The animal cage

     The animal cage is made up of black perspex (275 x 240 x 280h mm) with an upper access doors and an electrificable grid floor (stainless steel bars, 4 mm dia., spaced 10 mm); frontal panel & upper door is made of transparent perspex. The drinking tube is installed in one of the box sides; it is provided with a resistive detector for animal approaches to water and allows measuring of water consumption and water loss.

     Lick detection is established through the drinking water (80 ml), in such a way that only the consummatory behaviour is intended to be a response (this system has proved to be much more reliable than others, based on animal contact with the drinking tube, in which false responses due to contacts with the drinking tube without drink are possible).

The LE 3206 Control Unit

     The LE 3206 Control Unit provide full control over all the parameters necessaries to carry out the Vogel’s test, including those related with shock administration through a built–in shock generator.

     The LE 3206 is a microprocessor based instrument, with a 2 x 20 characters LCD and a mixed numeric & functions keyboard. Selecting the appropiate option in the controlling “menú”, it is possible to define the number of licks to be reached before a shock is given (up to 9999) and the total length of the experimental session (59:59 mm:ss).

     Once a START key is pressed, a new trial begins, with the parameters currently defined. Licks and shock counters and session timer are reset; the licks counter is increased with each new lick until reaching the pre-defined lick/shock ratio. A shock is then activated (intensity and duration must be selected separetely using the appropiate controls) and the shock counter increased. The session ends once the pre–programmed length time is reached (see below).

     Up to 99 trials can be stored permanently in the LE 3206 Control Unit and reviewed using the up/down arrow keys. In each trial, total number of licks and shock received durting the session are available.

     Additionally, responses (licks) and reinforcements (shock) are presented in back connectors, allowing for the use of the LE 6306 Cumulative Recorder.

     In the shock controlling section, the shock parameters can be set. Shock duration (from 0.1 to 10 s), intensity (from 0 to 2 mA) and the electronic scrambler velocity (on six poles) can be set through the frontal controls. The shock is delivered either manually or when an external start signal is provided by the control unit.