Sympathetic Nerve Activity

Overview:

The autonomic nervous system of mammals is involved with involuntary movements, actions and organ functions. This system can be further divided into the sympathetic motor system which is involved with quick responses such as “fight or flight” and parasympathetic motor system which is involved with slower relaxing responses. Sympathetic stimulation may result in excitatory, dilatatory and inhibitory effects of vessels, muscles and organs.  Sympathetic nerve activity (SNA) investigations have been made on humans and animals including cat, rabbit, rat and mice. The types of SNA recordings include:

  • Muscle Sympathetic Nerve Activity (MSNA)
  • Skin Sympathetic Nerve Activity (SSNA)
  • Renal Sympathetic Nerve Activity (RSNA)

Method:

Microelectroneurography or microneurography is commonly used for recording SNA in humans. A tungsten microelectrode inserted through the skin and into an accessible peripheral nerve, typically the common peroneal nerve at the fibular head or the median nerve near the wrist. The correct electrode position is confirmed by the characteristic response of neural activity to quick stimulation. Bursts of electrical activity (multi-unit or single-unit SNA) due to stimulation are then recorded.

SNA recordings on animals can be made in vivo or in vitro using a large variety of electrodes, depending on the method of recording. For example, the renal sympathetic nerve can be  isolated and placed on a bipolar electrode for recording nerve discharges in RSNA recording.

SNA recordings are extracellular recordings and therefore raw nerve signals need to be amplified using a preamplifier. A variety of systems offered by ADInstruments including the Neuro Amp EX, Extracellular Recording System or the Telemetry SNA Foundation System can be used to record SNA.

The Neuro Amp EX is an electrically isolated extracellular amplifier system, suitable for human and animal use and is used with the ADInstruments fully isolated Neuro Amp EX headstage. This headstage  solves the problems of noise associated with recording from high-impedance metal microelectrodes by providing pre-amplification and filtering of neural signals recorded close to the recording site. The Neuro Amp EX in conjunction with PowerLab, LabChart or Scope provides:

  • fully isolated high gain headstage
  • ultra low-noise (<2 mV rms) differential amplifier for extracellular recording from single cells or axons
  • 100 Hz – 5 kHz bandpass
  • accepts standard metal microelectrodes
  • certified for human use, ideal for microneurography
  • full electrical isolation from power-line circuitry to guarantee subject safety
  • software-controlled gain and low-pass, high-pass, notch and mains filters to remove unwanted signal frequencies for particular uses
  • audio output to listen to neurological signals

The features and benefits of the Telemetry SNA System include:

  • Record stress free, nerve activity and body temperature data from multiple animals
  • No special cages or barriers to record from multiple animals required as transmitters are programmed with independent transmission frequencies
  • Scheduling features allow the user to configure receiver settings, for data recording from each transmitter, which:
    • reduces file size
    • allows programming of recording times from seconds, minutes, hours, days or weeks
    • extends the recording life of the rechargeable battery
    • automates recording from multiple transmitters (up to 12 transmitters per system)


For more information, see the:

 

Software:

The LabChart Advantage:

(may require additional Modules and Extensions)

  • Sample up to 200,000 Hz in a single channel (up to 400,000 Hz aggregate) using the 35 series PowerLabs
  • Smoothing, Absolute Value, Integration and RMS Arithmetic calculations for quantification of neural activity
  • Scope View for spike-triggered averaging and the overlay of evoked responses
  • Spike Histogram Module for discrimination analysis of extracellular data
  • Peak Analysis Module for analysis of peak heights, half-widths, latency periods, population spike heights, rise times and areas

LabChart

LabChart software (for Windows and Macintosh) combines the familiar simplicity of a traditional strip chart recorder with the powerful analysis features of a digital acquisition system. LabChart software and a PowerLab data acquisition unit provide data integrity, easy selection of hardware settings, powerful online and offline analysis, procedure automation, seamless extraction of experimental data and flexible display options. Acquisition and analysis capabilities can be further increased with LabChart Extensions and LabChart Modules. LabChart Modules are available as part of LabChart Pro and LabChart Extensions are free for download from the website for existing LabChart users.

Spike Histogram Module

The Spike Histogram Module (Windows or Macintosh) in conjunction with our PowerLab systems provides the capability to record and analyze extracellular spike data in real-time and offline. 

Features and benefits include:

  • Provides easy to use spike discrimination and spike-sorting using easy to use amplitude and width discrimination, or semi-automated template matching
  • Performs auto-correlograms and cross-correlograms analysis
  • Saves data in a .nex format for easy transfer to NeuroExplorer software for further analyses (Windows only)
 

Peak Analysis Module

The Peak Analysis Module (Windows) automatically detects and analyses multiple, non-overlapping peaks in recorded waveforms.

