This data set, its source, and the methods used to generate it, are described in
The data set is also used in
When referencing this material, please include at least one of the citations above, and also include the standard citation for PhysioNet:
The SGAMP database contains single-unit neuronal recordings of North Atlantic squid (Loligo pealei) giant axons in response to stimulus currents. The membrane potential and stimulus current are given for a total of 170 trials across 8 different axons.
The applied stimulus current profiles can be divided into two groups: Stochastically summated polysynaptic currents (PSCs), and individual current pulses. Refer to the original publication for technical details, and see the
Recording-Info.ods spreadsheet for information about each trial. In addition, the
Irms file contains the root mean squared stimulus current values in uA/cm2. This only applies to stochastic current records when the stimulation is on; current pulse records are marked 'PULSE'.
The files in the raw directory contain the original raw values captured by the DATAQ Instruments capturing device (translated into MIT format). Both channels are given in volts, and have not been calibrated or translated into their physical units. In order to convert the raw recorded values into physical units:
- For the membrane potential channel (1), multiply the values by 0.1 to remove the instrumentation gain. This gives the membrane potential in volts.
- For the stimulus current channel (2), apply the physical unit conversion, 1V = 5uA/cm2 to get the stimulus current in uA/cm2. Note that current recordings may have a DC offset due to the recording instrumentation, which does not reflect an offset of applied current. When the stimulation current is off, the baseline should be zero.
File names are in the form aXtY, where X is the axon number and Y is the trial number for that axon. Each record lasts in the order of several seconds and is sampled at 125KHz.
Name Last modified Size Description
Parent Directory - Irms.txt 2016-04-16 16:19 2.6K MD5SUMS 2016-04-16 16:19 224 RECORDS 2016-04-16 16:19 1.7K list of record names Recording-Info.ods 2016-04-16 16:19 54K SHA256SUMS 2016-04-16 16:19 384 SHA1SUMS 2016-04-16 16:19 264 raw/ 2016-04-16 16:20 - DOI 2016-04-26 14:07 20
If you would like help understanding, using, or downloading content, please see our Frequently Asked Questions.
If you have any comments, feedback, or particular questions regarding this page, please send them to the webmaster.
Comments and issues can also be raised on PhysioNet's GitHub page.
Updated Friday, 28 October 2016 at 16:58 EDT