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

RB/E2F pathway regulates neurogenesis by modulating the composition of Neural Precursor population

Image
Dr. Rishabh Pathak

The Retinoblastoma (Rb)/E2F pathway plays a crucial role in regulating neurogenesis by modulating the composition of the neural precursor population. Here are key points regarding how the Rb/E2F pathway influences neurogenesis:


1.      Neural Precursor Cell Fate:

o    Regulation of Cell Cycle Exit: The Rb/E2F pathway controls the transition of neural precursor cells from proliferation to differentiation by promoting cell cycle exit. Activation of the Rb protein leads to the repression of E2F transcription factors, which are essential for driving cell cycle progression. By inhibiting E2F activity, Rb facilitates the exit of neural precursor cells from the cell cycle, allowing them to undergo differentiation.

o    Maintenance of Terminal Differentiation: Proper functioning of the Rb/E2F pathway is essential for maintaining terminal differentiation of neural precursor cells. Disruption of Rb-mediated regulation can result in defects in neuronal maturation and migration, leading to abnormalities in the composition of the neural precursor population.

2.     DLX Transcription Factors:

o    Regulation of DLX Genes: The Rb/E2F pathway modulates the expression of DLX homeodomain genes, particularly Dlx2, which are critical for ventral telencephalic development and the generation of specific interneuron subtypes. Rb interacts with regulatory regions of the Dlx1/Dlx2 locus, including enhancers and promoters, to control DLX gene expression. E2F functional sites act as repressor elements in these regions, influencing the transcriptional activity of DLX genes.

o  Role in Neuronal Differentiation: By directly regulating DLX gene expression, the Rb/E2F pathway contributes to the differentiation and specification of neural precursor cells into distinct neuronal subtypes. Dysregulation of DLX genes due to Rb pathway dysfunction can impact the diversity and maturation of the neural precursor population.

3.     Cell Cycle Dynamics:

o Coordination of Proliferation and Differentiation: The Rb/E2F pathway coordinates the balance between proliferation and differentiation in neural precursor cells. By controlling the expression of key transcription factors and cell cycle regulators, Rb ensures that neural precursors appropriately exit the cell cycle and commit to neuronal differentiation pathways.

o Temporal Progression of Neurodevelopment: Through its interactions with downstream targets such as Znf238, the Rb/E2F pathway orchestrates the temporal progression of neurodevelopment. Negative feedback loops mediated by Rb/E2F-regulated factors help consolidate cell cycle exit and regulate the migration and differentiation of newborn cortical neurons.

In summary, the Rb/E2F pathway plays a pivotal role in regulating neurogenesis by modulating the composition of the neural precursor population. By controlling cell cycle exit, maintaining terminal differentiation, regulating DLX transcription factors, and coordinating proliferation and differentiation processes, the Rb/E2F pathway influences the generation and maturation of neurons during brain development. Understanding the mechanisms by which the Rb/E2F pathway shapes the neural precursor population provides insights into neurodevelopmental processes and potential therapeutic targets for neurodevelopmental disorders.

 

Categories:

Comments

Post a Comment

Popular posts from this blog

Review Settings of EEG

Dr. Rishabh Pathak
The review settings of an EEG recording refer to the parameters that can be adjusted to optimize the visualization and interpretation of electrical brain activity. Here is an overview of the key review settings in EEG analysis: 1.       Amplification (Gain/Sensitivity) : o Definition : Amplification, also known as gain or sensitivity, determines how much the electrical signals from the brain are amplified before being displayed on the EEG recording. o Measurement : Typically measured in microvolts per millimeter (μV/mm). o Impact : Adjusting the amplification setting can affect the visibility of high-amplitude and low-amplitude activity. High-amplitude activity may require vertical compression to fit within the display range, while low-amplitude activity may require lower sensitivity settings for better visualization. 2.      Frequency Filtering : o Bandpass : The frequency range within which EEG signals are analyzed. Common settings include ...
Post a Comment
Read more

Cancellous Bone

Dr. Rishabh Pathak
Cancellous bone, also known as trabecular or spongy bone, is the other main type of bone tissue found in the human skeleton alongside cortical bone. Cancellous bone has a porous and lattice-like structure, providing flexibility, shock absorption, and a site for hematopoiesis (blood cell formation). Here are key features and characteristics of cancellous bone: 1.     Structure : o     Trabeculae : Cancellous bone is composed of a network of thin, bony trabeculae that form an interconnected lattice structure. o     Bone Marrow : The spaces between trabeculae contain red bone marrow, which is involved in the production of blood cells (hematopoiesis). o     Less Compact : Cancellous bone is less dense and compact than cortical bone, with a higher surface area-to-volume ratio. 2.     Composition : o     Trabecular Bone : The trabeculae are made up of lamellae, osteocytes, and canaliculi similar to corti...
Post a Comment
Read more

Anatomical Classification of Bones

Dr. Rishabh Pathak
Bones in the human body can be classified into five main anatomical categories based on their shape and structure. These classifications provide insights into the functions and characteristics of different bone types. Here are the five anatomical classifications of bones: 1.     Long Bones : o     Description : Long bones are characterized by their elongated shape, with a shaft (diaphysis) and two expanded ends (epiphyses). o     Examples : Femur, humerus, radius, ulna, tibia, fibula. o     Function : Long bones provide support, leverage, and mobility. They are essential for body movement and weight-bearing activities. 2.     Short Bones : o     Description : Short bones are roughly cube-shaped or have a similar length and width, providing stability and support. o     Examples : Carpals (wrist bones), tarsals (ankle bones). o     Function : Short bones contribute to we...
Post a Comment
Read more

Translocation, Retention and Potential Neurological Lesion in The Brain and Following Nanoparticle Exposure

Dr. Rishabh Pathak
Translocation, retention, and potential neurological lesions in the brain following nanoparticle exposure are important considerations in nanotoxicology and neurotoxicology research. Here are some key points regarding the impact of nanoparticle exposure on the brain: 1.       Translocation to the Brain : o Nanoparticles can enter the brain through various routes, including systemic circulation, olfactory nerve pathways, and disrupted blood-brain barrier (BBB) integrity. o Factors such as nanoparticle size, surface properties, shape, and surface modifications influence their ability to cross biological barriers and reach the brain parenchyma. 2.      Retention in the Brain : o Once nanoparticles translocate to the brain, they may exhibit different retention times depending on their physicochemical properties and interactions with brain cells. o Nanoparticles can accumulate in specific brain regions, such as the olfactory bulb, hippocampus, and...
Post a Comment
Read more

Unrestricted Sampling

Dr. Rishabh Pathak
Unrestricted sampling, also known as simple random sampling, is a fundamental sampling technique where each element in the population has an equal and independent chance of being selected for the sample. In unrestricted sampling: 1.     Equal Probability of Selection : §   In simple random sampling, every element in the population has an equal probability of being chosen for the sample. This ensures that each unit is selected independently of other units, without any bias towards specific elements. 2.     Random Selection : §   The selection of sample elements is done randomly, without any systematic pattern or predetermined order. This randomness is essential to ensure that the sample is representative of the population and to minimize selection bias. 3.     Independence of Selection : §   Each selection is made independently of previous selections, meaning that the inclusion or exclusion of one element does not influence the ...
Post a Comment
Read more