HND · Mechanisms of Human Neuronal Development and Functional Integration in Neural Network
FP7 — People (Marie Curie Actions)
- Duration
- 2011-05-01 → 2015-06-30
- EU contribution
- €232,677
- Participants
- 1
- Scheme
- MC-IOF
Lines connect the coordinator with its partners.
Results in brief
Mechanisms of Human Neuronal Development and Functional Integration in Neural Network
Human cell reprogramming technologies offer access to live human neurons from patients and provide a new alternative for modeling neurological disorders in vitro. Neural electrical activity is the essence of nervous system function in vivo. Therefore, we examined neuronal activity in media widely used to culture neurons. We found that classic basal media, as well as serum, impair action potential generation and synaptic communication. To overcome this problem, we designed a new neuronal medium (BrainPhys basal + serum-free supplements) in which we adjusted the concentrations of inorganic salts, neuroactive amino acids and energetic substrates. We then tested that this new medium adequately supports neuronal activity and survival of human neurons in culture. Long-term exposure to this physiological medium also improved the proportion of neurons that were synaptically active. The medium was designed to culture human neurons but also proved adequate for rodent neurons. The improvement in BrainPhys basal medium to support neurophysiological activity is an important step toward reducing the gap between brain physiological conditions in vivo and neuronal models in vitro. (Bardy et al. PNAS 2015) Cell reprogramming technologies are revolutionizing medical research. An important challenge faced by neurobiologists is cellular heterogeneity, and better ways to identify/sort relevant cell types are needed. Human neural progenitors develop into electrophysiologically mature neurons at variable rates, providing challenges to in vitro studies of neurological disorders. Based on functional properties, we defined five electrophysiological types of neurons, which followed a developmental continuum. Whole-cell electrophysiology remains the gold-standard for functional evaluation. However, the large-scale analyses needed for translational studies require additional high-throughput molecular methods. We examined neuronal cultures derived from induced-pluripotent-stem-cells by combining single-cell measurements of electrophysiological activity, morphology and the transcriptome. This analysis showed strong correlations between action potential physiology, synaptic activity, dendritic complexity and gene expression. These correlations pointed out the importance of isolating functionally comparable neuronal samples. Our single-cell RNA sequencing analysis revealed genes that are expressed specifically in electrophysiologically mature human neurons. We used this molecular signature to isolate functional neurons. Altogether, this study opens up a new avenue for efficient large-scale prediction and analysis of functional cell types based on molecular signatures. Breaking the barrier of efficiently discerning mature electrophysiological types of neurons will expand the relevance of neuronal models in vitro. (Bardy et al. in revision 2015)
Data: CORDIS, © European Union
Project objective
Despite the exponentially growing burden that neurodevelopment or neurodegenerative diseases represent in public health, the therapies are mostly inexistent or very limited. Intensive fundamental research on the biological mechanisms of neurological disorders is strongly needed to discover and validate pharmacological treatments. At the same time, there is a pressing need for treatment that would compensate the loss of neurons occurring in a multitude of neurological disorders. Rare clinical trials have promoted the feasibility of stem cell-based therapy in the human brain. However, when significant, the benefits of the treatment were transient, and did not completely stop the progression of the disease. Unfortunately, the physiological causes of success or failure of the grafts remain unclear. It seems thus crucial to develop new human experimental models to resolve those issues.In this context, the HND proposal is guided by the objective to study the key mechanisms of human neuronal development and more precisely to clarify how human neural progenitors may functionally integrate neural networks. To reach this aim, I will have to achieve the following specific objectives: 1) Developing human experimental neuron-based models, and 2) Developing new strategies to insure the appropriate maturation, integration, function and fate of neural progenitors. The HND project will be performed on neural cell culture obtained from human tissue, by using state-of-the-art genetic reprogramming techniques. The originality of the proposal is to combine several cutting-edge genetic and physiological technologies to approach the topic at cellular and neural network levels in living tissue.The outcomes of the project will be particularly important to research aiming to identify the biological mechanisms underlying neurological pathologies and validate pharmacological treatments, as well as to restorative cell therapies.
Original text from CORDIS.
Participants
- UNIVERSITE D'AIX MARSEILLE · MarseilleCoordinatorFrance
Links
Data: CORDIS, © European Union