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LEGS CNRS
UMR PISC
AgroParisTech
INRA
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TasteProbe is the result of an active collaboration of several years
between our lab and
SYNTECH. It was designed to compensate the electrical offset of a taste hair (100-400
mV) so that extracellularly recorded spikes (100 µV-2 mV) can be amplified without
filtering. This compensation occurs during the first ms of the initial contact and is
maintained throughout the recording.
Schematics |
Principle :
The signal is continuously monitored by the input amplifier. In its
initial state, the electronic switch is closed. In this state, the
incoming signal is duplicated on two paths which lead to the input of the
2 entries of a difference amplifier. Since the two signals are equal, the
output signal is zero.
On contact with a taste hair, a large offset is seen by the contact
detector. A delay circuit opens the electronic switch after a delay
and during 2-5 seconds. During this time, the difference amplifier sees
the incoming signal (A channel) minus the signal stored in the capacitor
(B channel), thus compensating the voltage offset. |
Record sample |
Spikes recorded |
More informations can be found in this paper:
- Marion-Poll F., Van der Pers J., 1996 - Un-filtered recordings from
insect taste sensilla. Entomologia Experimentalis et Applicata 80: 113-115.
Syntech is now releasing of a new generation of
Tasteprobe, entirely digital. A cool feature of this system is that it can run
as a stand-alone amplifier, or it can be used as a probe for an
amplifier.
return to home page; last edited: novembre 18, 2008.
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