Cognitive Sciences and Psychology
Title : | Stochastic resonance in the brain's GPS. How it helps encode and remember our trajectories through space |
Area of research : | Cognitive Sciences and Psychology |
Focus area : | Neuroscience |
Principal Investigator : | Dr. Collins Assisi, Indian Institute of Science Education and Research (IISER) Pune, Maharashtra |
Timeline Start Year : | 2024 |
Timeline End Year : | 2027 |
Contact info : | collins@iiserpune.ac.in |
Details
Executive Summary : | This proposal focuses on the role of grid cells in the hippocampal formation and entorhinal cortex in generating spatially circumscribed patterns of activity. These neurons are sequentially activated as an animal traverses space, allowing a unique sequence of activity to be mapped. Grid cells serve as a coordinate system for finding a path across a spatial field, even without external cues. Despite receiving sensory inputs from multiple modalities and being subject to stochastic inputs from extrinsic and intrinsic sources, grid cells maintain a grid-like spatial representation. An attractor network model of grid cells is proposed, connecting a network motif of excitatory stellate cells and inhibitory interneurons. This bistable system requires external perturbation to switch the activity of neurons. When driven by a 10 Hz oscillatory input, specific noise levels are needed to cause periodic switching between the network states. The presence of noise improves the system's response to weak or subthreshold inputs, such as theta oscillations. To construct a one-dimensional grid attractor network, the motifs are connected in a ring and introduced complementary asymmetries in the upper and lower rings. Interneurons receive oscillatory input and an additive noisy current, resulting in activity propagating along the ring only at specific noise levels, resembling a Brownian ratchet with a biased periodic potential.
The project will address how the form of noise affects system dynamics, how system parameters determine oscillation and noise-induced dynamics, and whether activity-dependent plasticity of inhibitory synaptic drive pushes the network into a regime where spatially periodic solutions are more robust. |
Total Budget (INR): | 6,60,000 |
Organizations involved