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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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Excitation Inhibition Balance

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Dr. Rishabh Pathak

Excitation-inhibition balance refers to the equilibrium between excitatory and inhibitory neural activity in the brain. Maintaining a proper balance between excitation and inhibition is crucial for normal brain function, information processing, and neural network stability. Here are key points about excitation-inhibition balance:


1.   Excitatory Neurotransmission: Excitatory neurotransmitters, such as glutamate, promote the depolarization of neurons and the generation of action potentials. Excitatory signals facilitate neural communication and are essential for processes like learning, memory, and sensory perception.


2.  Inhibitory Neurotransmission: Inhibitory neurotransmitters, such as gamma-aminobutyric acid (GABA), counteract excitatory signals by hyperpolarizing neurons and reducing their likelihood of firing action potentials. Inhibition helps regulate neural activity, prevent excessive excitation, and maintain network stability.


3.     Role in Neural Circuits: The balance between excitation and inhibition is critical for the proper functioning of neural circuits. Imbalances, such as excessive excitation or reduced inhibition, can lead to hyperexcitability, seizures, cognitive deficits, and neurological disorders.


4.  Plasticity and Learning: Excitation-inhibition balance plays a key role in synaptic plasticity, the ability of synapses to strengthen or weaken in response to activity. Proper balance allows for adaptive changes in neural connectivity that underlie learning and memory. Disruptions in this balance can impair synaptic plasticity and cognitive function.


5.     Development and Critical Periods: Excitation-inhibition balance is particularly important during critical periods of brain development when neural circuits are forming and refining. Imbalances during these sensitive periods can have long-lasting effects on brain function and behavior.


6.  Clinical Implications: Dysregulation of excitation-inhibition balance has been implicated in various neurological and psychiatric disorders, including epilepsy, autism spectrum disorders, schizophrenia, and mood disorders. Therapeutic interventions targeting this balance, such as modulating neurotransmitter systems or enhancing inhibitory signaling, may offer potential treatments for these conditions.


In summary, excitation-inhibition balance is a fundamental aspect of neural function that ensures proper communication within the brain, supports synaptic plasticity and learning, and contributes to overall brain health. Maintaining this balance is essential for normal brain function and cognitive processes.

 

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