Local field potential

Spike triggered averages

Local field potential (LFP) refers to the electric potential recorded in the extracellular space of neural tissue. LFPs are generated by the summed electric currents flowing from multiple nearby neurons, primarily reflecting synaptic activity and other slower ionic processes. They are a crucial tool in neuroscience for understanding the collective behavior of neurons in a specific region of the brain.

Recording Techniques

LFPs are typically recorded using microelectrode arrays or electrocorticography (ECoG) grids. These devices are implanted in or on the surface of the brain and can measure the electrical activity from a population of neurons. The signals are then amplified and filtered to isolate the LFPs from other types of neural signals, such as action potentials.

Characteristics

LFPs are characterized by their frequency content, which can range from less than 1 Hz to several hundred Hz. Different frequency bands are associated with different types of neural activity:

• Delta (1-4 Hz)
• Theta (4-8 Hz)
• Alpha (8-12 Hz)
• Beta (12-30 Hz)
• Gamma (30-100 Hz)

Applications

LFPs are used in various applications within neuroscience research and clinical practice:

• Brain-Computer Interfaces (BCIs): LFPs can be used to control external devices, providing a communication pathway for individuals with severe motor disabilities.
• Epilepsy Monitoring: LFPs are used to identify and localize seizure activity in patients with epilepsy.
• Cognitive Neuroscience: Researchers study LFPs to understand the neural basis of cognitive processes such as memory, attention, and decision-making.

Advantages and Limitations

Advantages

• Spatial Resolution: LFPs provide better spatial resolution compared to non-invasive techniques like electroencephalography (EEG).
• Temporal Resolution: LFPs offer high temporal resolution, allowing researchers to study rapid neural dynamics.

Limitations

• Invasiveness: Recording LFPs requires surgical implantation of electrodes, which carries risks and is not suitable for all patients.
• Signal Interpretation: LFPs represent the summed activity of many neurons, making it challenging to attribute the signal to specific neural sources.

Related Pages

• Neural oscillation
• Electrophysiology
• Neurophysiology
• Microelectrode array
• Electrocorticography
• Brain-computer interface
• Epilepsy

See Also

• Action potential
• Synaptic transmission
• Neural coding
• Neural network