Skip to main content

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...
Post a Comment

Synaptic Deficits In Psychiatric Disorders

Image
Dr. Rishabh Pathak

Synaptic deficits play a significant role in the pathophysiology of various psychiatric disorders, contributing to the cognitive, emotional, and behavioral symptoms observed in these conditions. Here is an overview of synaptic deficits in key psychiatric disorders:


1.      Schizophrenia:

o  Synaptic Hypoconnectivity: Schizophrenia is associated with deficits in synaptic connectivity, including reduced synaptic density, altered dendritic spine morphology, and impaired synaptic plasticity in brain regions like the prefrontal cortex and hippocampus.

o Glutamatergic Dysfunction: Dysregulation of glutamatergic neurotransmission, particularly N-methyl-D-aspartate (NMDA) receptor hypofunction, contributes to synaptic deficits and disrupted neural circuitry in schizophrenia.

o  Synaptic Pruning Abnormalities: Aberrant synaptic pruning processes during neurodevelopment lead to excessive synaptic elimination, affecting neuronal connectivity and cognitive functions in individuals with schizophrenia.

2.     Depression:

o    Synaptic Atrophy: Depression is characterized by synaptic atrophy, reduced synaptic density, and impaired synaptic plasticity in regions such as the prefrontal cortex and hippocampus, impacting mood regulation and cognitive processing.

o    Neurotransmitter Imbalance: Dysregulation of monoaminergic neurotransmitters, such as serotonin and dopamine, can lead to synaptic deficits and altered synaptic transmission in depression.

oStress-Induced Changes: Chronic stress and elevated glucocorticoid levels associated with depression can disrupt synaptic structure and function, contributing to neuronal atrophy and synaptic loss.

3.     Bipolar Disorder:

o Synaptic Dysfunction: Bipolar disorder is characterized by synaptic dysfunction, including alterations in synaptic plasticity mechanisms, neurotransmitter release, and dendritic spine morphology in brain regions like the amygdala and prefrontal cortex.

o    Excitatory/Inhibitory Imbalance: Imbalance between excitatory and inhibitory synaptic transmission, involving disruptions in glutamatergic and gamma-aminobutyric acid (GABA)ergic signaling, is implicated in the pathophysiology of bipolar disorder.

o Circadian Rhythm Disruption: Dysregulation of circadian rhythms and clock genes can impact synaptic function and neuronal connectivity in individuals with bipolar disorder.

4.    Alzheimer's Disease:

o    Synaptic Loss: Alzheimer's disease is characterized by significant synaptic loss, particularly in regions crucial for memory and cognition, such as the hippocampus and neocortex.

o Amyloid and Tau Pathology: Accumulation of amyloid-beta plaques and tau tangles disrupt synaptic function, leading to synaptic degeneration and impaired neuronal communication in Alzheimer's disease.

o    Synaptic Plasticity Impairment: Disruption of synaptic plasticity mechanisms, including long-term potentiation (LTP) and long-term depression (LTD), contributes to cognitive decline and memory deficits in Alzheimer's disease.

Understanding the synaptic deficits in psychiatric disorders provides valuable insights into the underlying neurobiology of these conditions and offers potential targets for novel therapeutic interventions aimed at restoring synaptic function, improving neural connectivity, and alleviating symptoms associated with synaptic dysfunction.

 

Categories:

Comments

Post a Comment

Popular posts from this blog

Cell Maturation (Dendrite and Axon Growth)

Dr. Rishabh Pathak
Cell maturation, encompassing dendrite and axon growth, is a crucial stage of brain development where neurons undergo structural changes to establish connections and form functional neural circuits. Here is an overview of cell maturation in the context of dendrite and axon growth: 1.      Dendrite Growth : o     Definition : Dendrites are branched extensions of a neuron that receive signals from other neurons and transmit these signals to the cell body. o     Dendritic Arborization : During maturation, neurons extend and elaborate their dendritic arbors, increasing the surface area available for synaptic connections. o     Synaptic Integration : Dendritic growth is essential for forming synapses with other neurons, allowing for the integration of incoming signals and information processing. o     Activity-Dependent Plasticity : Dendritic growth can be influenced by neural activity and sensory experiences, sh...
Post a Comment
Read more

Amphiarthrodial or Cartilaginous Joints

Dr. Rishabh Pathak
Amphiarthrodial joints, also known as cartilaginous joints, are joints where the adjacent bones are connected by cartilage. These joints allow for limited movement and provide both stability and flexibility to the skeletal system. Here is an overview of amphiarthrodial or cartilaginous joints: Amphiarthrodial or Cartilaginous Joints: 1.     Structure : o     Cartilage : §   Amphiarthrodial joints are characterized by the presence of cartilage between the articulating surfaces of the bones. §   The cartilage can be hyaline cartilage or fibrocartilage, depending on the specific joint and its function. o     Lack of Joint Cavity : §   Similar to fibrous joints, cartilaginous joints do not have a synovial cavity, and the bones are held together by the cartilaginous tissue. 2.     Types : o     Synchondroses : §   Synchondroses are cartilaginous joints where the connecting material is hyaline carti...
Post a Comment
Read more

Ocular Artifacts

Dr. Rishabh Pathak
Ocular artifacts in EEG recordings are commonly caused by movements of the eyes, such as blinking, eye flutter, and eye movements associated with eye opening and closure. These artifacts can mimic epileptiform discharges and other EEG patterns, making them important to recognize and differentiate.  Nature of Ocular Artifacts : o    Ocular artifacts are primarily due to the movement of the electrical dipoles created by the eyes, particularly during activities like eye opening, closure, and directed gaze. o    The movement of these dipoles generates changing electrical fields that appear as EEG activity, with characteristics such as slow waves and spikes. o    Ocular artifacts are typically limited to the frontal region and do not extend into the central region of the brain. 2.      Differentiation from Epileptiform Discharges : o   Ocular artifacts can sometimes appear as bifrontal spike and slow wave complexes, resembling inter...
Post a Comment
Read more

Distinguishing Features of Electrode Artifacts

Dr. Rishabh Pathak
Electrode artifacts in EEG recordings can present with distinct features that differentiate them from genuine brain activity.  1.      Types of Electrode Artifacts : o Variety : Electrode artifacts encompass several types, including electrode pop, electrode contact, electrode/lead movement, perspiration artifacts, salt bridge artifacts, and movement artifacts. o Characteristics : Each type of electrode artifact exhibits specific waveform patterns and spatial distributions that aid in their identification and differentiation from true EEG signals. 2.    Electrode Pop : o Description : Electrode pop artifacts are characterized by paroxysmal, sharply contoured transients that interrupt the background EEG activity. o Localization : These artifacts typically involve only one electrode and lack a field indicating a gradual decrease in potential amplitude across the scalp. o Waveform : Electrode pop waveforms have a rapid rise and a slower fall compared to in...
Post a Comment
Read more

Cell Migration

Dr. Rishabh Pathak
Cell migration is a crucial stage of brain development where newly generated neurons move to their appropriate locations within the developing brain. Here is an overview of cell migration in the context of brain development: 1.      Definition : §   Cell migration refers to the process by which neurons and glial cells move from their site of origin to their final destination in the developing brain. §   Proper cell migration is essential for establishing the correct architecture and connectivity of the brain. 2.      Types of Cell Migration : §   Radial Migration : Radial migration involves neurons moving along radial glial fibers that span the developing brain. This type of migration is common in the cerebral cortex and helps neurons reach their appropriate cortical layers. §   Tangential Migration : Tangential migration occurs when neurons migrate horizontally across the developing brain. Interneurons, for example...
Post a Comment
Read more