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Mill NR, Ogoe RH, Valibeigi N, Chen D, Kimbal CL, Yoon SJ, Ganju S, Perdomo JA, Sardana A, McHail DG, Gonzalez DA, Dumas TC. Positive modulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors differentially alters spatial learning and memory in juvenile rats younger and older than three weeks. Behav Pharmacol 2024; 35:79-91. [PMID: 38451022 PMCID: PMC10921984 DOI: 10.1097/fbp.0000000000000764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Remarkable performance improvements occur at the end of the third postnatal week in rodents tested in various tasks that require navigation according to spatial context. While alterations in hippocampal function at least partially subserve this cognitive advancement, physiological explanations remain incomplete. Previously, we discovered that developmental modifications to hippocampal glutamatergic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in juvenile rats was related to more mature spontaneous alternation behavior in a symmetrical Y-maze. Moreover, a positive allosteric modulator of AMPA receptors enabled immature rats to alternate at rates seen in older animals, suggesting an excitatory synaptic limitation to hippocampal maturation. We then validated the Barnes maze for juvenile rats in order to test the effects of positive AMPA receptor modulation on a goal-directed spatial memory task. Here we report the effects of the AMPA receptor modulator, CX614, on spatial learning and memory in the Barnes maze. Similar to our prior report, animals just over 3 weeks of age display substantial improvements in learning and memory performance parameters compared to animals just under 3 weeks of age. A moderate dose of CX614 enabled immature animals to move more directly to the goal location, but only after 1 day of training. This performance improvement was observed on the second day of training with drug delivery or during a memory probe trial performed without drug delivery after the second day of training. Higher doses created more search errors, especially in more mature animals. Overall, CX614 provided modest performance benefits for immature rats in a goal-directed spatial memory task.
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Affiliation(s)
| | | | | | - Diyi Chen
- Interdisciplinary Program in Neuroscience
| | | | | | | | | | - Anjali Sardana
- James Madison High School, George Mason University, Fairfax, Virginia, USA
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2
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Qneibi M, Bdir S, Bdair M, Aldwaik SA, Sandouka D, Heeh M, Idais TI. AMPA receptor neurotransmission and therapeutic applications: A comprehensive review of their multifaceted modulation. Eur J Med Chem 2024; 266:116151. [PMID: 38237342 DOI: 10.1016/j.ejmech.2024.116151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/02/2024] [Accepted: 01/11/2024] [Indexed: 02/05/2024]
Abstract
The neuropharmacological community has shown a strong interest in AMPA receptors as critical components of excitatory synaptic transmission during the last fifteen years. AMPA receptors, members of the ionotropic glutamate receptor family, allow rapid excitatory neurotransmission in the brain. AMPA receptors, which are permeable to sodium and potassium ions, manage the bulk of the brain's rapid synaptic communications. This study thoroughly examines the recent developments in AMPA receptor regulation, focusing on a shift from single chemical illustrations to a more extensive investigation of underlying processes. The complex interplay of these modulators in modifying the function and structure of AMPA receptors is the main focus, providing insight into their influence on the speed of excitatory neurotransmission. This research emphasizes the potential of AMPA receptor modulation as a therapy for various neurological disorders such as epilepsy and Alzheimer's disease. Analyzing these regulators' sophisticated molecular details enhances our comprehension of neuropharmacology, representing a significant advancement in using AMPA receptors for treating intricate neurological conditions.
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Affiliation(s)
- Mohammad Qneibi
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine.
| | - Sosana Bdir
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | - Mohammad Bdair
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | - Samia Ammar Aldwaik
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | - Dana Sandouka
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | | | - Tala Iyad Idais
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
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3
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Arnold E, Soler-Llavina G, Kambara K, Bertrand D. The importance of ligand gated ion channels in sleep and sleep disorders. Biochem Pharmacol 2023; 212:115532. [PMID: 37019187 DOI: 10.1016/j.bcp.2023.115532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023]
Abstract
On average, humans spend about 26 years of their life sleeping. Increased sleep duration and quality has been linked to reduced disease risk; however, the cellular and molecular underpinnings of sleep remain open questions. It has been known for some time that pharmacological modulation of neurotransmission in the brain can promote either sleep or wakefulness thereby providing some clues about the molecular mechanisms at play. However, the field of sleep research has developed an increasingly detailed understanding of the requisite neuronal circuitry and key neurotransmitter receptor subtypes, suggesting that it may be possible to identify next generation pharmacological interventions to treat sleep disorders within this same space. The aim of this work is to examine the latest physiological and pharmacological findings highlighting the contribution of ligand gated ion channels including the inhibitory GABAA and glycine receptors and excitatory nicotinic acetylcholine receptors and glutamate receptors in the sleep-wake cycle regulation. Overall, a better understanding of ligand gated ion channels in sleep will help determine if these highly druggable targets could facilitate a better night's sleep.
