scramble footshock  (Coulbourn Instruments)

Journal: Frontiers in Neuroscience

Article Title: Conflict Test Battery for Studying the Act of Facing Threats in Pursuit of Rewards

doi: 10.3389/fnins.2021.645769

Figure Lengend Snippet: Diazepam decreases crossing latencies and hesitation events during conflict without affecting no-conflict trials. (A) Rats acquired crossing-mediated conflict 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 the 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 crossing-mediated conflict 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 (top) and hesitation events toward the reward site (bottom) during Conflict trials and similarly low crossing latencies and hesitations events during No-conflict ( left , trials averages of experimental groups; right , trial by trial performance of representative rats). The following day, after injection (test), the diazepam-treated rats decreased crossing latencies (top) and hesitation events (bottom) during conflict trials (no shock) while leaving no-conflict trials intact, as compared to the saline-treated rats ( left , trial averages of experimental groups; right , trial by trial performance of the same representative rats shown in pretest). (C) Rats were separately trained in threat and reward conditioning tasks. Before (pre-test) and after (test) injection, SAL and DZPM groups (SAL, n = 5; DZPM, n = 5) showed similar reactive freezing responses during aversive conditioning and numbers of lever presses per minute during appetitive conditioning (SAL, n = 6; DZPM, n = 7). Error bars indicate Standard Error of Mean (SEM). BL, baseline. ** p < 0.01; *** p < 0.001.

Article Snippet: The floor of the “threat” zone (30 cm long × 25 cm wide) consisted of stainless-steel bars (4.8 mm diameter) delivering a scrambled footshock (Coulbourn Instruments, United States), while the floor of the “safe” zone (20 cm long × 23.5 cm wide × 6 cm tall) was an acrylic-covered elevated step platform.

Techniques: Injection, Saline

Journal: Frontiers in Neuroscience

Article Title: Conflict Test Battery for Studying the Act of Facing Threats in Pursuit of Rewards

doi: 10.3389/fnins.2021.645769

Figure Lengend Snippet: Diazepam decreases step-down latencies and stretched postures during the conflict test without affecting no-conflict conditions. (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 from 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 (not thirsty) stepped down the platform to obtain saccharin solution, followed by learning that stepping down was associated with footshock delivery in the grid. Time to step down with four paws onto the grid (latency in seconds) is presented by a single trial per day. By the end of the training, both groups showed high latencies to step down. (B) Before injection (pre-test), SAL and DZPM groups, in both conflict ( left , black) and no-conflict ( right , green) conditions, showed high latencies to step down (top) and stretched postures (stretches, bottom) toward the reward site. The following day, after injection (test), DZPM-treated rats decreased step-down latencies (top) and the numbers of stretches (bottom) during the conflict condition ( n = 7) without affecting the no-conflict condition ( n = 6), as compared to the SAL-treated rats ( n = 10 and n = 6, respectively). The inset graphs show the percent of rats that successfully stepped down from the platform to approach the reward [latencies (top) and the rats that displayed stretches (bottom)] during both conflict and no-conflict conditions before (pre-test) and after (test) drug manipulation. (C) Rats in their home cages showed similar levels of saccharin intake before (pretest) and after (test) injection of SAL and DZPM (SAL, n = 4; DZPM, n = 5). Error bars indicate SEM. * p < 0.05.

Article Snippet: The floor of the “threat” zone (30 cm long × 25 cm wide) consisted of stainless-steel bars (4.8 mm diameter) delivering a scrambled footshock (Coulbourn Instruments, United States), while the floor of the “safe” zone (20 cm long × 23.5 cm wide × 6 cm tall) was an acrylic-covered elevated step platform.

Techniques: Injection