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Hello Everyone,</div>
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<div class="elementToProof" style="direction: ltr;"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">Just a reminder of our CTN colloquium today starting at 3:30
p.m. in E5-2004.</span></div>
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<a href="https://sites.google.com/view/lnsbsp/home" id="OWAa2ad136d-fb56-7b7c-f819-2ce21fa8f6d9" class="x_OWAAutoLink" title="https://sites.google.com/view/lnsbsp/home" data-auth="NotApplicable" data-loopstyle="linkonly">
Milad Lankarany</a> from the Krembil Research Institute.</span></div>
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<div style="direction: ltr;"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><b>Title:</b> Using Computational Neuroscience and Neuromodulation Techniques to Uncover
Mechanisms of Neural Systems</span></div>
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<div style="direction: ltr;"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><b>Abstract:</b> Deep brain stimulation, as an invasive neuromodulation technique,
has been successfully used to reduce symptoms of movement disorders by delivering electrical pulses to the substructures of the basal ganglia and thalamus. Existing efforts to understand the mechanisms of action of DBS rely on detecting biomarkers during (or
after) delivering clinically approved high-frequency pulses and assessing their clinical outcomes. However, less consideration has been given to how DBS modulates information processing in the human brain. Specifically, it is not yet discovered how modulated
neural activities observed in a sub-cortical region represent dynamics of underlying circuitry. Building on our published data of in-vivo single-unit recordings in patients with Essential Tremor (n = 20), we discovered that neuronal dynamics (in the sense
of instantaneous firing rate) of thalamic ventral intermediate nucleus (Vim) in response to various frequencies of deep brain stimulation (DBS) can be explained by Balanced Amplification mechanism, an established theoretical framework that suggests the large
amplification of excitation — caused by either strong external input or positive recurrent circuitry — can be balanced by strong feedback inhibition. We developed a network rate model, together with a sequential optimization algorithm, that accurately reproduces
the instantaneous firing rate of Vim neurons, the primary surgical target of DBS for reducing symptoms of essential tremor, in response to low- and high-frequency DBS. Our study revealed that the computer simulation of a single population of Vim neurons (appeared
in our recent publication PMID: 37140523) cannot capture the dynamics of the firing rate, thus the presence of other neuronal populations is essential to track the firing rate reliably and mechanistically. Interestingly, our work suggests, in an unsupervised
manner, that the presence of an inhibitory neuronal population is necessary to replicate Vim firing rates across different DBS frequencies. We anticipate that our study provides a conceptual modeling framework to uncover mechanisms of information processing
in different DBS-modulated sub-cortical regions in the human brain.</span></div>
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</span></div>
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<p style="margin-top: 0px; margin-bottom: 0px;">_______________________________________________</p>
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<p style="margin-top: 0px; margin-bottom: 0px;">Dr. Sue Ann Campbell (she/her)</p>
<p style="margin-top: 0px; margin-bottom: 0px;">Professor and University Research Chair</p>
<p style="margin-top: 0px; margin-bottom: 0px;">Department of Applied Mathematics</p>
<p style="margin-top: 0px; margin-bottom: 0px;"><a href="https://uwaterloo.ca/centre-for-theoretical-neuroscience/" id="OWA538a49a7-9127-1c0c-0e4a-4c75307903d5" class="x_OWAAutoLink" title="https://uwaterloo.ca/centre-for-theoretical-neuroscience/" data-auth="NotApplicable" data-loopstyle="linkonly" style="margin-top: 0px; margin-bottom: 0px;">Centre
for Theoretical Neuroscience</a></p>
<p style="margin-top: 0px; margin-bottom: 0px;">Associate Dean, Research</p>
<p style="margin-top: 0px; margin-bottom: 0px;">Faculty of Mathematics</p>
<p style="margin-top: 0px; margin-bottom: 0px;">University of Waterloo</p>
<p style="margin-top: 0px; margin-bottom: 0px;">Waterloo ON N2L 3G1</p>
<p style="margin-top: 0px; margin-bottom: 0px;"><a href="https://www.math.uwaterloo.ca/~sacampbe/" id="OWA181f5c0a-8db0-e846-2ba9-3f316af96036" class="x_OWAAutoLink" data-auth="NotApplicable" data-loopstyle="linkonly" style="margin-top: 0px; margin-bottom: 0px;">https://www.math.uwaterloo.ca/~sacampbe/</a></p>
<p style="margin-top: 0px; margin-bottom: 0px;">President, <span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;">
<a href="https://caims.ca/" id="OWA4cbc41c6-5c97-3bf0-5f45-ca98dc9c5c05" class="x_OWAAutoLink" title="https://caims.ca/" data-auth="NotApplicable" data-loopstyle="linkonly" style="margin-top: 0px; margin-bottom: 0px;">Canadian Applied and Industrial Mathematics
Society</a></span></p>
<p style="margin-top: 0px; margin-bottom: 0px;"><br>
</p>
<p style="margin-top: 0px; margin-bottom: 0px;"><i>I acknowledge that I live and work on the traditional territory of the Chonnonton, Anishinaabeg and Haudenosaunee peoples. The University of Waterloo main campus is located on the Haldimand tract, the land
granted to the Six Nations that includes six miles on each side of the Grand River.</i></p>
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