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Kiselev A, Kotov A, Mikhaleva M, Stovbun S, Kotov S. Ampakines — a promising approach to neuroprotection. Zh Nevrol Psikhiatr Im S S Korsakova 2022; 122:54-62. [DOI: 10.17116/jnevro202212209154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Kadriu B, Musazzi L, Johnston JN, Kalynchuk LE, Caruncho HJ, Popoli M, Zarate CA. Positive AMPA receptor modulation in the treatment of neuropsychiatric disorders: A long and winding road. Drug Discov Today 2021; 26:2816-2838. [PMID: 34358693 DOI: 10.1016/j.drudis.2021.07.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/12/2021] [Accepted: 07/28/2021] [Indexed: 12/13/2022]
Abstract
Glutamatergic transmission is widely implicated in neuropsychiatric disorders, and the discovery that ketamine elicits rapid-acting antidepressant effects by modulating α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) signaling has spurred a resurgence of interest in the field. This review explores agents in various stages of development for neuropsychiatric disorders that positively modulate AMPARs, both directly and indirectly. Despite promising preclinical research, few direct and indirect AMPAR positive modulators have progressed past early clinical development. Challenges such as low potency have created barriers to effective implementation. Nevertheless, the functional complexity of AMPARs sets them apart from other drug targets and allows for specificity in drug discovery. Additional effective treatments for neuropsychiatric disorders that work through positive AMPAR modulation may eventually be developed.
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Affiliation(s)
- Bashkim Kadriu
- Experimental Therapeutics & Pathophysiology Branch, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Laura Musazzi
- School of Medicine and Surgery, University of Milano-Bicocca, Italy
| | - Jenessa N Johnston
- Experimental Therapeutics & Pathophysiology Branch, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Lisa E Kalynchuk
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Hector J Caruncho
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Maurizio Popoli
- Laboratory of Neuropsychopharmacology and Functional Neurogenomics, Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Italy
| | - Carlos A Zarate
- Experimental Therapeutics & Pathophysiology Branch, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
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Gordillo-Salas M, Pascual-Antón R, Ren J, Greer J, Adell A. Antidepressant-Like Effects of CX717, a Positive Allosteric Modulator of AMPA Receptors. Mol Neurobiol 2020; 57:3498-3507. [DOI: 10.1007/s12035-020-01954-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/26/2020] [Indexed: 12/17/2022]
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Hardouin C, Pin F, Giffard JF, Hervouet Y, Hublet J, Janvier S, Penloup C, Picard J, Pinault N, Schiavi B, Zhang P, Zhao W, Zhu X. Large Scale Synthesis of an Ampakine-type Active Pharmaceutical Ingredient Based on a Telescoped Regioselective Double Amidation Reaction. Org Process Res Dev 2019. [DOI: 10.1021/acs.oprd.9b00241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Christophe Hardouin
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Frédéric Pin
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Jean-François Giffard
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Yvon Hervouet
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Julie Hublet
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Solenn Janvier
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Christine Penloup
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Julien Picard
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Nathalie Pinault
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Bruno Schiavi
- Industrial Research Centre, Oril Industrie, 13 rue Desgenétais, 76210 Bolbec, France
| | - Peng Zhang
- Shanghai Institute of Pharmaceutical Indus China State Institute of Pharmaceutical Industry, 285 Gebaini Road, Pudong District, Shanghai 201203, People’s Republic of China
| | - Weiwei Zhao
- Shanghai Institute of Pharmaceutical Indus China State Institute of Pharmaceutical Industry, 285 Gebaini Road, Pudong District, Shanghai 201203, People’s Republic of China
| | - Xueyan Zhu
- Shanghai Institute of Pharmaceutical Indus China State Institute of Pharmaceutical Industry, 285 Gebaini Road, Pudong District, Shanghai 201203, People’s Republic of China
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Phillips H, McDowell A, Mielby BS, Tucker IG, Colombo M. Aniracetam does not improve working memory in neurologically healthy pigeons. PLoS One 2019; 14:e0215612. [PMID: 31002681 PMCID: PMC6474613 DOI: 10.1371/journal.pone.0215612] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 04/04/2019] [Indexed: 01/08/2023] Open
Abstract
Understanding the effects of cognitive enhancing drugs is an important area of research. Much of the research, however, has focused on restoring memory following some sort of disruption to the brain, such as damage or injections of scopolamine. Aniracetam is a positive AMPA-receptor modulator that has shown promise for improving memory under conditions when the brain has been damaged, but its effectiveness in improving memory in neurologically healthy subjects is unclear. The aim of the present study was to examine the effects of aniracetam (100mg/kg and 200 mg/kg) on short-term memory in "neurologically healthy" pigeons. Pigeons were administered aniracetam via either intramuscular injection or orally, either 30 or 60 minutes prior to testing on a delayed matching-to-sample task. Aniracetam had no effect on the pigeons' memory performance, nor did it affect response latency. These findings add to the growing evidence that, while effective at improving memory function in models of impaired memory, aniracetam has no effect in improving memory in healthy organisms.
