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Henry DS, Pellegrino RG. A case-control study of phosphodiesterase-5 inhibitor use and Alzheimer's disease and related dementias among male and female patients aged 65 years and older supporting the need for a phase III clinical trial. PLoS One 2023; 18:e0292863. [PMID: 37851623 PMCID: PMC10584171 DOI: 10.1371/journal.pone.0292863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 10/02/2023] [Indexed: 10/20/2023] Open
Abstract
BACKGROUND Phosphodiesterase-5 inhibitors (PDE5i) have been evaluated as a novel treatment for Alzheimer's disease and related dementias (ADRD), but two recent cohort studies have offered opposing conclusions. METHODS We performed an unmatched case-control study using electronic medical records from a large healthcare system to evaluate the association of PDE5i use and ADRD in patients ≥65 years old. RESULTS Odds of PDE5i exposure were 64.2%, 55.7%, and 54.0% lower in patients with ADRD than controls among populations with erectile dysfunction, benign prostatic hyperplasia, and pulmonary hypertension, respectively. We observed odds ratios less than unity among males and females and with exposure to the PDE5i sildenafil (Viagra®) and tadalafil (Cialis®). We also evaluated the odds of exposure to two other common treatments for pulmonary hypertension: endothelin receptor antagonists (ERA) and calcium channel blockers (CCB). The odds of ERA exposure were 63.2% lower, but the odds of CCB exposure were 30.7% higher, in patients with ADRD than controls among the population with pulmonary hypertension. CONCLUSIONS Our results reconcile the opposing conclusions from the previous observational studies and support further research into using PDE5i for prevention and treatment of ADRD.
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Affiliation(s)
- David S. Henry
- Baptist Health Center for Clinical Research, Little Rock, Arkansas, United States of America
| | - Richard G. Pellegrino
- Baptist Health Center for Clinical Research, Little Rock, Arkansas, United States of America
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2
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Tropea MR, Gulisano W, Vacanti V, Arancio O, Puzzo D, Palmeri A. Nitric oxide/cGMP/CREB pathway and amyloid-beta crosstalk: From physiology to Alzheimer's disease. Free Radic Biol Med 2022; 193:657-668. [PMID: 36400326 DOI: 10.1016/j.freeradbiomed.2022.11.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/30/2022] [Accepted: 11/12/2022] [Indexed: 11/17/2022]
Abstract
The nitric oxide (NO)/cGMP pathway has been extensively studied for its pivotal role in synaptic plasticity and memory processes, resulting in an increase of cAMP response element-binding (CREB) phosphorylation, and consequent synthesis of plasticity-related proteins. The NO/cGMP/CREB signaling is downregulated during aging and neurodegenerative disorders and is affected by Amyloid-β peptide (Aβ) and tau protein, whose increase and deposition is considered the key pathogenic event of Alzheimer's disease (AD). On the other hand, in physiological conditions, the crosstalk between the NO/cGMP/PKG/CREB pathway and Aβ ensures long-term potentiation and memory formation. This review summarizes the current knowledge on the interaction between the NO/cGMP/PKG/CREB pathway and Aβ in the healthy and diseased brain, offering a new perspective to shed light on AD pathophysiology. We will focus on the synaptic mechanisms underlying Aβ physiological interplay with cGMP pathway and how this balance is corrupted in AD, as high levels of Aβ interfere with NO production and cGMP molecular signaling leading to cognitive impairment. Finally, we will discuss results from preclinical and clinical studies proposing the increase of cGMP signaling as a therapeutic strategy in the treatment of AD.
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Affiliation(s)
- Maria Rosaria Tropea
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Walter Gulisano
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Valeria Vacanti
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Ottavio Arancio
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, USA; Department of Pathology & Cell Biology and Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy; Oasi Research Institute-IRCCS, Troina (EN), 94018, Italy.
