Event:

Psychiatric diseases such as schizophrenia, bipolar disorder and autism spectrum disorders are considered neurodevelopmental synaptopathies. Compelling evidence has been obtained from large-scale genome-wide association studies which identified a plethora of genetic variations within hundreds of genes encoding components of the post-synaptic compartment and cellular as well as nuclear calcium signaling mediating excitation-transcription coupling.
There has been a tremendous progress in neuroscience research within the last decade to employ an array of molecular and cellular techniques studying the impact of individual genes.
Neuroscience is, however, methodologically lagging behind the cancer field with respect to large scale functional chemical and genetic screens. The difficulties of culturing postmitotic and matured neurons in sufficiently large amounts and the development of robust readouts for high-throughput screening are likely among the most important underlying reasons.
To adress some of these limitations, we have developed a functional genomics toolbox that is applicable in primary neurons to screen for thousands of chemical or genetic modulators. The sensitivity and robustness of the screen is largely driven by the pre-selection of genetic reporters that respond to neuronal activity with high signal-to-noise ratios.
A proof-of-principle will be presented in which an AAV-based RNAi library was screened for regulators of neuronal excitation and synapse-to-nucleus signaling using a genetic sensor based on the Synaptic-Activity-Response-Element (SARE). The assay principle relies on molecular barcodes which serve as quantitative reporters and at the same time as unique identifiers of the targeted genes. Upon synaptic stimulation, the screen identified hundreds of genes known to be involved in glutamatergic synapse-to-nucleus signaling including many
regulators of calcium- and cAMP-signaling. Reproducibility of the technical approach has been verified by a substantial overlap of hits between three independent screens. Moreover, the SARE reporter also allowed us to perform a screen with nearly 1k of clinically approved compounds in which several potential negative and positive modulators of neuronal and/or synaptic activity including several neuroleptics and anti-depressants were identified.
The presented genetic toolbox can be applied for the analysis of regulatory processes in mouse primary neurons and is currently evaluated for usage in human cellular disease models.