Journal: bioRxiv

Article Title: Conflict-mediated tasks for studying the act of facing threats in pursuit of rewards

doi: 10.1101/2020.12.27.424515

Figure Lengend Snippet: A , Rats acquired conflict-mediated crossing in 30 days (n=14). First, hungry rats, confined to the safe zone (green), learned to associate pressing a lever with food availability cued by a light (reward conditioning), followed by training to cross to the opposite safe zone of the straight alley to obtain food cued by light (no-conflict crossings). Then, rats, confined to the threat zone (grid, red) of the alley, learned to associate occurrence of white noise with a mild footshock (threat conditioning), followed by training to cross with both learned contingencies (light/food and noise/shock) presented simultaneously (conflict crossings). Finally, rats were trained to discriminate crossing trials guided by no-conflict (light/food alone) or conflict (light/food and noise/shock) cues. Data from lever pressing (per minute) and time to cross to the opposite safe zone of the alley (latency in seconds) are presented in blocks of three trials per day, whereas percent time spent freezing (with or without shock) is presented for each trial. By the end of conflict-mediated crossing training, rats showed high crossing latencies during conflict trials (black) compared to no-conflict trials (green). B , Before injection (pre-Test), saline solution and diazepam groups (SAL, n = 7; DZPM, n = 7) showed similarly high crossing latencies during conflict trials and similarly low latencies during no-conflict ( Left , trials averages; Right trial by trial performance of representative rats). The following day, after injection (Test), diazepam-treated rats decreased crossing latencies during conflict trials (no shock), while leaving no-conflict trials intact, as compared to saline-treated rats ( Left , trial averages; Right , trial by trial performance of the same representative rats shown in pre-test). Error bars indicated SEM. BL, baseline. ** p < 0.01.

Article Snippet: The floor of the “threat” zone was made of stainless-steel bars (4.8 mm diameter) which delivered a scramble footshock (Coulbourn Instruments, USA), while the floor of “safe” zones was made of acrylic.

Techniques: Injection

Journal: bioRxiv

Article Title: Conflict-mediated tasks for studying the act of facing threats in pursuit of rewards

doi: 10.1101/2020.12.27.424515

Figure Lengend Snippet: A , Rats acquired step-down avoidance either mediated by conflict or no-conflict. Left , In the conflict condition (black), rats (n = 17) innately motivated to drink (thirsty) step-down the platform (safe zone, green) to obtain sweetened water (saccharin; reward presentation) from the bottle at the end of the grid, followed by learning that the act of stepping down was associated with the occurrence of a mild footshock in the grid context (threat zone, red). Right , In the no-conflict condition (green), rats (n = 12) with free access to water (sated) stepped down the platform to obtain saccharin solution, followed by learning that stepping down was associated with footshock delivery in the grid. Time to stepdown with four paws onto the grid (latency in seconds) is presented by a single trial per day. By the end of training, both groups showed high latencies to step-down. B , Before injection (pre-Test), saline solution (SAL) and diazepam (DZPM) groups, in both conflict ( Left , black) and no-conflict ( Right , green) conditions, showed high latencies to step-down. The following day, after injection (Test), DZPM-treated rats decreased step-down latencies during the conflict condition ( n = 7) without affecting the no-conflict condition ( n = 6), as compared to SAL-treated rats ( n = 10 and n = 6, respectively). Error bars indicated SEM. * p < 0.05.

Article Snippet: The floor of the “threat” zone was made of stainless-steel bars (4.8 mm diameter) which delivered a scramble footshock (Coulbourn Instruments, USA), while the floor of “safe” zones was made of acrylic.

Techniques: Injection