| | - Agostino Palmeri
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
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3
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Nelissen E, Argyrousi EK, Van Goethem NP, Zhao F, Hines CDG, Swaminath G, Gerisch M, Hueser J, Sandner P, Prickaerts J. Soluble Guanylate Cyclase Stimulator Vericiguat Enhances Long-Term Memory in Rats without Altering Cerebral Blood Volume. Biomedicines 2021; 9:1047. [PMID: 34440254 PMCID: PMC8393324 DOI: 10.3390/biomedicines9081047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 01/14/2023] Open
Abstract
Vascular cognitive impairment (VCI) is characterized by impairments in cerebral blood flow (CBF), endothelial function and blood-brain barrier (BBB) integrity. These processes are all physiologically regulated by the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cGMP signaling pathway. Additionally, cGMP signaling plays an important role in long-term potentiation (LTP) underlying memory formation. Therefore, targeting the NO-sGC-cGMP pathway may be a therapeutic strategy for treating VCI. Hence, in this study we investigated whether sGC stimulator vericiguat has potential as a cognitive enhancer. The effects of vericiguat on long-term memory were measured in rats using an object location task. Due to the low brain-penetrance of vericiguat found in this study, it was investigated whether in the absence of BBB limitations, vericiguat enhanced hippocampal plasticity using an ex vivo memory acquisition-like chemical LTP model. Finally, peripheral effects were measured by means of blood pressure and cerebral blood volume. Vericiguat successfully enhanced long-term memory and increased hippocampal plasticity via enhanced translocation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors to the cell membrane, while blood pressure and cerebral blood volume were unaltered. Although the memory enhancing effects in this study are likely due to peripheral effects on the cerebral microvasculature, sGC stimulation may provide a new therapeutic strategy for treating VCI, especially when BBB integrity is reduced.
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Affiliation(s)
- Ellis Nelissen
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands; (E.N.); (E.K.A.); (N.P.V.G.)
| | - Elentina K. Argyrousi
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands; (E.N.); (E.K.A.); (N.P.V.G.)
| | - Nick P. Van Goethem
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands; (E.N.); (E.K.A.); (N.P.V.G.)
| | - Fuqiang Zhao
- Merck & Co., Inc., Kenilworth, NJ 07033, USA; (F.Z.); (C.D.G.H.)
| | | | | | - Michael Gerisch
- Bayer AG, Pharmaceuticals R&D, Pharma Research Center, 42113 Wuppertal, Germany; (M.G.); (J.H.); (P.S.)
| | - Joerg Hueser
- Bayer AG, Pharmaceuticals R&D, Pharma Research Center, 42113 Wuppertal, Germany; (M.G.); (J.H.); (P.S.)
| | - Peter Sandner
- Bayer AG, Pharmaceuticals R&D, Pharma Research Center, 42113 Wuppertal, Germany; (M.G.); (J.H.); (P.S.)
- Hannover Medical School, Institute for Pharmacology, 30625 Hannover, Germany
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands; (E.N.); (E.K.A.); (N.P.V.G.)
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4
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Memory Enhancers for Alzheimer's Dementia: Focus on cGMP. Pharmaceuticals (Basel) 2021; 14:ph14010061. [PMID: 33451088 PMCID: PMC7828493 DOI: 10.3390/ph14010061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 02/06/2023] Open
Abstract
Cyclic guanosine-3',5'-monophosphate, better known as cyclic-GMP or cGMP, is a classical second messenger involved in a variety of intracellular pathways ultimately controlling different physiological functions. The family of guanylyl cyclases that includes soluble and particulate enzymes, each of which comprises several isoforms with different mechanisms of activation, synthesizes cGMP. cGMP signaling is mainly executed by the activation of protein kinase G and cyclic nucleotide gated channels, whereas it is terminated by its hydrolysis to GMP operated by both specific and dual-substrate phosphodiesterases. In the central nervous system, cGMP has attracted the attention of neuroscientists especially for its key role in the synaptic plasticity phenomenon of long-term potentiation that is instrumental to memory formation and consolidation, thus setting off a "gold rush" for new drugs that could be effective for the treatment of cognitive deficits. In this article, we summarize the state of the art on the neurochemistry of the cGMP system and then review the pre-clinical and clinical evidence on the use of cGMP enhancers in Alzheimer's disease (AD) therapy. Although preclinical data demonstrates the beneficial effects of cGMP on cognitive deficits in AD animal models, the results of the clinical studies carried out to date are not conclusive. More trials with a dose-finding design on selected AD patient's cohorts, possibly investigating also combination therapies, are still needed to evaluate the clinical potential of cGMP enhancers.
