Scaling Approach to Find Order Parameters Quantifying the Effects of DopaminergicAgents on Unconditioned Motor Activity in Rats

摘要

A scaling approach was used to find order parameters quantifying the effects ofdopaminergic agents on unconditioned motor activity in rats. Three experiments were conducted in the Behavioral Pattern Monitor (BPM) to assess the effects of the D 1 agonist SKF-38393, the D 2 agonist quinpirole, and the interaction of the D, antagonists haloperidol with amphetamine or cocaine on the amount, the structure, and the unpredictability of micro-events of rat exploratory behavior. SKF-38393 (0.3, 1.0, 3.0, and 10.0 mg/kg) did not change the amount of motor behavior indicated by the temporal scaling exponent a, a descriptor of the local degree of acting, during a 60 min exposure in the BPM. However, SKF-38393 (3.0, and 10.0 mg/kg) significantly increased the spatial scaling exponent d, indicating an increased component of local circumscribed movements. Quinpirole (0.03, 0.1, 0.3, and 1.0 mg/kg) produced a biphasic dose response with respect to the amount of motor behavior, Low doses (0.03, 0.1) significantly decreased the local degree of acting, whereas a returned to control group levels for higher doses (0.3, 1.0 mg/kg). The change in activity was accompanied by a significant increase of local movements, i.e. d was increased for the lower doses.