Chronic inhibition of GABA synthesis in the infralimbic cortex facilitates conditioned safety memory and reduces contextual fear

摘要

Timeline of the study: upon 2 days of handling and the first blood sample (Day −3), male Sprague Dawley rats underwent stereotactic cannulation and mini-pump implantation ( -/ -AG Infusions, Day 0). Following 6–7 days of recovery, a second blood sample (Day 7) was drawn before submitting rats to the first startle habituation session (Day 7). 24 hours later, rats underwent a second startle habituation session (Day 8), as well as the prepulse inhibition test (PPI). Rats were then submitted to our safety conditioning procedure: First, the Pre-Test was conducted (Day 9), followed by two safety conditioning sessions (Day 10 and 11). On the last day we tested for conditioned safety memory in the expression session (Post-Test, Day 12) followed by a final blood sample. Infusion cannula placements in the infralimbic cortex (IL) and photomicrograph of a representative cannula tract ( ). Open symbols in represent individuals of the -AG group, whereas filled symbols represent -AG-treated rats; the numbers in indicate the distance of the histology plate anterior to bregma.