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Ribaudo G, Ongaro A, Zagotto G, Memo M, Gianoncelli A. Therapeutic Potential of Phosphodiesterase Inhibitors against Neurodegeneration: The Perspective of the Medicinal Chemist. ACS Chem Neurosci 2020; 11:1726-1739. [PMID: 32401481 PMCID: PMC8007108 DOI: 10.1021/acschemneuro.0c00244] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
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Increasing human
life expectancy prompts the development of novel
remedies for cognitive decline: 44 million people worldwide are affected
by dementia, and this number is predicted to triple by 2050. Acetylcholinesterase
and N-methyl-d-aspartate receptors represent
the targets of currently available drugs for Alzheimer’s disease,
which are characterized by limited efficacy. Thus, the search for
therapeutic agents with alternative or combined mechanisms of action
is wide open. Since variations in 3′,5′-cyclic adenosine
monophosphate, 3′,5′-cyclic guanosine monophosphate,
and/or nitric oxide levels interfere with downstream pathways involved
in memory processes, evidence supporting the potential of phosphodiesterase
(PDE) inhibitors in contrasting neurodegeneration should be
critically considered. For the preparation of this Review, more than
140 scientific papers were retrieved by searching PubMed and Scopus
databases. A systematic approach was adopted when overviewing the
different PDE isoforms, taking into account details on brain localization,
downstream molecular mechanisms, and inhibitors currently under study,
according to available in vitro and in vivo data. In the context of drug repurposing, a section focusing on
PDE5 was introduced. Original computational studies were performed
to rationalize the emerging evidence that suggests the role of PDE5
inhibitors as multi-target agents against neurodegeneration.
Moreover, since such compounds must cross the blood–brain barrier
and reach inhibitory concentrations in the central nervous system
to exert their therapeutic activity, physicochemical parameters
were analyzed and discussed. Taken together, literature and computational
data suggest that some PDE5 inhibitors, such as tadalafil, represent
promising candidates.
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Affiliation(s)
- Giovanni Ribaudo
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Alberto Ongaro
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Giuseppe Zagotto
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via Marzolo 5, 35131 Padova, Italy
| | - Maurizio Memo
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Alessandra Gianoncelli
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
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6
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Caudano F, Montalto G, Passalacqua M, Pronzato MA, Fedele E, Ricciarelli R. cGMP favors the interaction between APP and BACE1 by inhibiting Rab5 GTPase activity. Sci Rep 2020; 10:1358. [PMID: 31992816 PMCID: PMC6987147 DOI: 10.1038/s41598-020-58476-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 01/13/2020] [Indexed: 11/12/2022] Open
Abstract
We previously demonstrated that cyclic guanosine monophosphate (cGMP) stimulates amyloid precursor protein (APP) and beta-secretase (BACE1) approximation in neuronal endo-lysosomal compartments, thus boosting the production of amyloid-β (Aβ) peptides and enhancing synaptic plasticity and memory. Here, we further investigated the mechanism by which cGMP regulates the subcellular localization of APP and BACE1, finding that the cyclic nucleotide inhibits the activity of Rab5, a small GTPase associated with the plasma membrane and early endosomes. Accordingly, we also found that expression of a dominant-negative Rab5 mutant increases both APP-BACE1 approximation and Aβ extracellular levels, therefore mimicking the effects induced by cGMP. These results reveal a functional correlation between the cGMP/Aβ pathway and the activity of Rab5 that may contribute to the understanding of Alzheimer’s disease pathophysiology.
