Zaprinast consolidates long-term memory when administered to neonate chicks trained using a weakly reinforced single trial passive avoidance task.
A weakly reinforced variant of the single trial passive avoidance task developed for the day-old chick typically fails to consolidate long-term memory. However, administration of zaprinast, a phosphodiesterase (PDE) type 5 inhibitor, (ic; 10 microl/side) immediately post-training resulted in a dose-dependent increase in retention at test 180 min post-training. Further, 100 microM zaprinast resulted in high levels of retention at test 180 min post-training when administered from 10 min before training to 10 min after training. Finally, 100 microM zaprinast, when administered immediately post-training, resulted in the consolidation of long-term memory at a number of times of test extending as late as 24 h post-training. Inhibition of PDE type 5 is known to increase cellular cGMP levels. Previous investigations using a strongly reinforced variant of this task have suggested a role for cGMP in memory retrieval, we now postulate that cGMP is also necessary for memory formation in chicks trained using passive avoidance.
Campbell
Emma
E
School of Psychology, Psychiatry and Psychological Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Wellington Rd., Clayton, Vic. 3800, Australia.
Edwards
Thomas
T
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D018697:Nootropic Agents / Q000008:administration & dosage*; D011688:Purinones / Q000008:administration & dosage*; D012054:Reinforcement, Psychology; D012153:Retention, Psychology / Q000187:drug effects*
D018697:Nootropic Agents; D011688:Purinones; D015106:3',5'-Cyclic-GMP Phosphodiesterases; C011145:zaprinast