Swathi Anil: Modeling transcranial magnetic stimulation (TMS) protocols in recurrent neuronal networks with homeostatic structural plasticity
| When |
Oct 13, 2020
from 05:15 PM to 05:45 PM |
|---|---|
| Where | Zoom Meeting. Meeting ID and password will be sent with e-mail invitation. You can also ask Fiona Siegfried for Meeting ID and password. |
| Contact Name | Katharina Heining |
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Abstract
Swathi Anil1, Han Lu2,3, Julia V. Gallinaro 2*, Stefan Rotter2*, Andreas Vlachos1,2,4,5,*
1 Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
2 Bernstein Center Freiburg, University of Freiburg, Freiburg, 79104, Germany. 3Institute of Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France
4 Brain Links Brain Tools, Albert Ludwig University
5 Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
* Joint senior authors
A defining feature of neural tissue is the ability to respond to specific stimuli with functional and structural adaptations. Such changes at synaptic contact sites, i.e., synaptic plasticity, are considered fundamental for complex brain functions. In past decades activity-dependent plasticity mechanisms have been extensively studied, with Hebbian and homeostatic plasticity being cornerstone concepts. However, it remains unclear how these two mechanisms, which are based on positive or negative feedback, respectively, can co-exist in the same networks, neurons, and even synapses. Interestingly the effects of classic Hebbian plasticity paradigm, e.g., local tetanic electrical stimulation, have not yet been systematically evaluated for their effects on homeostatic synaptic plasticity induction. In the present study, we adopted a computational approach to explore the effects of classic long-term potentiation (LTP)- and long-term depression (LTD)-protocols in an inhibition-dominated random network of leaky integrate-and-fire point neurons, which undergoes structural remodeling based on firing rate homeostasis. Each neuron in this network has a set point of intracellular calcium concentration, reflecting its firing rate. Any change induced by external input is counteracted by changes in structural connectivity to bring firing rates back to this set point. We examined the results of classic plasticity protocols, using trains of short, i.e., 0.5 ms DC pulses (e.g., 100 pulses at 100 Hz; 900 pulses at 1 Hz), and recorded the resulting changes in firing rate and network connectivity. Results obtained in a small network (500 neurons) suggest that reliable network remodeling can be triggered. In particular, we found differential effects of structural plasticity among the stimulated and non-stimulated neurons, and between these groups. In an attempt to explore plasticity protocols used in clinical practice for (non-)invasive brain stimulation we evaluated the outcome of FDA approved transcranial magnetic stimulation (TMS) protocols. These results provide a new perspective on TMS-effects that outlast the stimulation period, and hence a new perspective for the development of therapeutic strategies that go beyond classic „LTP-like „or „LTD-like“ plasticity mechanisms.
Acknowledgements: This work was supported by Federal Ministry of Education and Research German (BMBF-01GQ1804A to AV).
