RQ DCS Enhanced Extinction
Davenport RQ agenda: DCS enhance CTA extinction learning?
-Subjects: 32 male Sprague-Dawley rats weighing 250-300g
-4 groups (n = 8 in each):
- sac/veh/veh- injection control, no aversion, baseline preference for saccharin
- sac/veh/DCS- ensure chronic DCS does not cause an aversion
- sac/LiCl/veh- baseline CTA and extinction
- sac/LiCl/DCS- enhance extinction learning?
-All rats water-restricted for 8 days (after 3+ days of habituation to colony room):
- Day 1 = water off
- Days 2 and 3 = 3 h H2O access
- Days 4 and 5 = 1 h H2O access
- Days 6 and 7 = 30 min H2O access
- Days 8 and 9 = 10 min H2O access
-Rats weighed on last day of water restriction to determine LiCl dose.
-Conditioning day (10): All rats will receive 10-min access to a bottle of 0.125% saccharin solution in home cage. At 30 min after the start of saccharin access, rats will be injected with either LiCl (38mg/12ml/kg, i.p.) or saline vehicle. Two hours later, rats will receive 2 h H2O access.
-Extinction days (11+): All rats will receive DCS (15mg/kg, i.p.) or saline vehicle 60 min before 2-hour 2-bottle access to both water and saccharin. Bottles will be refilled with fresh water or saccharin daily and weighed before and after access each day to determine consumption. The water and saccharin bottles will alternate sides in the cage each day to prevent and detect place preferences.