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Affiliation(s)
- Hannah Phillips
- Department of Psychology, University of Otago, Dunedin, Otago, New Zealand
- * E-mail: (HP); (MC)
| | - Arlene McDowell
- School of Pharmacy, University of Otago, Dunedin, Otago, New Zealand
| | | | - Ian G. Tucker
- School of Pharmacy, University of Otago, Dunedin, Otago, New Zealand
| | - Michael Colombo
- Department of Psychology, University of Otago, Dunedin, Otago, New Zealand
- * E-mail: (HP); (MC)
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Brogi S, Campiani G, Brindisi M, Butini S. Allosteric Modulation of Ionotropic Glutamate Receptors: An Outlook on New Therapeutic Approaches To Treat Central Nervous System Disorders. ACS Med Chem Lett 2019; 10:228-236. [PMID: 30891118 DOI: 10.1021/acsmedchemlett.8b00450] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 01/23/2019] [Indexed: 01/12/2023] Open
Abstract
The allosteric targeting of ionotropic glutamate receptors (iGluRs) is a valuable approach for treating various central nervous system (CNS) disorders. In this frame, this Innovations provides a summary of the state-of-the art in the development of allosteric modulators for iGluRs and offers an outlook regarding innovative strategies for treating neurological diseases.
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Affiliation(s)
- Simone Brogi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, DoE Department of Excellence 2018−2022, via Aldo Moro 2, I-53100 Siena, Italy
- Department of Pharmacy, University of Napoli Federico II, DoE Department of Excellence 2018−2022, Via D. Montesano 49, 80131 Napoli, Italy
| | - Giuseppe Campiani
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, DoE Department of Excellence 2018−2022, via Aldo Moro 2, I-53100 Siena, Italy
| | - Margherita Brindisi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, DoE Department of Excellence 2018−2022, via Aldo Moro 2, I-53100 Siena, Italy
| | - Stefania Butini
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, DoE Department of Excellence 2018−2022, via Aldo Moro 2, I-53100 Siena, Italy
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Optogenetic Stimulation of Prefrontal Glutamatergic Neurons Enhances Recognition Memory. J Neurosci 2017; 36:4930-9. [PMID: 27147648 PMCID: PMC4854963 DOI: 10.1523/jneurosci.2933-15.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 03/04/2016] [Indexed: 01/22/2023] Open
Abstract
Finding effective cognitive enhancers is a major health challenge; however, modulating glutamatergic neurotransmission has the potential to enhance performance in recognition memory tasks. Previous studies using glutamate receptor antagonists have revealed that the medial prefrontal cortex (mPFC) plays a central role in associative recognition memory. The present study investigates short-term recognition memory using optogenetics to target glutamatergic neurons within the rodent mPFC specifically. Selective stimulation of glutamatergic neurons during the online maintenance of information enhanced associative recognition memory in normal animals. This cognitive enhancing effect was replicated by local infusions of the AMPAkine CX516, but not CX546, which differ in their effects on EPSPs. This suggests that enhancing the amplitude, but not the duration, of excitatory synaptic currents improves memory performance. Increasing glutamate release through infusions of the mGluR7 presynaptic receptor antagonist MMPIP had no effect on performance. SIGNIFICANCE STATEMENT These results provide new mechanistic information that could guide the targeting of future cognitive enhancers. Our work suggests that improved associative-recognition memory can be achieved by enhancing endogenous glutamatergic neuronal activity selectively using an optogenetic approach. We build on these observations to recapitulate this effect using drug treatments that enhance the amplitude of EPSPs; however, drugs that alter the duration of the EPSP or increase glutamate release lack efficacy. This suggests that both neural and temporal specificity are needed to achieve cognitive enhancement.
