The novel selective PDE9 inhibitor BAY 73-6691 improves learning and memory in rodents

F.J. van der Staay*, K. Rutten, L. Barfacker, J. Devry, C. Erb, H. Heckroth, D. Karthaus, A. Tersteegen, M. van Kampen, A. Blokland, J.H.H.J. Prickaerts, K.G. Reymann, U.H. Schroder, M. Hendrix

*Corresponding author for this work

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The present study investigated the putative pro-cognitive effects of the novel selective PDE9 inhibitor BAY 73-6691. The effects on basal synaptic transmission and long-term potentiation (LTP) were investigated in rat hippocampal slices. Pro-cognitive effects were assessed in a series of learning and memory tasks using rodents as subjects. BAY 73-6691 had no effect on basal synaptic transmission in hippocampal slices prepared from young adult (7- to 8-week-old) Wistar rats. A dose of 10 mu M, but not 30 mu M BAY 73-6691 enhanced early LTP after weak tetanic stimulation. The dose effective in young adult Wistar rats did not affect LTP in hippocampal slices prepared from young (7- to 8-week-old) Fischer 344 X Brown Norway (FBNF1) rats, probably reflecting strain differences. However, it increased basal synaptic transmission and enhanced early LTP after weak tetanic stimulation in hippocampal slices prepared from very old (31 - to 35-month-old) FBNF1 rats. BAY 73-6691 enhanced acquisition, consolidation, and retention of long-term memory (LTM) in a social recognition task and tended to enhance LTM in an object recognition task. Bay 73-6691 attenuated the scoplamine-induced retention deficit in a passive avoidance task, and the MK-801-induced short-term memory deficits in a T-maze alternation task. The mechanism of action, possibly through modulation of the NO/cGMP-PKG/CREB pathway, is discussed. Our findings support the notion that PDE9 inhibition may be a novel target for treating memory deficits that are associated with aging and neurodegenerative disorders such as Alzheimer's disease.
Original languageEnglish
Pages (from-to)908-918
Issue number5
Publication statusPublished - 1 Jan 2008

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