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Affiliation(s)
- Francesca Caudano
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Giulia Montalto
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Mario Passalacqua
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Maria A Pronzato
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Ernesto Fedele
- Department of Pharmacy and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Roberta Ricciarelli
- Department of Experimental Medicine, University of Genoa, Genoa, Italy. .,IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
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7
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Blokland A, Heckman P, Vanmierlo T, Schreiber R, Paes D, Prickaerts J. Phosphodiesterase Type 4 Inhibition in CNS Diseases. Trends Pharmacol Sci 2019; 40:971-985. [DOI: 10.1016/j.tips.2019.10.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/15/2019] [Accepted: 10/17/2019] [Indexed: 12/17/2022]
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8
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Baillie GS, Tejeda GS, Kelly MP. Therapeutic targeting of 3',5'-cyclic nucleotide phosphodiesterases: inhibition and beyond. Nat Rev Drug Discov 2019; 18:770-796. [PMID: 31388135 PMCID: PMC6773486 DOI: 10.1038/s41573-019-0033-4] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2019] [Indexed: 01/24/2023]
Abstract
Phosphodiesterases (PDEs), enzymes that degrade 3',5'-cyclic nucleotides, are being pursued as therapeutic targets for several diseases, including those affecting the nervous system, the cardiovascular system, fertility, immunity, cancer and metabolism. Clinical development programmes have focused exclusively on catalytic inhibition, which continues to be a strong focus of ongoing drug discovery efforts. However, emerging evidence supports novel strategies to therapeutically target PDE function, including enhancing catalytic activity, normalizing altered compartmentalization and modulating post-translational modifications, as well as the potential use of PDEs as disease biomarkers. Importantly, a more refined appreciation of the intramolecular mechanisms regulating PDE function and trafficking is emerging, making these pioneering drug discovery efforts tractable.
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Affiliation(s)
- George S Baillie
- Institute of Cardiovascular and Medical Science, University of Glasgow, Glasgow, UK
| | - Gonzalo S Tejeda
- Institute of Cardiovascular and Medical Science, University of Glasgow, Glasgow, UK
| | - Michy P Kelly
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA.
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9
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Liu L, Xu H, Ding S, Wang D, Song G, Huang X. Phosphodiesterase 5 inhibitors as novel agents for the treatment of Alzheimer's disease. Brain Res Bull 2019; 153:223-231. [PMID: 31493542 DOI: 10.1016/j.brainresbull.2019.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/18/2019] [Accepted: 09/01/2019] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD), characterized by a progressive impairment of memory and cognition, is a major health problem in both developing and developed countries. Currently, no drugs can reverse the progression of AD. Phosphodiesterase 5 (PDE5) is a critical component of the cyclic guanosine monophosphate/protein kinase G (cGMP/PKG) signaling pathway in neurons, the inhibition of which has produced neuroprotective effects, and PDE5 inhibitors have recently been thought to be potential therapeutic agents for AD. In this paper, we summarized the outstanding progress that has been made in PDE5 inhibitors as anti-AD agents with encouraging results in animal studies, clinical trials and the investigations on the underlying mechanisms. The novel PDE5 inhibitors reported recently in the treatment of AD were also reviewed and discussed.
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Affiliation(s)
- Li Liu
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Huang Xu
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Shumin Ding
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Dongyan Wang
- Department of Medicine, Yangzhou Polytechnic College, Yangzhou, Jiangsu 225009, China
| | - Guoqiang Song
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China.
| | - Xianfeng Huang
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China.
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10
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Acute administration of roflumilast enhances immediate recall of verbal word memory in healthy young adults. Neuropharmacology 2018; 131:31-38. [DOI: 10.1016/j.neuropharm.2017.12.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 12/07/2017] [Accepted: 12/09/2017] [Indexed: 12/31/2022]
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11
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Heckman PRA, Blokland A, Bollen EPP, Prickaerts J. Phosphodiesterase inhibition and modulation of corticostriatal and hippocampal circuits: Clinical overview and translational considerations. Neurosci Biobehav Rev 2018; 87:233-254. [PMID: 29454746 DOI: 10.1016/j.neubiorev.2018.02.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 02/07/2018] [Accepted: 02/09/2018] [Indexed: 12/20/2022]
Abstract
The corticostriatal and hippocampal circuits contribute to the neurobiological underpinnings of several neuropsychiatric disorders, including Alzheimer's disease, Parkinson's disease and schizophrenia. Based on biological function, these circuits can be clustered into motor circuits, associative/cognitive circuits and limbic circuits. Together, dysfunctions in these circuits produce the wide range of symptoms observed in related neuropsychiatric disorders. Intracellular signaling in these circuits is largely mediated through the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway with an additional role for the cyclic guanosine monophosphate (cGMP)/ protein kinase G (PKG) pathway, both of which can be regulated by phosphodiesterase inhibitors (PDE inhibitors). Through their effects on cAMP response element-binding protein (CREB) and Dopamine- and cAMP-Regulated PhosphoProtein MR 32 kDa (DARPP-32), cyclic nucleotide pathways are involved in synaptic transmission, neuron excitability, neuroplasticity and neuroprotection. In this clinical review, we provide an overview of the current clinical status, discuss the general mechanism of action of PDE inhibitors in relation to the corticostriatal and hippocampal circuits and consider several translational challenges.