Features and benefits include:

  • View automatically detected peaks with highlighted parameter markers, values and peak areas in the Peak Analysis View.
  • Log calculated peak parameters to a table and easily export parameters from the table into other programs.
  • Select from the default analysis settings available for general and specific signal types. For example, the Population Spike analysis detects and analyses extracellular evoked responses consisting of a spike population superimposed on an excitatory postsynaptic potential.
  • Customizable detection and calculation settings to suit your application or waveform.

Scope View

Scope View (LabChart Windows) provides the features of a digital oscilloscope to facilitate recording and viewing consecutive sweeps of data. These sweeps, or pages, can be overlaid and averaged within LabChart. The signal averaging functions are necessary to extract the evoked response from background noise.

There are several powerful features in Scope View that enhance analysis and display including:

  • Create pages or sweeps from Comments in Chart View in addition to block mode and Event Mode.
  • 3D Depth and Saturation Overlay feature in the Scope Overlay Options to help distinguish overlaid traces.
  • Alter the active trace and overlay trace colors.
  • Change the display background to black for better contrast.

GLP and 21 CFR Part 11

For those researchers working within a laboratory requiring GLP and 21 CFR Part 11 compliance the GLP Client and GLP Server are available for use with LabChart (Windows only) and PowerLab data acquisition systems. For more information, visit the Good Laboratory Practice application page or contact your nearest ADInstruments representative.

Hardware:

PowerLab Data Acquisition Systems

The PowerLab is a high-performance data acquisition unit capable of recording at speeds of up to 400,000 samples per second continuously to disk (aggregate). PowerLab units are compatible with instruments, signal conditioners and transducers supplied by ADInstruments, as well as many other third-party companies. In addition to standard single-ended BNC inputs, 4 differential Pod ports are also available for direct connection of Pod signal conditioners and appropriate transducers. Research PowerLab units include:

Research Systems

PL3508B73 Extracellular Recording System includes:

Signal Conditioners

The FE185 Neuro Amp EX is a low noise and high gain device which makes it suitable for all recording environments requiring a wide bandpass (100 Hz – 5 kHz) and a high signal to noise ratio. It provides a gain of 100x with a 10Hz High Pass filter. The cable shielding is directly connected to the casing, limiting the need for additional shielding at the input terminals. The device is certified safe for human connection with the supplied MLT185 Neuro Amp EX headstage. Also supplied are six male Amphenol connectors for customization of microelectrode adapters (microelectrodes are not supplied). Note: Only a single Neuro Amp EX may be connected to a single PowerLab.

Instruments

Extracellular Amplifiers

Note: With a suitable extracellular headstage an intracellular amplifier can also be used to make extracellular recordings.

Intracellular Amplifiers/Voltage Clamp

Stimulators

Transducers and Accessories

Electrode Holders

For the complete range of electrode holders click here:

  • ESW-F10N E Series Electrode Holder (Str, Ag Wire, 1.0 mm)
  • ESW-F10V E Series Electrode Holder (Str, Vent, Ag Wire, 1.0 mm)
  • ESW-F12N E Series Electrode Holder (Str, Ag Wire, 1.2 mm)
  • ESW-F12V E Series Electrode Holder (Str, Vent, Ag Wire, 1.2 mm)
  • ESW-F15N E Series Electrode Holder (Str, Ag Wire, 1.5 mm)
  • ESW-F15V E Series Electrode Holder (Str, Vent, Ag Wire, 1.5 mm)
  • ESW-F20N E Series Electrode Holder (Str, Ag Wire, 2.0 mm)
  • ESW-F20V E Series Electrode Holder (Str, Vent, Ag Wire, 2.0 mm)
  • ESW-M10P E Series Electrode Holder (Str, Port, Ag Wire, 1.0 mm)
  • ESW-M12P E Series Electrode Holder (Str, Port, Ag Wire, 1.2 mm)
  • ESW-M15P E Series Electrode Holder (Str, Port, Ag Wire, 1.5 mm)
  • ESW-M20P E Series Electrode Holder (Str, Port, Ag Wire, 2.0 mm)

Note: Selection is based on the outer diameter of user’s glass electrode

Extracellular Headstages

Cables

Interaction of transthoracic ultrasound and intravenous microbubbles woth cardiac mechanoreceptors
Xie F, Tsutsui J.M, Gao L, Zucker I.H and Porter T.R., Ultrasound in Medicine & Biology, 136-144, 2007

Chemoreflex and Metaboreflex Responses to Static Hypoxic Exercise in Aging Humans
Houssiere A, Najem B, Pathak A, Xhaet O, Naeije R and Borne P., Med & Sci in Sports and Exercise, 305-312, 2006

Exercise training prevents arterial bororeflex dysfunction in rats treated with central angiotensin II
Pan Y.-X, Gao L, Wang W.-Z, Zheng H, Liu D, Patel K.P, Zucker I.H and WAng W., Hypertension, 519-527, 2007

Citations Database



The material on this page is provided in good faith and believed accurate at the time of writing. No responsibility will be taken, or liability accepted, for damages arising from the use of information herein. Readers are urged to check with respective manufacturers the accuracy of all product related information.

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