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Unveiling Hidden Neural Codes: SIMPL – A Scalable and Fast Approach for Optimizing Latent Variables and Tuning Curves in Neural Population Data

Dr. Rishabh Pathak
This research paper presents SIMPL (Scalable Iterative Maximization of Population-coded Latents), a novel, computationally efficient algorithm designed to refine the estimation of latent variables and tuning curves from neural population activity. Latent variables in neural data represent essential low-dimensional quantities encoding behavioral or cognitive states, which neuroscientists seek to identify to understand brain computations better. Background and Motivation Traditional approaches commonly assume the observed behavioral variable as the latent neural code. However, this assumption can lead to inaccuracies because neural activity sometimes encodes internal cognitive states differing subtly from observable behavior (e.g., anticipation, mental simulation). Existing latent variable models face challenges such as high computational cost, poor scalability to large datasets, limited expressiveness of tuning models, or difficulties interpreting complex neural network-based functio...
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Stages of Brain Development

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Dr. Rishabh Pathak

The stages of brain development encompass a series of critical processes that shape the structure and function of the brain from prenatal to postnatal periods. These stages include:


1. Cell Birth (Neurogenesis, Gliogenesis): The generation of neurons (neurogenesis) and glial cells (gliogenesis) begins early in prenatal development. Neurogenesis involves the formation of new neurons, while gliogenesis involves the production of glial cells that support and protect neurons.


2.   Cell Migration: Newly generated neurons migrate to their appropriate locations in the developing brain. This process is crucial for establishing the correct neural circuitry and organization of brain regions.


3.   Cell Differentiation: Neuronal cells undergo differentiation, where they acquire specific characteristics and functions based on their location and molecular signals. This process leads to the formation of distinct types of neurons and glial cells in the brain.


4.     Cell Maturation (Dendrite and Axon Growth): Neurons undergo maturation, characterized by the growth of dendrites (receiving branches) and axons (transmitting branches). Dendritic and axonal growth is essential for establishing connections between neurons and forming functional neural networks.


5. Synaptogenesis (Formation of Synapses): Synaptogenesis involves the formation of synapses, which are the connections between neurons where information is transmitted. This process is critical for establishing communication pathways in the brain and is essential for learning and memory.


6.     Cell Death and Synaptic Pruning: During development, there is a process of programmed cell death (apoptosis) that eliminates excess neurons and synapses. This pruning of unnecessary connections refines neural circuits and enhances the efficiency of information processing in the brain.


7.     Myelogenesis (Formation of Myelin): Myelogenesis involves the development of myelin, a fatty substance that insulates axons and speeds up neural transmission. Myelination occurs throughout development and is essential for the efficient functioning of neural circuits.

 

Understanding these stages of brain development is crucial for appreciating the complex and dynamic processes that shape the developing brain and lay the foundation for cognitive, emotional, and behavioral functions throughout life.

 

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