A simple and effective method for building inexpensive infrared equipment used to monitor animal locomotion.

BACKGROUND: Infrared (IR) technology is a flexible and effective way of measuring animal locomotion. However, the cost of most commercial IR equipment can limit their availability. We have designed an inexpensive and effective replacement for commercial IR sensors that can be attached to enclosures to monitor animal locomotion. NEW METHOD: IR components were soldered to circuits connected to a single microcontroller. These IR components were housed inexpensively using plastic tubing and cork discs to further focus and extend detection of the IR beam. A standard personal computer recorded data from circuit boards connected to an inexpensive interface. This system may be used in a range of lighting conditions without requiring readjustment or recalibration. RESULTS: Validation of our equipment design was done with male Sprague Dawley rats treated with reserpine 22h prior to administration of saline or l-DOPA (125mg/kg). Data was collected in eight different measures: horizontal activity, immobile time, elevated activity, centre elevated activity, elevation time, elevation bout, and repeated and non-repeated movement while elevated. l-DOPA increased horizontal movement and all elevated activity excepting elevated movement and centre elevated movement, demonstrating selective drug effects. COMPARISON WITH EXISTING METHODS: The total cost of our complete IR system (US$517.45) was substantially less than the least expensive quote (US$19,666.90) obtained for a commercial IR system. CONCLUSIONS: We have successfully designed and constructed a flexible and inexpensive IR system to monitor at least eight measures of rodent locomotion at a significantly lesser cost than quoted by commercial suppliers.

The effect of quetiapine (Seroquel™) on conditioned place preference and elevated plus maze tests in rats when administered alone and in combination with (+)-amphetamine.

RATIONALE: Recent case reports describe recreational use of quetiapine and drug-seeking behaviour to obtain quetiapine, an atypical antipsychotic. OBJECTIVE: We examined the hypothesis that quetiapine (10, 20 or 40 mg/kg) alone or co-administered with (+)-amphetamine (0.25, 0.5, 0.75 or 2.0 mg/kg) will affect reward and/or decrease anxiety in rats, as measured by conditioned place preference (CPP) and elevated plus maze (EPM) test, respectively. RESULTS: Quetiapine (20 mg/kg) produced greater open arm time and entries in the EPM test compared to 10 and 40 mg/kg, and quetiapine (10 mg/kg) significantly increased open arm entries and time when co-administered with (+)-amphetamine (0.5 mg/kg) compared to (+)-amphetamine (0.5 mg/kg) alone, suggesting decreased anxiety. Quetiapine (10, 20 or 40 mg/kg) produced no CPP when administered alone; the lowest dose of quetiapine (10 mg/kg) reduced CPP produced by a low dose of (+)-amphetamine (0.25 mg/kg), but had no significant effect on CPP produced by a higher dose (0.5 mg/kg). DISCUSSION: The quetiapine-induced anxiolytic effect in the EPM might explain why humans are misusing quetiapine and combining it with (+)-amphetamine. It is possible that humans experience an anxiolytic effect of the combined drugs and relatively unaltered rewarding effects of (+)-amphetamine. The results shed some light on the question of why humans are abusing and misusing quetiapine, despite its dopamine (DA) D2 receptor antagonism; it will be the task of future studies to identify the pharmacological mechanism mediating this behaviour.