May 21, 2010
School of Biotechnology, Amritapuri
Amrita’s Dr. Shyam Diwakar will travel to Singapore in June to speak at Neuro Talk 2010, a world congress of neuroscientists. Dr. Shyam’s talk will be part of the Neuromathematics, Neurophysics, Neuroinformatics and Computation Neurobiology track at the conference.
Dr. Shyam will be one of only eight speakers from India. Invited guest speakers represent countries from all around the world.
Titled Neuronal Models and Exploration of Network Properties: A Case Study into Cerebellar Granular Layer Models and Local Field Potential Modeling, Dr. Shyam’s talk will focus on some key elements of his current research work. See Talk Abstract »
“The cerebellum granular layer has been the object of intense experimental and theoretical investigation,” he explains. “We made a detailed biophysical neuron model to reconstruct the local field potential extracted from a net of neurons seen in granular layer.”
What is the cerebral granular layer and why is its study important?
“One of the biggest open challenges that biologists, mathematicians and engineers face, is the understanding of the complex computations that take place in our brain,” further explained Dr. Shyam.
“Among the most interesting parts of the brain, is the `little brain’, otherwise known as the cerebellum. The granular layer forms the input stage of the cerebellum in which information coming from the peripheral and central nervous systems converge through mossy fibers.”
“The cerebral granular layer has, by far, the smallest (∼ 5μm) and the most numerous (∼ 10^11 ) neurons to be found in humans.”
“Understanding how the granular layer processes information appears critical to understanding the cerebellar function, since signals coming into upper cortical layers are provided by the granular layer.”
Dr. Shyam’s talk will address impact of learning behavior, plasticity in brain and some pharmacological phenomena with predictions on disease conditions, all based on high-detail mathematical models and neuronal biophysics.
“The cerebellum is of critical importance for sensory-motor control and learning and its disruption causes a dramatic neurological syndrome called ataxia,” he added. “Cerebellar dysfunction causes a condition similar to Alzheimer’s syndrome, Parkinson’s disease and epilepsy.”
A Ph.D. from University of Milan in Computational Neuroscience, Dr. Shyam obtained an undergraduate degree in engineering from Amrita. His current research focus is the detailed modeling of cerebellar cells and its network functions. Please visit the webpage of Computational Neuroscience and Mathematical Biology at ASBT to learn more about his work.
Abstract: The cerebellum granular layer has been the object of intense experimental and theoretical investigation. A critical prediction (Marr, 1069) is that coding of mossy fibre activity is sparse, in that it involves only a small percentage of the available neurons for any given input stimulus. Using detailed biophysical neuron model (Diwakar et al, 2009), jitterred repetitive convolution and Blind source estimation techniques to reconstruct the local field potential extracted from a net of neurons seen in granular layer. The study yields insight into how LTP/LTD functions. The model was able to reproduce the impact of Golgi cells (which generate inhibit granule cells) and of NMDA receptors (which regulate mossy fiber – granule cell repetitive transmission) in shaping the LFP. Moreover, the model predicted that changes in release probability and intrinsic neuronal excitability, which have both been reported in single granule cell recordings in vitro, need to combine in order to determining the LFP changes caused by repetitive sensory stimulation.