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Deadwyler SA, Hampson RE, Song D, Opris I, Gerhardt GA, Marmarelis VZ, Berger TW. A cognitive prosthesis for memory facilitation by closed-loop functional ensemble stimulation of hippocampal neurons in primate brain. Exp Neurol 2016; 287:452-460. [PMID: 27233622 DOI: 10.1016/j.expneurol.2016.05.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 11/25/2022]
Abstract
Very productive collaborative investigations characterized how multineuron hippocampal ensembles recorded in nonhuman primates (NHPs) encode short-term memory necessary for successful performance in a delayed match to sample (DMS) task and utilized that information to devise a unique nonlinear multi-input multi-output (MIMO) memory prosthesis device to enhance short-term memory in real-time during task performance. Investigations have characterized how the hippocampus in primate brain encodes information in a multi-item, rule-controlled, delayed match to sample (DMS) task. The MIMO model was applied via closed loop feedback micro-current stimulation during the task via conformal electrode arrays and enhanced performance of the complex memory requirements. These findings clearly indicate detection of a means by which the hippocampus encodes information and transmits this information to other brain regions involved in memory processing. By employing the nonlinear dynamic multi-input/multi-output (MIMO) model, developed and adapted to hippocampal neural ensemble firing patterns derived from simultaneous recorded multi-neuron CA1 and CA3 activity, it was possible to extract information encoded in the Sample phase of DMS trials that was necessary for successful performance in the subsequent Match phase of the task. The extension of this MIMO model to online delivery of electrical stimulation patterns to the same recording loci that exhibited successful CA1 firing in the DMS Sample Phase provided the means to increase task performance on a trial-by-trial basis. Increased utility of the MIMO model as a memory prosthesis was exhibited by the demonstration of cumulative increases in DMS task performance with repeated MIMO stimulation over many sessions. These results, reported below in this article, provide the necessary demonstrations to further the feasibility of the MIMO model as a memory prosthesis to recover and/or enhance encoding of cognitive information in humans with memory disruptions resulting from brain injury, disease or aging.
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Lind J, Enquist M, Ghirlanda S. Animal memory: A review of delayed matching-to-sample data. Behav Processes 2015; 117:52-8. [DOI: 10.1016/j.beproc.2014.11.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 11/12/2014] [Accepted: 11/24/2014] [Indexed: 10/24/2022]
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Loomis S, McCarthy A, Baxter C, Kellett DO, Edgar DM, Tricklebank M, Gilmour G. Distinct pro-vigilant profile induced in rats by the mGluR5 potentiator LSN2814617. Psychopharmacology (Berl) 2015; 232:3977-89. [PMID: 25902875 PMCID: PMC4600478 DOI: 10.1007/s00213-015-3936-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/02/2015] [Indexed: 12/30/2022]
Abstract
While treatment options are available, excessive daytime sleepiness (EDS) remains a significant unmet medical need for many patients. Relatively little rodent behavioural pharmacology has been conducted in this context to assess potential pro-vigilant compounds for their ability to restore functional capacity following experimentally induced sleep loss. Male Wistar rats were prepared for electroencephalographic (EEG) recording and subject to 11 h of sleep restriction using a biofeedback-induced cage rotation protocol. A simple response latency task (SRLT) was used to behaviourally index sleep restriction and the effects of pro-vigilant compounds: modafinil, D-amphetamine, caffeine, and the mGlu5-positive allosteric modulator LSN2814617. Sleep restriction resulted in a consistent, quantified loss of non-rapid eye movement (NREM) and REM sleep that impaired SRLT performance in a manner suggestive of progressive task disengagement. In terms of EEG parameters, all compounds induced wakefulness. Amphetamine treatment further decreased SRLT performance capacity, whereas the other three compounds decreased omissions and allowed animals to re-engage in the task. Caffeine and modafinil also significantly increased premature responses during this period, an effect not observed for LSN2814617. While all compounds caused compensatory sleep responses, the magnitude of compensation observed for LSN2814617 was much smaller than would be predicted to result from the prolongation of wakefulness exhibited. Using simple response latencies to index performance, an mGlu5 PAM dramatically increased wakefulness and improved functional capacity of sleep-restricted animals, without eliciting a proportionate compensatory sleep response. This effect was qualitatively distinct from that of amphetamine, caffeine and modafinil.
