Long evans blue spruce rats

A total of 64 adult female and male Long-Evans and Wistar rats were used in this study. Long-Evans Blue Spruce rats (male, n = 16; female, n = 16) were obtained from Envigo (Indianapolis, IN) and weighed 200–224 g upon arrival. Wistar rats (male, n = 16; female, n = 16) were bred in-house; they were 11–16 weeks of age upon behavioral testing. The Wistar rats used in this study were derived from Crh-Cre rats [33 (link)] obtained from the laboratory of Robert Messing at the University of Texas at Austin. These rats were bred in our laboratory with commercially supplied wild-type Wistar rats (Envigo, Indianapolis, IN). The Wistar rats were genotyped and randomly assigned to groups (extinction type) within each litter; both Cre⁺ and Cre⁻rats were included in the experiments and their behavior was identical. All rats were individually housed in a temperature- and humidity-controlled vivarium, with a 14:10 hour light/dark cycle and ad libitum access to food and water. Behavioral testing was conducted during the light phase. Rats were handled 1 minute per day for 5 days prior to testing to acclimate them to the experimenter.

Male and female adult Long-Evans Blue Spruce rats, initially weighing between 200 - 240 g (~8 weeks old), were sourced from Envigo in Indianapolis, IN. Each rat was accommodated individually in transparent plastic enclosures within a temperature-regulated vivarium. The environment followed a steady 14:10 h light to dark pattern, with illumination beginning at 7:00 AM. Experiments were exclusively performed during the illuminated period. The rats had unrestricted access to food and water. For at least 5 days before any surgical or behavioral actions commenced, experimenters interacted with the rats, handling them for about 30 s each day. All the experimental methodologies adhered to the guidelines set by the US National Institutes of Health (NIH) for the Care and Use of Laboratory Animals and received approval from the Institutional Animals Care and Use Committee (IACUC) at Texas A&M University.