"Illuminating the Brain: New Tools to Understand Neuromodulation and Neuronal Networks"

On behalf of the 'Enlightening Neuroscience: Optogenetics from green algae to the brain' Group, Prof. Olivia Masseck will give a talk titled "Illuminating the Brain: New Tools to Understand Neuromodulation and Neuronal Networks" as part of the ongoing Student/Postdoc-Run Speaker Series (SPRSS).

Abstract:

Understanding how neuronal networks generate complex behavior is one of the major goals of Neuroscience. Neurotransmitter and Neuromodulators are crucial for information flow between neurons and understanding their dynamics is the key to unravel their role in behavior.

A new red-shifted genetically encoded calcium indicator (PinkyCaMP)  based on mScarlet will be presented. PinkyCaMP surpasses existing redshifted calcium sensors in brightness, photostability and compatibility with optogenetics. PinkyCaMP is well tolerated from neurons and shows no toxicity or aggregation neither in culture nor in vivo.

In addition our lab recently developed a new family of genetically encoded serotonin (5-HT) sensors (sDarken) on the basis of the native 5-HT1A receptor and circularly permuted GFP (Kubitschke et al. 2022) . sDarken 5-HT sensors are bright in the unbound state and diminish their fluorescence upon binding of 5-HT. Sensor variants with different affinities for serotonin were engineered to increase the versatility in imaging of serotonin dynamics.  As demonstrated here, the designed sensors show excellent membrane expression, have high specificity and a superior signal-to-noise ratio, detect the endogenous release of serotonin and are suitable for in vivo imaging. However, to overcome current limitations in intensity based fluorescent measurements, we employ lifetime imaging as a new tool for the readout of serotonin.