Extracellular Field Recordings
Extracellular Field Recordings - Related Videos
03:04
Extracellular Recording of Electrical Activity in the Drosophila Central Nervous System
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2025
The video demonstrates the extracellular recording of neuronal activity from the central nervous system (CNS) of Drosophila larvae. The transected CNS is positioned in a recording chamber, and the electrical activity from a descending nerve is recorded to establish the baseline firing frequency. A test agent is then introduced, and the change in firing frequency is recorded to determine the agent's excitatory or inhibitory effect.
02:44
Recording of Local Field Potential in Mouse Hippocampal-Entorhinal Cortex Slices
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2025
The video demonstrates a procedure to record the local field potential (LFP) in mouse hippocampal-entorhinal cortex slices. Electrical stimulation is provided at the CA3 stratum radiatum of the hippocampus, which causes changes in the postsynaptic potential at the CA1 stratum pyramidale. The combined change in the membrane potential of CA1 neurons, termed the local field potential, is recorded.
03:00
Recording of Local Field Potential from Both Hemispheres of the Mouse Brain
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2025
This video demonstrates in vivo recording of local field potential (LFP) from bilateral M2 areas of the mouse brain. An anesthetized mouse is secured and prepared for the procedure. To record LFPs, insert microelectrodes into the target coordinates of the bilateral M2 areas, which are responsible for complex motor movements.
15:28
Extracellular Wire Tetrode Recording in Brain of Freely Walking Insects
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Cited by 24 •
2014
We previously developed a technique for implanting tetrode wires into the central complex of cockroach brains that allows us to monitor activity in individual units of tethered cockroaches. Here we present a modified version of that technique that allows us to also record brain activity in freely moving insects.
04:17
Concurrent Electroencephalographic and Local Field Potential Recordings in an Anesthetized Rat
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2025
This video demonstrates the procedure for concurrent recordings of co-localized electroencephalography (EEG) and local field potentials (LFPs) in an anesthetized rat. The process involves preparing the rat and attaching stimulating electrodes to its whisker pads. An EEG spider electrode is placed on the rat's skull for surface EEG measurements. At the same time, a multi-channel microelectrode is inserted into a specific brain region through a burr hole in the skull to record neural activity...
FAQs
The recorded voltage reflects the combined transmembrane currents produced by neurons near the electrode rather than the activity of one isolated cell. Because these currents sum in the surrounding tissue, coordinated activity across a local population can produce detectable voltage fluctuations. This population-level signal helps investigators examine how neural circuits operate collectively.
The signal contains activity at different time scales. Slower fluctuations appear as local field potentials and can reflect synaptic activity or network-wide dynamics, whereas faster changes correspond to action-potential signals when the recording uses suitable sampling. Examining these components together allows researchers to relate rapid neuronal events to broader circuit activity.
Synchronized activity makes contributions from nearby neurons align in time, strengthening detectable changes in the extracellular voltage. In contrast, less coordinated activity may contribute less clearly to the population signal. Measuring oscillations and synchrony therefore provides information about circuit organization, including how neural populations coordinate during behavior or stimulation.
Extracellular recordings avoid penetrating the cell membrane, so they do not directly measure the voltage across one neuron's membrane. Instead, they emphasize activity generated by nearby populations and can monitor multiple sites. This distinction makes the approach useful for studying network-level dynamics, while intracellular measurements are suited to the electrical behavior of individual cells.
An electrode is positioned near brain tissue, where it detects voltage fluctuations generated by surrounding neural activity. The recording can then be examined for slower local field potentials or faster action-potential signals, depending on the sampling used. Measurements from multiple sites or experimental conditions can reveal changes in circuit dynamics during behavior or stimulation.
These recordings can show how neural circuits process sensory information, change during learning, organize activity during sleep, or become altered in epilepsy and other neurological conditions. Researchers can evaluate network oscillations, synaptic activity, synchrony, and circuit changes during behavior or stimulation, making the method relevant to both normal neuroscience and disease-related investigations.