Ion Channels & Neurobiophysics Lab
Department of Biophysics, University of Delhi, South Campus
Computational and Mathematical Modeling of Memory and Plasticity.
We are developing computational and mathematical models for both synaptic and intrinsic plasticity. These models are based on Hodgkin–Huxley and FitzHugh–Nagumo models of action potential. In particular our interest is the threshold of action potential and the role of noise. In recent studies it is observed that other than synaptic plasticity, neurons can modulate their own excitability, which plays a crucial role in information encoding and learning. This aspect of neuronal plasticity is being addressed through our mathematical model.
Role of Mitochondrial Ion Channels in Neuron's Life and Death.
We are studying the role of ion channels like Voltage Dependent Anion Channel (VDAC) and various kinases, e.g. PKA, MAP Kinase, CaM Kinase, in mitochondia mediated apoptosis. We are combining biophysical and electrophysiologica studies to investigate the structure-function relationship of VDAC with various pro-apoptotic agents and other ligands e.g. phytochemical compounds, plasminogen, Bif-1 etc.
Gap Junction as Electrical Synapse
We are looking into the role of connexins (Electrical Synapse) in synaptic plasticity using electrophysiological, e.g. bilayer and patch clamp, and spectroscopic methods, especially biochemical modifications and multichannel behavior.
Studies on Synthetic ion Channels.
We are interested in understanding the structure-function relationship of ion channels. In particular we are investigating the role of different domains of KvAP channel. KvAP is a potassium channel consisting of six trans-membrane domains. S6 is one of the pore domains assisting the transfer of potassium ions. We found S6 peptide itself can oligomerize on lipid membrane to form ion channel. In addition we are looking into the potential of other synthetic compounds, e.g. crown ether, to form ion channel.
Noise in Biological System
Biomolecules in a cell exist in dynamical state, hence associated with intrinsic noise. We are studying the intrinsic noise of bilayer membrane (BLM) and ion channels. BLM experimental data are being analyzed to characterize various noise patterns, which help us in understanding the dynamics of the system, especially the existence of Self Organized Criticality (SOC).
Collective Phenomena in Ion Channels
Collective phenomena have been observed in nature at various levels of organization. The phenomena lead to generation of exceptional properties of the system, which are otherwise not observable. The presence of ion channel clusters has been observed in various kinds of channels like Na, K, Ca Channels, VDAC, connexins etc. The collective behavior of the ion channels is being studied using Statistical Mechanical Models, e.g. ising Model, combined with multichannel experimental data.
Systems Biology of Memory formation
It is known that Long Term Potential (LTP), a prelude to memory formation, takes place through a complex metabolic network in a neuron. Presently we are investigating the role of Calcium flux in pre and postsynaptic neurons through systems biology approach using non linear differential equations.