females) were transferred to clean tubs lined with pine shavings. Any remaining animal in the litters was not used in these experiments. At P28, males and females were transferred, in same-sex groups of 4, to clean tubs. To prevent the stress associated with overcrowding, animals tested at adulthood were further separated in pairs at P60. Adolescents and adult animals had a mean body weight of 129.06 ± 12.5 g and 325.4 ± 80.23 g, respectively. Experimental procedures complied with the Guide for Care and Use of Laboratory Animals (NIH, Institute of Laboratory Animal Resources, 1996) and were also approved by the Institutional Animal Care and Use Committee within an AAALAC-accredited facility.