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Affiliation(s)
- P R A Heckman
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands; Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, The Netherlands.
| | - A Blokland
- Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - E P P Bollen
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - J Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
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12
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Prickaerts J, Heckman PRA, Blokland A. Investigational phosphodiesterase inhibitors in phase I and phase II clinical trials for Alzheimer's disease. Expert Opin Investig Drugs 2017; 26:1033-1048. [PMID: 28772081 DOI: 10.1080/13543784.2017.1364360] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Phosphodiesterase (PDE) inhibitors improve signaling pathways in brain circuits by increasing intracellular cyclic adenosine monophosphate (cAMP) and/or cyclic guanosine monophosphate (cGMP). In the last decade, the first clinical studies investigating selective PDE inhibitors in Alzheimer's disease (AD) have been initiated, based on their positive effects on cognitive processes and neuroprotection in numerous animal studies. Areas covered: This article reviews the clinical studies investigating the pro-cognitive/neuroprotective effects of PDE inhibitors in patients with AD, as well as in age-associated memory impaired elderly and patients with mild cognitive impairment (MCI), the prodromal stage of AD. PDE inhibitors will also be discussed with respect to adverse effects including safety and tolerability. Expert opinion: The limited available data of clinical studies with PDE inhibitors tested in different populations of AD patients do not allow the drawing of any concrete conclusion yet. Currently, studies with a PDE3 (cilostazol) or PDE9 inhibitor (BI 409,306) are still ongoing in patients with MCI or AD, respectively. Studies with PDE4 inhibitors (HT-0712, roflumilast and BPN14770) in healthy elderly and elderly with age-associated memory impairments indicate that the optimum dose and/or inhibiting the most relevant PDE isoform hold great promise when tested in the appropriate population of patients with MCI or AD eventually.
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Affiliation(s)
- Jos Prickaerts
- a Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience , Maastricht University , Maastricht , The Netherlands
| | - Pim R A Heckman
- a Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience , Maastricht University , Maastricht , The Netherlands.,b Department of Neuropsychology and Psychopharmacology , Maastricht University , Maastricht , The Netherlands
| | - Arjan Blokland
- b Department of Neuropsychology and Psychopharmacology , Maastricht University , Maastricht , The Netherlands
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13
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Teich AF, Sakurai M, Patel M, Holman C, Saeed F, Fiorito J, Arancio O. PDE5 Exists in Human Neurons and is a Viable Therapeutic Target for Neurologic Disease. J Alzheimers Dis 2017; 52:295-302. [PMID: 26967220 PMCID: PMC4927884 DOI: 10.3233/jad-151104] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Phosphodiesterase 5 (PDE5) is a critical component of the cGMP-PKG axis of cellular signaling in neurons, and inhibition of PDE5 has been shown to be therapeutic in a wide range of neurologic conditions in animal models. However, enthusiasm for PDE5 inhibitors in humans is limited by data suggesting that PDE5 may not exist in human neurons. Here, we first show that past attempts to quantify PDE5 mRNA were flawed due to the use of incorrect primers, and that when correct primers are used, PDE5 mRNA is detectable in human brain tissue. We then show that PDE5 protein exists in human brain by western blot and ELISA. Most importantly, we performed immunohistochemistry and demonstrate that PDE5 is present in human neurons. We hope that this work will trigger a renewed interest in the development of PDE5 inhibitors for neurologic disease.
