Extracellular Brain Activity
Extracellular Brain Activity - Related Videos
02:29
Microdialysis of Interstitial Fluid from a Mouse Brain to Isolate Extracellular Proteins
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2025
The video demonstrates the process of using a microdialysis probe to collect extracellular proteins from the interstitial fluid (ISF) of a mouse brain. A microdialysis probe, equipped with a high-molecular-weight cut-off semi-permeable membrane, is inserted into the brain of an anesthetized mouse via an implanted guide cannula. The probe, connected to pumps, allows a physiological buffer to perfuse the brain tissue and mix with the ISF. Proteins in the ISF diffuse across the semi-permeable...
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.
03:01
Characterizing Extracellular Space in a Brain Slice Using Ion-Selective and Iontophoresis Microelectrodes
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2025
This video demonstrates how to characterize the extracellular space in a brain slice by using ion-selective and iontophoresis microelectrodes to measure and compare electrical signals. This process helps determine the space's volume fraction and degree of twisting.
11:08
Double-barreled and Concentric Microelectrodes for Measurement of Extracellular Ion Signals in Brain Tissue
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Cited by 19 •
2015
We demonstrate the fabrication, calibration and properties of two types of ion-selective microelectrodes (double-barreled and concentric) for measurement of ion concentrations in brain tissue. These are then used in the mouse hippocampal slice preparation to show that excitatory activity changes both extracellular potassium and sodium concentrations.
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.
FAQs
The recorded voltage reflects transmembrane ionic currents and synaptic inputs that spread through the surrounding neural tissue. Because these sources influence nearby extracellular space, an electrode can capture activity generated by more than one cell. This enables researchers to examine coordinated neural signals rather than isolating only the electrical behavior of an individual neuron.
Action potentials appear as fast electrical events, whereas local field potentials change more slowly. These timescales provide complementary information: rapid signals help reveal individual neuronal firing within a recorded population, while slower fluctuations indicate broader patterns of network activity. Considering both types helps relate cellular events to coordinated brain states and functions.
Multi-electrode arrays and high-density probes sample activity from multiple sites, expanding the spatial view beyond a single recording location. This broader sampling supports comparisons across neurons and brain regions, making it possible to investigate coordinated population activity and map circuit relationships. The resulting measurements help connect local electrical events with larger-scale neural organization.
A study first detects voltage changes outside neural cells with electrodes, then distinguishes the fast and slow components of the recorded activity. Researchers can compare these signals with neural functions or states such as sensory processing, movement, and sleep. Using multiple recording sites further supports analysis of coordination across cells or brain regions.
Recordings can relate collective electrical patterns to distinct functional contexts, including sensory processing, movement, and sleep. This approach allows researchers to examine how neural populations coordinate during different brain states rather than focusing only on isolated cellular events. Comparing activity across these contexts can clarify how circuit-level dynamics accompany changing functions.
Multi-electrode arrays and high-density probes provide measurements from distributed neural sites, supporting circuit mapping and brain-computer interface research. The signals can be examined as population activity to identify relationships among regions or to connect neural dynamics with relevant functions. These applications also support investigation of how collective patterns emerge from individual neuronal activity.