Research Areas

Whole cell ionic current and single ion channel biophysics, plasticity and pharmacology

Different versions of the patch-clamp technique as illustrated schematically in the right panel are utilized to understand the properties of ion channels expressed in cell lines. Transient as well as stable transfection of ion channel genes of interest are carried out using molecular biology and tissue culture techniques. The properties of expressed ion channels are analyzed subsequently. The right panel (a) shows studies on single voltage gate Na channel where a molecular memory mechanism has been established, and the kinetic analysis was done using HMM. The single channel activity of a leak potassium channel is shown in b. The superimposed red lines are the fit of the raw traces by model generated by QuB suite.

(Courtesy: Tapan Kumar Nayak)

Neuronal function and neuron-astrocyte interaction using autaptic, neuronal and astrocyte primary cultures

Neuronal function and neuron-astrocyte interaction using autaptic, mixed neuronal cultures and astrocyte cultures along with combined patch-clamp and imaging techniques are used to understand the fundamental properties of neurons, astrocytes, neuron-astrocyte and astrocyte-neuron interactions in experimental situations that try to understand physiological and pathological conditions in the brain

(Courtesy: Padmashri Ragunathan, Shilpa Rao)

Ca-dynamics in neurons using acute and organotypic brain slice experiments

Schematic diagram of combined entorhinal-hippocampal brain slice, where location of subiculum (SUB), pre subiculum (Pre SUB), para subiculum (Para SUB) are indicated. Electrical activity of individual subicular pyramidal neurons are studied using the patch clamp technique. Calcium dynamics is followed by incorporating the Ca dye Oregon green Bapta-1 in the pipette. The morphology of the neuron is constructed by incorporating biocytin in the pipette solution. The structure of the neuron is reconstructed using confocal microscopy and Neurolucida. Shown on the left is a subicular pyramidal neuron with burst firing induced by a solution composition that makes the neurons epileptogenic.

(courtesy: Kalyan V Srinivas)

Neural networks, Network topology and Pharmacology

Neurons are cultured on multi-electrode array probes. Extracellular field potentials from 64 electrodes are amplified and recorded. The signals are converted into spike data. Cross-covariance analysis is applied to the spike data and information about network topology obtained. Studies show that neuronal cultures do not show scale-free network topology. In experimental epileptic conditions the network topology changes.

(Courtesy: Kalyan V Srinivas)

Backpropagating action potentials, Ca dynamics in dendritic spines and co-incident detection using organotypic brain slice culture

Spines in dendrites are important sites of synaptic integration. Experiments are being standardized to record Ca changes in spines of dendrites in CA3 pyramidal neurons in organotypic brain slice cultures with a view to understand local Ca handling mechanisms. The experiments require combined patch-clamp and confocal experimentation.

(Courtesy: Anurag Pandey)

The Future... Using the intelligence of neural networks in a dish