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Affiliation(s)
- Andrew F Teich
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Mikako Sakurai
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Mitesh Patel
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Cameron Holman
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Faisal Saeed
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Jole Fiorito
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
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14
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Heckman PRA, Blokland A, Prickaerts J. From Age-Related Cognitive Decline to Alzheimer's Disease: A Translational Overview of the Potential Role for Phosphodiesterases. ADVANCES IN NEUROBIOLOGY 2017; 17:135-168. [PMID: 28956332 DOI: 10.1007/978-3-319-58811-7_6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Phosphodiesterase inhibitors (PDE-Is) are pharmacological compounds enhancing cAMP and/or cGMP signaling. Both these substrates affect neural communication by influencing presynaptic neurotransmitter release and postsynaptic intracellular pathways after neurotransmitter binding to its receptor. Both cAMP and cGMP play an important role in a variety of cellular functions including neuroplasticity and neuroprotection. This chapter provides a translational overview of the effects of different classes of PDE-Is on cognition enhancement in age-related cognitive decline and Alzheimer's disease (AD). The most effective PDE-Is in preclinical models of aging and AD appear to be PDE2-Is, PDE4-Is and PDE5-Is. Clinical studies are relatively sparse and so far PDE1-Is and PDE4-Is showed some promising results. In the future, the demonstration of clinical proof of concept and the generation of isoform selective PDE-Is are the hurdles to overcome in developing safe and efficacious novel PDE-Is for the treatment of age-related cognitive decline and cognitive dysfunction in AD.
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Affiliation(s)
- Pim R A Heckman
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
- Department of Neuropsychology and Psychopharmacology, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands.
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Pharmacological Rescue of Long-Term Potentiation in Alzheimer Diseased Synapses. J Neurosci 2016; 37:1197-1212. [PMID: 27986924 DOI: 10.1523/jneurosci.2774-16.2016] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/05/2016] [Accepted: 12/09/2016] [Indexed: 01/05/2023] Open
Abstract
Long-term potentiation (LTP) is an activity-dependent and persistent increase in synaptic transmission. Currently available techniques to measure LTP are time-intensive and require highly specialized expertise and equipment, and thus are not well suited for screening of multiple candidate treatments, even in animal models. To expand and facilitate the analysis of LTP, here we use a flow cytometry-based method to track chemically induced LTP by detecting surface AMPA receptors in isolated synaptosomes: fluorescence analysis of single-synapse long-term potentiation (FASS-LTP). First, we demonstrate that FASS-LTP is simple, sensitive, and models electrically induced LTP recorded in intact circuitries. Second, we conducted FASS-LTP analysis in two well-characterized Alzheimer's disease (AD) mouse models (3xTg and Tg2576) and, importantly, in cryopreserved human AD brain samples. By profiling hundreds of synaptosomes, our data provide the first direct evidence to support the idea that synapses from AD brain are intrinsically defective in LTP. Third, we used FASS-LTP for drug evaluation in human synaptosomes. Testing a panel of modulators of cAMP and cGMP signaling pathways, FASS-LTP identified vardenafil and Bay-73-6691 (phosphodiesterase-5 and -9 inhibitors, respectively) as potent enhancers of LTP in synaptosomes from AD cases. These results indicate that our approach could provide the basis for protocols to study LTP in both healthy and diseased human brains, a previously unattainable goal. SIGNIFICANCE STATEMENT Learning and memory depend on the ability of synapses to strengthen in response to activity. Long-term potentiation (LTP) is a rapid and persistent increase in synaptic transmission that is thought to be affected in Alzheimer's disease (AD). However, direct evidence of LTP deficits in human AD brain has been elusive, primarily due to methodological limitations. Here, we analyze LTP in isolated synapses from AD brain using a novel approach that allows testing LTP in cryopreserved brain. Our analysis of hundreds of synapses supports the idea that AD-diseased synapses are intrinsically defective in LTP. Further, we identified pharmacological agents that rescue LTP in AD, thus opening up a new avenue for drug screening and evaluation of strategies for alleviating memory impairments.
