Epp Väli

Neural plasticity is the ability of nervous system to change its activity in response to stimuli by reorganizing its structure, functions, or connections and this is the main cellular basis for memory. Activity-regulated genes play crucial roles in the formation of neuronal plasticity, and dysregulation of this process gives rise to various nervous system disorders. The neurotrophin BDNF is among the best-studied activity-regulated genes, and its polymorphisms are associated with impairments in human cognition. Our results also place the basic helix-loop-helix transcription factor TCF4, that is implicated in a variety of psychiatric and autism spectrum disorders, to the group of activity-regulated transcription factors. The aim of this project is to study gene regulation in intellectual disability and autism spectrum disorders with emphasis on disease-associated transcription factors TCF4, SATB2, FOXP1, and neurotrophin BDNF for finding new drug targets.

The nervous system consists of multiple cell types with distinct physiological specializations and gene expression patterns. In tissue, these cells form a complex, intertwined network that is subject to constant interaction between different cell types. This complexity poses a challenge for researchers in both separating cell types for analysis as well as studying interactions and information transfer between cells. In this application, we propose a molecular neuroscience study addressing both aspects. First, we are developing proteomics methods to allow analysis of newly synthesized proteins on a cell type-specific basis. Second, we shall use novel genetic tools for cell type-specific stimulation and gene expression analysis in primary co-cultures of neurons and astroglial cells. We shall use this system to probe gene expression signatures in neuron-astrocyte communication and determine the transmitters that form the basis of this communication.

Formation of new synapses, and alteration of the strength and stability of existing synapses are regarded as the main cellular basis for memory and long-term behavioral adaptations. Neuronal activity-regulated gene expression plays a crucial role in synaptic development and function, and its deregulation gives rise to various nervous system disorders. Knowledge about the regulatory mechanisms of activity-dependent gene expression is important both for understanding of nervous system function and for finding new drug targets. The aim of this project is to study the molecular mechanisms of neuronal activity-regulated gene expression, including transcription, translation and posttranslational modifications, in the nervous system health and disease. The studies are focused on two genes, the neurotrophin BDNF and the basic helix-loop-helix transcription factor TCF4.