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Energy Manifold Natural Gradient Descent: From Riemannian Optimization to Modern Neuroscience, NeuroAI and Quantum Physics

Dr. Rishabh Pathak
When Geometry, Energy, Artificial Intelligence and Neuroscience Converge Modern Artificial Intelligence is rapidly moving beyond the idea that learning simply means minimizing an error function. Increasingly, researchers are asking a deeper question: what is the structure of the space in which learning takes place? This question becomes particularly important when the system being modelled is constrained, nonlinear, dynamic, or governed by physical principles. A recent work titled “Energy Manifold Natural Gradient Descent: Riemannian Optimization for Neural PDE Solvers” , by Zhangyong Liang and Huanhuan Gao, introduces Energy Manifold Natural Gradient Descent (EMNGD) , a mathematical framework that extends energy-based natural-gradient optimization from unconstrained Euclidean parameter spaces to constrained Riemannian parameter manifolds . At its core, the framework proposes a simple but powerful principle: An optimization algorithm should not only determine how to reduce error; it sh...
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Glutamate. From its isolation to neurotransmitter function

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Dr. Rishabh Pathak

The journey of glutamate from its isolation to its recognition as a key neurotransmitter in the brain is a fascinating story that spans several decades of scientific discovery. Here is an overview of the milestones in the history of glutamate, highlighting its isolation and eventual identification as a major neurotransmitter:


1.      Isolation of Glutamate:

o    Glutamate, an amino acid, was first isolated in 1866 by the German chemist Karl Heinrich Ritthausen from wheat gluten.

o    In the early 20th century, researchers identified glutamate as a component of protein-rich foods and a building block of proteins in the body.

2.     Identification as a Neurotransmitter:

o    In the 1950s and 1960s, researchers began to investigate the role of glutamate in the central nervous system.

o    In 1957, Daniel McGeer and John McGeer discovered that glutamate is present in high concentrations in the brain and spinal cord.

o    In the 1960s, researchers such as John Curtis Watkins and Edward Roberts demonstrated that glutamate acts as an excitatory neurotransmitter in the brain.

o    In the 1970s, the concept of glutamate as a major neurotransmitter in the brain gained widespread acceptance, particularly in the field of neuroscience.

3.     Glutamate Receptors:

o    In the 1980s and 1990s, researchers identified and characterized several types of glutamate receptors in the brain, including NMDA (N-methyl-D-aspartate), AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid), and kainate receptors.

o    These receptors play crucial roles in synaptic transmission, plasticity, and neuronal communication.

4.    Excitatory Neurotransmission:

oGlutamate is now recognized as the primary excitatory neurotransmitter in the central nervous system, responsible for fast synaptic transmission and neuronal signaling.

o    It plays a key role in processes such as learning, memory, and motor function.

5.     Neurological Implications:

o    Dysregulation of glutamate signaling has been implicated in various neurological disorders, including epilepsy, stroke, Alzheimer's disease, and Parkinson's disease.

o    Research continues to explore the role of glutamate in brain function and its potential as a target for therapeutic interventions in neurological and psychiatric conditions.

Overall, the journey of glutamate from its isolation as an amino acid to its recognition as a major neurotransmitter in the brain represents a significant advancement in our understanding of brain function and neurological disorders.

 

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