HSE-HA Rodent Shocker
The HSE HA rodent shocker provides a reliable induction of seizure for testing anticonvulsant drugs.
- For testing anticonvulsant drugs
- For mice and rats
- Two types of electrodes are available: for eyes or ears
- Foot switch operation
- Security circuit for maximum users safety
Cerebral seizures, preferably in mice, are produced using constant sinusoidal alternating current to determine the effect of anticonvulsant drugs. For the reliable induction of seizures it is necessary to achieve satisfactory current flow.
Eye and Ear Electrodes
The electrodes are not included with the shocker and should be purchased separately (73-0107 or 73-0108). See Item Listing.
There are two types of shock stimulation electrodes for applying electric shock to mice and rats for testing anticonvulsant drugs: Eye electrodes and (especially in mice) ear electrodes.
Ear Electrodes
The ear electrodes offer the advantage that the course of the seizure can be observed more clearly, but have the disadvantage of a larger contact resistance. It is important that the electrodes are properly moistened! Normally the output circuit for constant current ensures the required stimulus response even for different impedances (a.c. resistances) of the animal on test.
The ear electrodes consist of two well-insulated nickel-plated crocodile clips. The contact points are formed by two chlorided silver discs 6 mm diameter and 1 mm thick.
This type of application requires a large shock energy since the contact resistance to the tissue is relatively high even when the skin is moistened. The advantage of this method is that the mice can be raised up by the electrodes so that the convulsions can be observed closely.
EyeElectrodes
The eye electrodes are bipolar. They are made from a flexible plastic ‘forceps’. Each forcep end has a stainless steel button covered by thin leather. The leather must be moistened with saline solution prior to use. Only a low shock energy is required since the eye is a highly conductive point.
Stimulation Current
The stimulation voltage is increased inside the unit until the selected stimulation current is produced. After application the current actually used can be indicated. The stimulus duration can also be pre-set and the elapsed time is monitored on a bargraph (line of LEDs).
Parameter Evaluated
The parameter evaluated is the percentage frequency of convulsions in a group of rodents at constant current.
Safety
The stimuli produced are not without danger to the operator; with an open output circuit (no animal connected to the unit) the stimulation voltage at stage 3 can reach its maximum of 750 Volt. In order to ensure operator safety the stimulus can only be triggered when two separate buttons ‘RELEASE’ (unblocking the inhibit circuit) and ‘START‘ are operated in sequence. In addition the stimulus output is floating and has no connection to ground. The current can therefore flow only between the two electrodes! As a further safety measure the output is automatically switched off if it is not connected to an object or if the contact between electrode and tissue is interrupted during stimulation.
To increase the stimulation current the CURRENT SETTING button is pressed and the control to the right of it rotated to obtain the required stimulation current. This additional measure has been introduced in order to remind the user of the increasing danger. Rubber gloves must be worn when working with the unit.
The output sockets are protected against contact. Only HSE shock electrodes with the original HSE safety banana plugs may be used.
Foot switch
A foot switch is supplied for triggering the stimulus; when working with the eye electrode one hand is used to hold the animal while the other holds the flexible forceps-shaped eye electrode.
Specifications | 73-0105 | 73-0106 | 73-3946 | 73-3947 |
---|---|---|---|---|
Stimulation Frequency | 60 Hz | 50 Hz | 50 Hz | 60 Hz |
Stimulus Duration | 0.1 sec to 9.9 sec in steps of 0.1 sec, selected after pressing a button, the selected time is indicated | 0.1 sec to 9.9 sec in steps of 0.1 sec, selected after pressing a button, the selected time is indicated | 0.1 sec to 9.9 sec in steps of 0.1 sec, selected after pressing a button, the selected time is indicated | 0.1 sec to 9.9 sec in steps of 0.1 sec, selected after pressing a button, the selected time is indicated |
Stimulus Energy | Up to 75 W | Up to 75 W | Up to 75 W | Up to 75 W |
Output | Constant current, fully floating | Constant current, fully floating | Constant current, fully floating | Constant current, fully floating |
Output Current Standard Version | 0 to 300 mA, 0 to 150 mA, 0 to 100 mA depending on maximum stimulation voltage selected, the setting is made on a 10-turn potentiometer and the selected value is shown on the digital display | 0 to 300 mA, 0 to 150 mA, 0 to 100 mA depending on maximum stimulation voltage selected, the setting is made on a 10-turn potentiometer and the selected value is shown on the digital display | N/A | N/A |
Output Current LC Version | N/A | N/A | 0 to 30mA and 0 to 20mA depending on selected voltage | 0 to 30mA and 0 to 20mA depending on selected voltage |
Limitation of Maximum Stimulation Voltage | 250 V, 500 V, 750 V in 3 steps, selected by button | 250 V, 500 V, 750 V in 3 steps, selected by button | 250 V, 500 V, 750 V in 3 steps, selected by button | 250 V, 500 V, 750 V in 3 steps, selected by button |
Digital Display | The selected stimulation current is indicated continuously in mA, the actual current applied is shown during application and can be called up later by pushing a button, the selected stimulation time is shown on pressing the TIME button, bargraph indicates the course of the stimulation time. | The selected stimulation current is indicated continuously in mA, the actual current applied is shown during application and can be called up later by pushing a button, the selected stimulation time is shown on pressing the TIME button, bargraph indicates the course of the stimulation time. | The selected stimulation current is indicated continuously in mA, the actual current applied is shown during application and can be called up later by pushing a button, the selected stimulation time is shown on pressing the TIME button, bargraph indicates the course of the stimulation time. | The selected stimulation current is indicated continuously in mA, the actual current applied is shown during application and can be called up later by pushing a button, the selected stimulation time is shown on pressing the TIME button, bargraph indicates the course of the stimulation time. |
Supply | 110 VAC, 60 Hz | 220 VAC, 50 Hz | 220 VAC, 50 Hz | 110 VAC, 60 Hz |
Dimensions, H x W x D | 150 x 260 x 360 mm (5.91 x 10.2 x 14.2 in) | 150 x 260 x 360 mm (5.91 x 10.2 x 14.2 in) | 150 x 260 x 360 mm (5.91 x 10.2 x 14.2 in) | 150 x 260 x 360 mm (5.91 x 10.2 x 14.2 in) |
Weight | 5 kg (11 lb) | 5 kg (11 lb) | 5 kg (11 lb) | 5 kg (11 lb) |