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Franco R. Enhancing cognition before clinical symptoms of dementia. Front Syst Neurosci 2015; 8:240. [PMID: 25565993 PMCID: PMC4267185 DOI: 10.3389/fnsys.2014.00240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 12/01/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Rafael Franco
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona Barcelona, Spain ; CIBERNED: Centro de Investigación en Red sobre Enfermedades Neurodegenerativas, Instituto de Investigación Carlos III Madrid, Spain
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Rivastigmine but not vardenafil reverses cannabis-induced impairment of verbal memory in healthy humans. Psychopharmacology (Berl) 2015; 232:343-53. [PMID: 24998257 DOI: 10.1007/s00213-014-3667-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/16/2014] [Indexed: 12/18/2022]
Abstract
RATIONALE One of the most often reported cognitive deficits of acute cannabis administration is an impaired recall of previously learned information. OBJECTIVE The aim of the present study was to determine whether cannabis-induced memory impairment in humans is mediated via glutamatergic or cholinergic pathways. METHODS Fifteen occasional cannabis users participated in a double-blind, placebo-controlled, six-way cross-over study. On separate test days, subjects received combinations of pretreatment (placebo, vardenafil 20 mg or rivastigmine 3 mg) and treatment (placebo or 1,376 mg cannabis/kg body weight). Cognitive tests were administered immediately after inhalation of treatment was finished and included measures of memory (visual verbal learning task, prospective memory test, Sternberg memory test), perceptual-motor control (critical tracking task), attention (divided attention task) and motor impulsivity (stop signal task). RESULTS The results of this study demonstrate that subjects under the influence of cannabis were impaired in all memory tasks, in critical tracking, divided attention and the stop signal task. Pretreatment with rivastigmine attenuated the effect of cannabis on delayed recall and showed a trend towards significance on immediate recall. When cannabis was given in combination with vardenafil, there were no significant interaction effects in any of the tasks. CONCLUSIONS The present data therefore suggest that acetylcholine plays an important role in cannabis-induced memory impairment, whereas similar results for glutamate have not been demonstrated in this study.
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Abstract
Declarative Memory consists of memory for events (episodic memory) and facts (semantic memory). Methods to test declarative memory are key in investigating effects of potential cognition-enhancing substances--medicinal drugs or nutrients. A number of cognitive performance tests assessing declarative episodic memory tapping verbal learning, logical memory, pattern recognition memory, and paired associates learning are described. These tests have been used as outcome variables in 34 studies in humans that have been described in the literature in the past 10 years. Also, the use of episodic tests in animal research is discussed also in relation to the drug effects in these tasks. The results show that nutritional supplementation of polyunsaturated fatty acids has been investigated most abundantly and, in a number of cases, but not all, show indications of positive effects on declarative memory, more so in elderly than in young subjects. Studies investigating effects of registered anti-Alzheimer drugs, cholinesterase inhibitors in mild cognitive impairment, show positive and negative effects on declarative memory. Studies mainly carried out in healthy volunteers investigating the effects of acute dopamine stimulation indicate enhanced memory consolidation as manifested specifically by better delayed recall, especially at time points long after learning and more so when drug is administered after learning and if word lists are longer. The animal studies reveal a different picture with respect to the effects of different drugs on memory performance. This suggests that at least for episodic memory tasks, the translational value is rather poor. For the human studies, detailed parameters of the compositions of word lists for declarative memory tests are discussed and it is concluded that tailored adaptations of tests to fit the hypothesis under study, rather than "off-the-shelf" use of existing tests, are recommended.
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Affiliation(s)
- Wim J Riedel
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Universiteitssingel 40, 6229ER, Maastricht, The Netherlands,
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Heckman PRA, Blokland A, Ramaekers J, Prickaerts J. PDE and cognitive processing: beyond the memory domain. Neurobiol Learn Mem 2014; 119:108-22. [PMID: 25464010 DOI: 10.1016/j.nlm.2014.10.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 01/01/2023]
Abstract
Phosphodiesterase inhibitors (PDE-Is) enhance cAMP and/or cGMP signaling via reducing the degradation of these cyclic nucleotides. Both cAMP and cGMP signaling are essential for a variety of cellular functions and exert their effects both pre- and post-synaptically. Either of these second messengers relays and amplifies incoming signals at receptors on the cell surface making them important elements in signal transduction cascades and essential in cellular signaling in a variety of cell functions including neurotransmitter release and neuroprotection. Consequently, these processes can be influenced by PDE-Is as they increase cAMP and/or cGMP concentrations. PDE-Is have been considered as possible therapeutic agents to treat impaired memory function linked to several brain disorders, including depression, schizophrenia and Alzheimer's disease (AD). This review will, however, focus on the possible role of phosphodiesterases (PDEs) in cognitive decline beyond the memory domain. Here we will discuss the involvement of PDEs on three related domains: attention, information filtering (sensory- and sensorimotor gating) and response inhibition (drug-induced hyperlocomotion). Currently, these are emerging cognitive domains in the field of PDE research. Here we discuss experimental studies and the potential beneficial effects of PDE-I drugs on these cognitive domains, as effects of PDE-Is on these domains could potentially influence effects on memory performance. Overall, PDE4 seems to be the most promising target for all domains discussed in this review.
