Footshock-induced sensitization of the acoustic startle response in two strains of mice

It has been shown before that unconditioned footshocks can augment the acou stic startle response in rats. In the present study, male mice of two strai ns, C57BI/6N and BALB/c, were compared with regard to footshock-induced sen sitization of the acoustic startle response. Presentation of footshocks did not affect the acoustic startle response in C57BI/6N mice, while in contra st, footshock-induced sensitization was apparent in the BALB/c strain. Shoc ked C57B1/6N mice, but not BALB/c mice, displayed robust conditioning to th e startle context when re-tested the next day. These findings indicate that mice may exhibit footshock-induced sensitization of the acoustic startle r esponse, but that the effects of footshocks on the acoustic startle are str ain- and time-dependent. (C) 2001 Elsevier Science B.V. All rights reserved .