Electrophysiological and immunohistochemical investigation of homeostatic mechanisms to compensate differences in the architecture of neural networks

• Applicant: Dr. Nelly Daur
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: from 2011 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 193493992

Nervous systems generate and regulate neural activity for behavior and learning. Neural circuits that are responsible for specific functions have to be both flexible to allow learning and adaptive behavior, and stable to ensure constant function and endurance of learned behaviors. In order to reconcile the need to change synaptic connections and intrinsic neuronal properties with the need to maintain long-term stability, regulatory mechanisms have to be employed that keep plastic changes within functional boundaries. This proposal focuses on how the nervous system can produce stable output activity, both over time, and across individuals. Homeostatic mechanisms that maintain stable neuronal activity over time are relatively well described at the level of single neurons and pairs of synaptic partners, but little is known about how this translates into the stable performance of an entire network of neurons. Network activity is relatively straightforward to monitor in small circuits that produce rhythmic motor behaviors, like the crustacean stomatogastric ganglion. Across individuals, the rhythmic patterns produced by these circuits are very consistent in the relative timing between different groups of neurons, even though the network architecture is variable, as some neuron types exist in different numbers of copies. The goal of the experiments proposed here is to identify which parameters of the synaptic interactions on the neuronal and neuromuscular level and intrinsic neuronal properties are regulated to compensate for the different network architectures.It is of fundamental importance to understand the balance of homeostasis and plasticity in the brain, because this balance is lost in neurodegenerative diseases like Alzheimer¿s and epilepsy, with devastating consequences. In addition, unbalanced plasticity can hinder recovery from stroke or injury of the central nervous system.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Dirk Bucher