A comparison of buspirone and chlordiazepoxide in the shock-probe/burying test for anxiolytics

The effects of chlordiazepoxide (2.5-10.0 mg/kg IP) and buspirone (0.05-1.0 mg/kg SC) were compared by a "blind" observer using the shock-probe/burying test for anxiolytics. Both anxiolytic agents decreased rats' burying behavior toward the continuously electrified (2 mA) shock probe, and increased the number of probe-shocks rats received. These bidirectional, anxiolytic drug effects occurred at doses that did not affect the rats' general activity, and these anxiolytic effects generally increased as a function of drug dose. The relative potency of buspirone was substantially greater than that of chlordiazepoxide. These results contrast with those of Craft et al. and suggest that inappropriate methodology may have contributed to the inconsistencies in various results. In any case, under the present parameters, this "repeated shock"-probe test appears to have two advantages over the previous, "single shock" procedure. First, increases in probe-shocks and decreases in probe-burying provide two, concurrent measures of anxiolytic drug effects in the same setting. Second, nearly all subjects receive shock in the repeated shock procedure, compared to only 60-80% of subjects in the single shock procedure. Thus, both in terms of behavioral validity and simple economy, the repeated shock-probe procedure warrants further investigation as a selective test of anxiolytic agents.