Self-organization in neuronal networks with simultaneous excitatory and inhibitory homeostatic synaptic plasticity

• Applicant: Dr. Farzad Farkhooi
• Subject Area: Experimental and Theoretical Network Neuroscience ; Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 460662458

Homeostatic synaptic plasticity is a regulatory feedback mechanism whereby neurons compensate for excessive excitation and inhibition by adjusting their synaptic strengths. Despite substantial research on synaptic homeostasis, it is unclear how both excitatory and inhibitory synaptic inputs can concurrently self-organize to constrain network-level activity. This project will use theoretical tools to address this research gap. Using overwhelming evidence that spiking irregularity exhibits enormous similarity in various cortical areas across mammalian species, we postulate that homeostasis can regulate spiking irregularity statistics as well as output firing rate of neurons. An essential direct result of our proposed mechanism is the emergence of synaptic scaling law in the asynchronous-irregular state of networks with excitatory and inhibitory recurrent dynamics. In this project, we will further investigate the conditions under which synaptic homeostatic regulation generates stable population-level dynamics, in which spiking rate is broadly distributed, and synaptic weight distributions are skewed, as it is observed experimentally in recurrent circuits of excitatory and inhibitory neurons. Finally, we will experimentally test our theoretical predictions in a series of in-vitro experiments using optogenetic techniques.

• DFG Programme: Research Grants
• International Connection: France, USA
• Co-Investigator: Professorin Dr. Susanne Schreiber
• Cooperation Partners: Professor Dr. Alexander DeJesus; Professor Dr. David Hansel