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. Therefore, many 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:

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.


LabChart software is also suitable for evoked potential recordings that do NOT require waveform averaging or if more than two recording channels are required. The triggering option within LabChart is extremely useful to synchronize recordings with a stimulus, while the analog or digital outputs on the PowerLab may be used to control a third-party stimulator. The LabChart software can be used to identify the specific waveform components such as amplitude and latency.

LabChart Extensions are free for download from the website for existing LabChart users and they include:

  •  
  • Evoked Response (Mac Only): This extension analyzes physiological responses to a stimulus (evoked response experiments). A number of response parameters can be measured and logged to the Data Pad. This process can be automated to analyze a series of stimuli/response cycles. Parameters of the RMS-processed/integrated nerve signal can be measured that include value, latency, peak height, half-width, latency to peak, slope, height and area.
  • Peak Parameters (Win or Mac): Allows the user to determine a number of parameters for an individual peak. Parameters calculated include peak height, width, slope and various time parameters. It is useful for determining parameters of action potentials such as cardiac potentials, EPSP and IPSP.
  • Read Scope (Mac Only): Read Scope is a LabChart extension which allows LabChart for Mac to read Scope for Mac files directly.
  • The Shift Extension (Mac): Allows the sympathetic nerve recording to be shifted backward or forward in time.

Spike Histogram Module (Windows or Macintosh)
The MLS062/7 Spike Histogram Module for LabChart in combination with ADInstruments hardware provides the neuroscientist, in conjunction with our PowerLab systems, the ability to record and analyze extracellular spike data in real time and offline. Typical features include:

  • Provides easy to use spike discrimination and data analysis
  • Automatically indicates and examines changes in neural firing rate
  • Automatically determines the distribution of all interspike intervals
  • Performs autocorrelograms and crosscorrelograms analysis
Autocorrelogram and crosscorrelogram analyses are also available with the Spike Histogram Module for Macintosh. The Spike Histogram for Windows Module has the added feature of saving data in a .nex format for easy transfer to NeuroExplorer software for further analyses.


Scope
Scope software, supplied with PowerLab systems, provides powerful display, recording and analysis features to transform your computer into a two-channel storage oscilloscope, XY plotter or Power Spectrum (FFT) analyser. Scope is used commonly to measure any high-frequency signal that is time-locked to a stimulus such as action potentials and evoked responses. For analyzing Evoked Potentials, the Scope Software is recommended because it provides signal averaging functions that are necessary to extract the evoked response from background noise.

This software:

  • Provides the ability to record, display and analyze any high frequency signal that is time-locked to a stimulus
  • Synchronizes sweeps with recorded or built-in stimulation patterns
  • Provides a range of real-time and offline analysis features
  • Generates stimuli of differing intensities and waveform structures (i.e. single-pulse, multiple pulse, simple ramps) and control an external stimulator using the analog output on the front of the PowerLab.
Therefore, Scope is an ideal software program for recording any type of evoked potential because each successive stimulus and evoked potential may be recorded in a single sweep and the results of multiple sweeps may be superimposed or averaged to minimize signal noise and isolate the evoked potential. Scope is useful in signal averaging techniques to improve the signal-to-noise ratio and minimize artifacts induced by related events such as the blink-response. Features in Scope such as filtering and spectral analysis, may be used to identify oscillating potentials. The analog output of the PowerLab data acquisition system may be used to control a stroboscopic flash unit (with suitable inputs) for presentation of the light stimuli.

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:

Data Recording and Analysis
PowerLab data acquisition systems and LabChart/Scope software are ideal for sympathetic nerve recordings due to their ability to record at high sampling rates. They include:


Neuro Amplifier
The ML185 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. Only a single Neuro Amp EX may be connected to a single PowerLab. It is supplied:

Telemetry Dual Biopotential Foundation System
The ML880B106 Telemetry Dual Biopotential Foundation System is designed to record and analyze two biopotential signals such as ECG, EMG, EOG or EEG, as well as body temperature, wirelessly from individual compatible telemetry transmitters. However, transmitters are NOT included in this system and must be selected (number, type and size) and purchased separately.

Recommended transmitters are:


The system includes the ML319 TR Scheduler Pod and LabChart Scheduler Extension, allowing the user to schedule recording periods and record data sequentially from individual transmitters. Continuous 24 hour simultaneous charging/recording is also supported for small animal transmitters with appropriate wireless continuous power suppliers and subsidiary receivers

Telemetry SNA and Pressure Foundation System
The ML880B107 Telemetry SNA and Pressure Foundation System can be used to record and analyze Sympathetic Nerve Activity (SNA) in addition to intravascular or intralumen pressure in small and large animals, as well as body temperature, wirelessly from individual compatible telemetry transmitters. However, transmitters are NOT included in this system and must be selected (number, type and size) and purchased separately.

Recommended transmitters:


The system includes the ML319 TR Scheduler Pod and LabChart Scheduler Extension, allowing the user to schedule recording periods and record data sequentially from individual transmitters. Continuous 24 hour simultaneous charging/recording is also supported for small animal transmitters with appropriate wireless continuous power suppliers and subsidiary receivers

Accessories
The MLE1150 Telemetry Antenna Extension (TRAntX) for Telemetry Receivers consists of a four meter extension cable between receiver and antenna. The antenna extension enables the antenna to be placed closer to the animal in large animal cages, in situations where the receiver cannot be placed near cage

The MLE1140 Blood Pressure Starter Pack with instruments (TRStartBP) includes surgical instruments and components required to implant arterial transmitters in rats

The MLE1142 SNA Consumable Pack includes consumable items required to implant SNA transmitters in rats (excludes surgical instruments)

The SP0128 Silicone Elastomer for securing the SNA Telemetry probes to the nerve is a two-part silicone elastomer. It includes two 5 mL syringes and mixing tips.

Extracellular Recording System
ML870B70 Extracellular Recording System includes:


Preamplifiers and Accessories


Stimulators

 

 

Simvastatin normalizes automonic neural control in experimental heart failure
R U Pliquett, K G Cornish, J D Peuler and I H Zucker, Circulation, 2493-2498, 2003

Aging and the exercise pressor reflex in humans
T A Markel, J C Daley III, C S Hogeman, M D Herr, M H Khan, K S Gray, A R Kunselman and L I Sinoway, Circulation, 675-678, 2003

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.

Research Solutions
Education Solutions
Pharma Solutions
Citations Database
Top Solutions:
Site Feedback
X

Site Feedback

http://www.adinstruments.com/solutions/research/Sympathetic-Nerve-Activity/

* Denotes a required field
* Name
* E-Mail
* Operating System
* Web Browser

* Comments