Time-dependent involvement of cAMP and cGMP in consolidation of object memory: studies using selective phosphodiesterase type 2, 4 and 5 inhibitors.
The present study investigated the time-dependent memory enhancing properties of three selective phosphodiesterase inhibitors (PDE-I) vardenafil (PDE5-I), rolipram (PDE4-I) and BAY 60-7550 (PDE2-I) in the object recognition task. In particular, the time-dependent involvement of cAMP and cGMP in memory consolidation was assessed by altering the time points of drug administration. Vardenafil (1 mg/kg, p.o.), rolipram (0.03 mg/kg, i.p.), and BAY 60-7550 (3 mg/kg, p.o.) were tested in rats with a 24 h delay between the learning and the test trial. The PDE-Is were administered at different time points, i.e. directly after, 1 h, 3 h and 6 h after the first trial. Using a 24 h interval, vardenafil only showed an effect on object memory when injected directly after trial 1, rolipram only showed an improvement when injected 3 h after trial 1 and BAY 60-7550 improved memory when injected either directly after or 3 h after trial 1. No treatment effects were found when the compounds were administered 1 h or 6 h after the first trial. Our results extend our previous data that different types of PDE-Is affect different stages of memory consolidation. Moreover, the present study provides further support that selective PDE-Is can influence memory consolidation in a time-dependent manner, assumingly by elevating central cAMP and cGMP levels.
Rutten
Kris
K
Department of Psychiatry and Neuropsychology, Brain and Behavior Institute, EURON, Maastricht University, 6200 MD Maastricht, The Netherlands. k.rutten@np.unimaas.nl
Prickaerts
Jos
J
Hendrix
Martin
M
van der Staay
F Josef
FJ
Sik
Ayhan
A
Blokland
Arjan
A
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000818:Animals; D000242:Cyclic AMP / Q000502:physiology*; D006152:Cyclic GMP / Q000502:physiology*; D054678:Cyclic Nucleotide Phosphodiesterases, Type 2; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010727:Phosphoric Diester Hydrolases / Q000187:drug effects*; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D020889:Rolipram / Q000494:pharmacology; D013450:Sulfones / Q000494:pharmacology; D013997:Time Factors; D014227:Triazines / Q000494:pharmacology; D000069058:Vardenafil Dihydrochloride
D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054678:Cyclic Nucleotide Phosphodiesterases, Type 2; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C517278:Pde2a protein, rat; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517384:Pde5a protein, rat; D006152:Cyclic GMP; D020889:Rolipram