of topics will be covered: two-photon imaging, FLIM, FRET, endoscopy, uncaging, optogenetics, SPIM, image analysis, instrumentation (alignment, system design), …

Applications are due in a few days, Nov….



FocusStack and StimServer for MATLAB

Dylan Muir and Bjorn Kampa created some MATLAB code for two-photon calcium imaging experiments. First up is FocusStack, which provides a suite of analysis tools. Next up is StimServer, which coordinates visual stimulus generation and presentation. The…



SIMA update – for 2p calcium imaging

SIMA has recently been updated (here’s the original Labrigger post):
From the SIMA team:

We have recently released updated versions of the SIMA & ROI Buddy tools for analysis of calcium imaging data (motion correction, segmentation, registration of…



Field of view = 3.5 mm with cellular resolution

In this preprint, Stirman et al. report achieving a 3.5 mm field of view with 2-photon excitation with cellular resolution. The design involves custom scan optics and a custom objective built in the SLAB. It’s an…