THE ACOUSTIC STARTLE RESPONSE IN INBRED ROMAN HIGH-AVOIDANCE AND LOW-AVOIDANCE RATS

To investigate the emotional reactions of two rat strains selectively bred for good and poor two-way avoidance acquisition (RHA/Verh and RLA /Verh), male animals of both strains were tested in an acoustic startl e response test. They received 40 acoustic stimuli followed by 10 elec tric foot shocks and another 30 acoustic stimuli. RLA/Verh rats showed a significantly higher startle response compared to RHA/Verh animals, indicating a stronger emotional reaction to acoustic stimuli. In addi tion, the former showed a stronger response to foot shocks. Combined w ith earlier findings, we conclude that selection for two-way avoidance learning does not result in cognitive defects in the RLA/Verh strain but, rather, in stronger emotional reactions to fearful stimuli.