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Affiliation(s)
- Sally Loomis
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Andrew McCarthy
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Christopher Baxter
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Daniel O. Kellett
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Dale M. Edgar
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Mark Tricklebank
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Gary Gilmour
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, England, UK.
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Pieramico V, Esposito R, Cesinaro S, Frazzini V, Sensi SL. Effects of non-pharmacological or pharmacological interventions on cognition and brain plasticity of aging individuals. Front Syst Neurosci 2014; 8:153. [PMID: 25228860 PMCID: PMC4151335 DOI: 10.3389/fnsys.2014.00153] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 08/05/2014] [Indexed: 12/21/2022] Open
Abstract
Brain aging and aging-related neurodegenerative disorders are major health challenges faced by modern societies. Brain aging is associated with cognitive and functional decline and represents the favourable background for the onset and development of dementia. Brain aging is associated with early and subtle anatomo-functional physiological changes that often precede the appearance of clinical signs of cognitive decline. Neuroimaging approaches unveiled the functional correlates of these alterations and helped in the identification of therapeutic targets that can be potentially useful in counteracting age-dependent cognitive decline. A growing body of evidence supports the notion that cognitive stimulation and aerobic training can preserve and enhance operational skills in elderly individuals as well as reduce the incidence of dementia. This review aims at providing an extensive and critical overview of the most recent data that support the efficacy of non-pharmacological and pharmacological interventions aimed at enhancing cognition and brain plasticity in healthy elderly individuals as well as delaying the cognitive decline associated with dementia.
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Affiliation(s)
- Valentina Pieramico
- Molecular Neurology Unit, Center of Excellence on Aging, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Roberto Esposito
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Stefano Cesinaro
- Molecular Neurology Unit, Center of Excellence on Aging, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Valerio Frazzini
- Molecular Neurology Unit, Center of Excellence on Aging, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Stefano L Sensi
- Molecular Neurology Unit, Center of Excellence on Aging, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy ; Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy ; Departments of Neurology and Pharmacology, Institute for Memory Impairments and Neurological Disorders, University of California-Irvine Irvine, CA, USA
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Santos L, Opris I, Hampson R, Godwin DW, Gerhardt G, Deadwyler S. Functional dynamics of primate cortico-striatal networks during volitional movements. Front Syst Neurosci 2014; 8:27. [PMID: 24653682 PMCID: PMC3947991 DOI: 10.3389/fnsys.2014.00027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 02/06/2014] [Indexed: 01/08/2023] Open
Abstract
The motor cortex and dorsal striatum (caudate nucleus and putamen) are key regions in motor processing but the interface between the cortex and striatum is not well understood. While dorsal striatum integrates information from multiple brain regions to shape motor learning and habit formation, the disruption of cortico-striatal circuits compromises the functionality of these circuits resulting in a multitude of neurologic disorders, including Parkinson's disease. To better understand the modulation of the cortico-striatal circuits we recorded simultaneously single neuron activity from four brain regions, primary motor, and sensory cortices, together with the rostral and caudal segments of the putamen in rhesus monkeys performing a visual motor task. Results show that spatial and temporal-task related firing relationships between these cortico-striatal circuit regions were modified by the independent administration of the two drugs (cocaine and baclofen). Spatial tuning and correlated firing of neurons from motor cortex and putamen were severely disrupted by cocaine and baclofen on correct trials, while the two drugs have dramatically decreased the functional connectivity of the motor cortical-striatal network. These findings provide insight into the modulation of cortical-striatal firing related to movement with implications for therapeutic approaches to Parkinson's disease and related disorders.