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Affiliation(s)
- P R A Heckman
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands; Department of Neuropsychology and Psychopharmacology, Maastricht University, 6200 MD Maastricht, The Netherlands
| | - A Blokland
- Department of Neuropsychology and Psychopharmacology, Maastricht University, 6200 MD Maastricht, The Netherlands
| | - J Ramaekers
- Department of Neuropsychology and Psychopharmacology, Maastricht University, 6200 MD Maastricht, The Netherlands
| | - J Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands.
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Akkerman S, Prickaerts J, Bruder AK, Wolfs KHM, De Vry J, Vanmierlo T, Blokland A. PDE5 inhibition improves object memory in standard housed rats but not in rats housed in an enriched environment: implications for memory models? PLoS One 2014; 9:e111692. [PMID: 25372140 PMCID: PMC4221101 DOI: 10.1371/journal.pone.0111692] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/29/2014] [Indexed: 12/20/2022] Open
Abstract
Drug effects are usually evaluated in animals housed under maximally standardized conditions. However, it is assumed that an enriched environment (EE) more closely resembles human conditions as compared to maximally standardized laboratory conditions. In the present study, we examined the acute cognition enhancing effects of vardenafil, a PDE5 inhibitor, which stimulates protein kinase G/CREB signaling in cells, in three different groups of male Wistar rats tested in an object recognition task (ORT). Rats were either housed solitarily (SOL) or socially (SOC) under standard conditions, or socially in an EE. Although EE animals remembered object information longer in the vehicle condition, vardenafil only improved object memory in SOL and SOC animals. While EE animals had a heavier dorsal hippocampus, we found no differences between experimental groups in total cell numbers in the dentate gyrus, CA2-3 or CA1. Neither were there any differences in markers for pre- and postsynaptic density. No changes in PDE5 mRNA- and protein expression levels were observed. Basal pCREB levels were increased in EE rats only, whereas β-catenin was not affected, suggesting specific activation of the MAP kinase signaling pathway and not the AKT pathway. A possible explanation for the inefficacy of vardenafil could be that CREB signaling is already optimally stimulated in the hippocampus of EE rats. Since previous data has shown that acute PDE5 inhibition does not improve memory performance in humans, the use of EE animals could be considered as a more valid model for testing cognition enhancing drugs.
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Affiliation(s)
- Sven Akkerman
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - Ann K. Bruder
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Kevin H. M. Wolfs
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - Jochen De Vry
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - Tim Vanmierlo
- Department of Immunology and Biochemistry, Biomedical research institute, Hasselt University, Hasselt, Belgium
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
- * E-mail:
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Blokland A, van Goethem N, Heckman P, Schreiber R, Prickaerts J. Translational issues with the development of cognition enhancing drugs. Front Neurol 2014; 5:190. [PMID: 25309509 PMCID: PMC4174861 DOI: 10.3389/fneur.2014.00190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 09/11/2014] [Indexed: 12/16/2022] Open
Affiliation(s)
- Arjan Blokland
- Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University , Maastricht , Netherlands
| | - Nick van Goethem
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University , Maastricht , Netherlands
| | - Pim Heckman
- Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University , Maastricht , Netherlands ; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University , Maastricht , Netherlands
| | | | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University , Maastricht , Netherlands
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PDE2 and PDE10, but not PDE5, inhibition affect basic auditory information processing in rats. Behav Brain Res 2013; 250:251-6. [DOI: 10.1016/j.bbr.2013.05.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 01/08/2023]
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