Jump to: navigation, search


Project name: The Spikerbox
Project summary: We are developing, using off-the-shelf components, low cost amplifiers and manipulators for experimenting with the nervous system of insects. Our goal is to increase the public's understanding of nervous system function through the development of low-cost tools. Currently, students need only a laptop with a line-in input to record the neural activity. We are developing our device to work with the XO to demonstrate extremely low-cost high-accessibility science.
Project goal: Bring neuroscience to everyone. One Cockroach Per Laptop (OCPL)!

Image:Activity-measure.svg We currently plan on using the Measure Activity.


Our good friend, and experimental prep, the humble American cockroach
The Spikerbox prototype version 2. This picture shows a wax dish containing a pinned cockroach leg is seen in the foreground, two cockroaches are in the clear tube, and an exposed SpikerBox is in the background.
Example recordings from neural discharges in the cockroach leg by blowing on the leg.
Gregory Gage
Pre-doctoral student in Biomedical Engineering, University of Michigan. Greg has a B.S. in Electrical Engineeringand a M.E. in Computer Engineering
+1 734 968-7570, gagegreg [at] backyardbrains [dot] com
Timothy Marzullo
Post-doctoral fellow in Neuroscience, University of Michigan. Tim has a Ph.D. in Neuroscience and has an extensive background in Biology.
+1 734 223-8133, tim [at] backyardbrains [dot] com

The Spikerbox

The current version of our SpikerBox is in the handmade printed circuit board stage (See photo below). It is still in development. The device consists of a small box with connections for two electrodes and an analog output.

The SpikerBox allows users to record the electrical discharges (or “spikes”) from the sensory nerve of a cockroach leg. The preparation for the experiment is simple enough that students can do it unassisted. The cockroach leg preparation is extremely robust and works every time.

  1. Cockroaches are first chilled in a refrigerator for 5-10 minutes to “anesthetize” them. Cold-blooded insects cannot generate body heat, so become immobile at low temperatures.
  2. The hind limb of the insect can be removed with scissors. The cockroach is still alive at this point, and limbs can be re-generated if the cockroach is still in the nymph stage.
  3. The leg is placed on the SpikerBox, and two sharp electrodes (modified sewing needles) are inserted into either end of the leg.
  4. The SpikerBox is then turned on. The neural signals are filtered and amplified, and students can listen to the neural activity through an internal speaker. The neural activity stems from the sensory neurons in the tiny wind-sensitive barbs on the leg of the cockroach. One can interact with the device by simply blowing on the leg and hearing a dramatic increase in the firing rate of spikes.

Experiments require data to be collected, and the neural activity can be displayed on a computer screen via a microphone port on a laptop. Currently, we plan on using the Measure Oscilloscope software for the OLPC to allow this information to be stored to the XO for further analysis. An example of recordings made on a MAC PC is on the right.

For more information and SpikerBox demos, please see the Backyard Brains homepage.

Development Updates

July 7, 2009

We received our two OLPCs about two weeks ago, and we are currently trying to improve the "Measure" application to work with our SpikerBox. Current builds of the software only allow us to record screenshots (see image on lower right). We are currently trying to fix this. However, if we go through the record application, doing audio only, we can record the spiking activity of the cockroach through the line-in input (listen to ogg link below)


It appears the Measure function is a bit buggy. We are using build 802. The data isn't recorded in a way we can manipulate.

A screenshot showing the spikes fed into the line-in port

To troubleshoot, using an iPod fed into the line-in input as a "sensor," spike waveforms were played through the sensor function of Measure. When the log was opened in the "write" function, the following appeared

OLPC output:

Session: 1,User: Timothy Marzullo,Interval: 30second,6975,5742

Session: 2,User: Timothy Marzullo,Interval: 1second,6843,6410,6929,7365,6450,7257,8965,7424'

Sampling rate does not appear high enough; 30 second recording only reveals two numbers; oddly 1 second recording reveals eight numbers.

Word on the street from the folks in Peru and Columbia working on the Measure application is that a patch improving Measure functionality may be available soon.

July 10th

Testing a new, simpler circuit design, we are happy to report we have seen real-time spikes of the XO! See photo below. the high amplitude transients are spikes from the discoid cockroach leg. As noted in July 7th update though, we can view the spikes, but we can't record them.

Our new circuit, recording from a cockroach leg, and fed into the XO
Our assistant Evan learning about the XO in our home workshop

Also, we have recruited a local high school student to learn about neuroscience and perhaps help us improve the XO measure function.

July 13th We have just received official notification that our exhibit will be part of the "Brain Awareness Event" at the Society for Neuroscience in Chicago]. We hope to have all prototypes fully operational battlestations!

August 8th We have been experimenting the Audacity program on the OLPC. A full write-up is available here.

August 12th The spike recordings work on the OLPC! We have issued a Call for Audacity to build Digital Oscilloscope features here.

Personal tools
  • Log in
  • Login with OpenID
About OLPC
About the laptop
About the tablet
OLPC wiki
In other languages