1.  Experiment:  Compound Action Potential Recorded with a
     Differential Amplifier

In this experiment, recordings of compound action potentials are made from the frog sciatic nerve using a differential head stage amplifier.  Values measured from this preparation include:  amplitudes of action potentials as a function of stimulus strength, conduction velocity as a function of temperature, refractory period as a function of frequency of stimulation, and amplitude as a function of stimulus strength and duration.

These measurements are made with a DHS-300 differential head stage amplifier that is connected to one of the DIN8 inputs of the iWorx 214.  The DHS-300 can be used on a variety of tissues, with many different electrode types, and in locations with significant electronic noise.  The amplification of input channel on the iWorx 214 is programmed by the gain set resistor in the DIN8 connector of the DHS-300.  Alternate gains can be programmed by use of a C-DIN-M/F gain cable.
 

iWorx Browsing Area

Download print-disabled 
Compound Action Potential experiment
(PDF file).

Download high resolution, press optimized Compound Action Potential experiment
(PDF file). 

Download low resolution, screen optimized Compound Action Potential experiment  PDF file.
 

2.  Article:  DHS-300 Differential Head Stage Amplifier

The DHS-300 is a high common mode rejection (CMR), low noise differential amplifier designed for use with an iWorx 214 data recorder or an ETH-256 amplifier.  The DHS-300 can be placed close to the preparation, eliminating long lengths of wire between the electrodes and the amplifier.  These wires would act as a pick-up antenna for line current frequencies and other sources of electrical noise in the vicinity of the preparation.

Because of its high rejection of common mode noise, this head stage is the best solution for the extracellular recording of biopotentials in experimental

setups where it not possible for electronic noise to be reduced by a typical amplifier, Faraday cages, or shielding.

Learn more about the DHS-300 from this tech note.

3.  Article:  C-DIN-M/F Gain Cables

the transducer and the DIN 8 input of the iWorx data recorder or amplifier.

Learn more about the C-M-F-DIN gain cables from this Tech Note.

Special Offer to iWorx Users  
For a limited time, iWorx is offering its customers a 30% discount on purchase of the DHS-300 Differential Head Stage Amplifier and 50% discount on C-DIN-M/F Gain Cables.

Order Today!

4. Download: Settings for the Experiment Highlighted This
    Month and the Other Experiments Recently Published in the
    iWorx Newsletter

If you plan to use any of the experiments announced in recent editions of the iWorx Newsletter, you should obtain a copy of the settings group used to configure LabScribe for these experiments.  Once you have a copy of the settings group, drop the group into the LabScribe folder on your hard drive, and use the Settings menu to load the group and the list of experiments.
 

Download copies of the settings groups for the experiments announced since May 2004. 

5.  Web Resources

In this month’s experiment, the DHS-300 Differential Head Stage Amplifier was used to record action potentials from a frog sciatic nerve.  Learn about recording potentials from other types of organisms with an amplifier like the DHS-300 here.

On this page we have also accumulated a host of links to informative, external physiology Web sites and conveniently categorized them into major sub categories for easy reference.   

6.  LabsOnCD - A Requirement for Distance Learning
     Physiology Curriculum

LabsOnCD is an excellent tool for Distance Learning Physiology Courseware.  The browser-based CD includes 31 virtual animal and human lab experiments in neuromuscular, respiratory, and cardiovascular physiology.  The virtual labs are totally self-contained and require no additional lab manuals, courseware, or supplies.

Each lab includes a topical overview, background, equipment set-up and lab procedure, quiz questions, and an interactive LabPlayer that displays recorded data from real experiments and allows students to manipulate and record data just as they would in a "wet" lab.  Data can be captured and logged in an online Lab Journal that can be later copied to a new document or sent via email.  Labs are further enhanced with animations, diagrams, and video clips. 

The virtual labs can be accessed on a CD or from the Web and are designed specifically for student self-learning environments.

See more information, view an online demonstration, and request a free 30-day evaluation copy.

7.  Trade-in Specials

We have recently acquired a large supply of GRASS FT03 variable range Force transducers and P23id / P23xl reusable pressure transducers. Many of these items are BRAND NEW and are offered at up to 75% off original list price. Call for price and availability but hurry these will go fast. Also check with us about trade in allowances for your older Powerlab or Biopac equipment. See specials