Population Spikes
Population Spikes - Related Videos
08:48
Optical Recording of Suprathreshold Neural Activity with Single-cell and Single-spike Resolution
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Cited by 1 •
2012
Understanding the function of the vertebrate central nervous system requires recordings from many neurons because cortical function arises on the level of populations of neurons. Here we describe an optical method to record suprathreshold neural activity with single-cell and single-spike resolution, dithered random-access scanning. This method records somatic fluorescence calcium signals from up to 100 neurons with high temporal resolution. A maximum-likelihood algorithm deconvolves the...
02:19
Triggering a Closed-Loop Stimulation by Neuron Spiking Activity
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2025
This video demonstrates the operation of closed-loop stimulation in a rat with a surgically implanted device to record neural activity. Neuronal signals are first recorded and analyzed. Template waveforms are then uploaded, and parameters are defined to trigger closed-loop stimulation.
02:46
Visualizing Dose-Dependent Spike Protein Uptake with Quantum Dot Conjugates
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2026
Source: Tran, B. N., et. al. High-throughput Confocal Imaging of Quantum Dot-Conjugated SARS-CoV-2 Spike Trimers to Track Binding and Endocytosis in HEK293T Cells. J. Vis. Exp. (2022)This video demonstrates the use of quantum dot–conjugated spike protein (QD-Spike) to visualize dose-dependent viral entry in ACE2-GFP–expressing cells. Confocal imaging captures the internalization of QD-Spike via receptor-mediated endocytosis, modeling early coronavirus entry.
08:29
Averaging of Viral Envelope Glycoprotein Spikes from Electron Cryotomography Reconstructions using Jsubtomo
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Cited by 23 •
2014
An approach is presented for determining structures of viral membrane glycoprotein complexes using a combination of electron cryo-tomography and sub-tomogram averaging with the computational package Jsubtomo.
14:47
Population Growth - Student Protocol
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2019
Exponential Population Growth Model ExpandNOTE: In these experiments you will use computer software to simulate different types of growth models. HYPOTHESES: The experimental hypothesis might be that if we increase either R, the reproductive rate or the initial population size, NT, that this will increase the population size after 10 generations in an exponential growth model compared to unmanipulated control populations. The null hypothesis may be that populations of different R and initial...
FAQs
The strength of a population spike depends on how many neurons are recruited and how closely their firing is synchronized. Excitatory input must drive a sufficient fraction of cells to threshold; when recruitment becomes coordinated, their extracellular contributions combine into a larger measurable signal. This links single-neuron threshold events with circuit-level activity.
The threshold condition determines whether excitatory input produces limited cellular activity or a coordinated network response. If enough neurons reach threshold together, their electrical contributions become detectable as a prominent compound signal. Consequently, changes in excitatory drive or neuronal excitability can alter whether a population spike appears and how strongly it is expressed.
Amplitude provides information about the magnitude of coordinated neuronal recruitment, whereas timing indicates when the network response occurs relative to the driving input. Examining both features helps researchers distinguish changes in excitability from alterations in signal transmission or coordination. These measurements can therefore expose different forms of network dysfunction even when activity remains detectable.
A single-neuron measurement describes the electrical behavior of one cell, while a population spike reflects the combined extracellular contribution of many neurons firing in a coordinated manner. The compound signal therefore emphasizes network-level organization rather than isolated cellular events. This distinction makes it useful for connecting cellular excitability with circuit-wide responses.
Field-potential recording measures the extracellular electrical signal produced by coordinated activity in a neural circuit. Researchers can then evaluate features such as population-spike amplitude and timing to assess how strongly and consistently neurons respond. Because the measurement captures compound activity, it supports analysis of network excitability, synaptic integration, and transmission within the recorded preparation.
In hippocampal circuits, population spikes provide a way to examine how excitatory input is integrated across groups of neurons and converted into coordinated electrical output. Their amplitude and timing can reveal changes in circuit responsiveness and signal transmission. This makes them useful for studying how hippocampal network function changes under different experimental conditions.
Population-spike measurements can change when neuronal excitability, synaptic integration, or signal transmission is modified. The overview identifies learning, epilepsy, neurodegeneration, and pharmacological manipulation as contexts in which amplitude or timing may shift. Interpreting those changes requires relating the measured signal to whether coordination, responsiveness, or transmission within the circuit has been affected.
These signals help investigators connect cellular activity with coordinated brain responses. They can be used to evaluate network function during learning, examine altered activity associated with epilepsy or neurodegeneration, and assess the effects of pharmacological manipulation. Comparing population-spike amplitude and timing across conditions provides measurable evidence for changes in neuronal excitability and circuit communication.