Startle Reflex – PPI

Sensorimotor deficits (PPI: Pre Pulse Inhibition), reactivity (ASR : Accoustic Startle Response)

Startle Reflex apparatus (PPI)

The Startle Reflex apparatus measures very sensitive variations of the force applied on the circular floor of the cage. Our apparatus analyzes the startle of the animal after the emission of a strong and brief sound.

We designed our Startle Reflex apparatus to be compatible with the coupling of other techniques, such as electrophysiology and optogenetics.

We offer different apparatus to study the Startle Reflex in Rats or Mice.



The Startle Reflex apparatus includes:

  • a ventilated and soundproof wooden cubicle,
  • a cylindric cage,
  • a circular platform on which stands the animal,
  • a very sensitive weight sensor, which measures in real time the force applied by the animal on the ground,
  • a sound generator, which may play sounds up to 110dB,
  • an option of electric shocks
  • a video control system
  • an infrared LED, which allows the synchronization of the video with the emission of the sounds.


The software on Windows allows managing 4 Startle Refelx apparatus simultaneously and independently. Our software allows:

  • a fine configuration of the sounds emitted: duration of prepulsen inter-pulse, pulse, level of the sounds up to 110dB,
  • playing sounds form the computer (WAV files),
  • creating randomized sequences of sounds,
  • recording millisecond per millisecond the value measured by the weight sensor in a specific file,
  • displaying the reflex responses on graphs in real time,
  • recording and datation of all the events,


This software displays the results in a Microsoft Excel compatible datasheet.


Coupling with Electrophysiology / Optogenetics

We propose solutions to couple the analysis of the Startle Reflex with electrophysiological recordings and optogenetic activation.


We propose:


We developed:

  • a rotation and rearing compensator, compatible with any optical commutator,
  • a device to activate lasers. This accessory sends electric signals up to 500Hz. The experimenter decides the exact moment according to clocks or behavioral outputs at which a customized train of pulses may be sent to the laser to specifically activate the targeted bunch of neurons.