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Affiliation(s)
- Lucas Santos
- Department of Physiology and Pharmacology, Wake Forest University Medical School Winston-Salem, NC, USA
| | - Ioan Opris
- Department of Physiology and Pharmacology, Wake Forest University Medical School Winston-Salem, NC, USA
| | - Robert Hampson
- Department of Physiology and Pharmacology, Wake Forest University Medical School Winston-Salem, NC, USA
| | - Dwayne W Godwin
- Department of Physiology and Pharmacology, Wake Forest University Medical School Winston-Salem, NC, USA ; Department of Neurobiology and Anatomy, Wake Forest University Medical School Winston-Salem, NC, USA
| | - Greg Gerhardt
- Department of Neurobiology and Neurology, University of Kentucky Lexington, KY, USA
| | - Samuel Deadwyler
- Department of Physiology and Pharmacology, Wake Forest University Medical School Winston-Salem, NC, USA
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Hampson RE, Song D, Opris I, Santos LM, Shin DC, Gerhardt GA, Marmarelis VZ, Berger TW, Deadwyler SA. Facilitation of memory encoding in primate hippocampus by a neuroprosthesis that promotes task-specific neural firing. J Neural Eng 2013; 10:066013. [PMID: 24216292 PMCID: PMC3919468 DOI: 10.1088/1741-2560/10/6/066013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Memory accuracy is a major problem in human disease and is the primary factor that defines Alzheimer's, ageing and dementia resulting from impaired hippocampal function in the medial temporal lobe. Development of a hippocampal memory neuroprosthesis that facilitates normal memory encoding in nonhuman primates (NHPs) could provide the basis for improving memory in human disease states. APPROACH NHPs trained to perform a short-term delayed match-to-sample (DMS) memory task were examined with multi-neuron recordings from synaptically connected hippocampal cell fields, CA1 and CA3. Recordings were analyzed utilizing a previously developed nonlinear multi-input multi-output (MIMO) neuroprosthetic model, capable of extracting CA3-to-CA1 spatiotemporal firing patterns during DMS performance. MAIN RESULTS The MIMO model verified that specific CA3-to-CA1 firing patterns were critical for the successful encoding of sample phase information on more difficult DMS trials. This was validated by the delivery of successful MIMO-derived encoding patterns via electrical stimulation to the same CA1 recording locations during the sample phase which facilitated task performance in the subsequent, delayed match phase, on difficult trials that required more precise encoding of sample information. SIGNIFICANCE These findings provide the first successful application of a neuroprosthesis designed to enhance and/or repair memory encoding in primate brain.
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Affiliation(s)
- Robert E. Hampson
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Dong Song
- Department of Biomedical Engineering, University of Southern California, LA, CA
| | - Ioan Opris
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Lucas M. Santos
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Dae C. Shin
- Department of Biomedical Engineering, University of Southern California, LA, CA
| | - Greg A. Gerhardt
- Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY
| | | | - Theodore W. Berger
- Department of Biomedical Engineering, University of Southern California, LA, CA
| | - Sam A. Deadwyler
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC
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17
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Patel NC, Schwarz J, Hou XJ, Hoover DJ, Xie L, Fliri AJ, Gallaschun RJ, Lazzaro JT, Bryce DK, Hoffmann WE, Hanks AN, McGinnis D, Marr ES, Gazard JL, Hajós M, Scialis RJ, Hurst RS, Shaffer CL, Pandit J, O’Donnell CJ. Discovery and Characterization of a Novel Dihydroisoxazole Class of α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) Receptor Potentiators. J Med Chem 2013; 56:9180-91. [DOI: 10.1021/jm401274b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Nandini C. Patel
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jacob Schwarz
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Xinjun J. Hou
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Dennis J. Hoover
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Longfei Xie
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Anton J. Fliri
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Randall J. Gallaschun
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - John T. Lazzaro
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Dianne K. Bryce
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - William E. Hoffmann
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Ashley N. Hanks
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Dina McGinnis
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Eric S. Marr
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Justin L. Gazard
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Mihály Hajós
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Renato J. Scialis
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Raymond S. Hurst
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Christopher L. Shaffer
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jayvardhan Pandit
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Christopher J. O’Donnell
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
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18
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Molina DP, Ariwodola OJ, Weiner JL, Brunso-Bechtold JK, Adams MM. Growth hormone and insulin-like growth factor-I alter hippocampal excitatory synaptic transmission in young and old rats. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1575-87. [PMID: 22851280 PMCID: PMC3776110 DOI: 10.1007/s11357-012-9460-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/11/2012] [Indexed: 06/01/2023]
Abstract
In rats, as in humans, normal aging is characterized by a decline in hippocampal-dependent learning and memory, as well as in glutamatergic function. Both growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels have been reported to decrease with age, and treatment with either GH or IGF-I can ameliorate age-related cognitive decline. Interestingly, acute GH and IGF-I treatments enhance glutamatergic synaptic transmission in the rat hippocampus of juvenile animals. However, whether this enhancement also occurs in old rats, when cognitive impairment is ameliorated by GH and IGF-I (des-IGF-I), remains to be determined. To address this issue, we used an in vitro CA1 hippocampal slice preparation and extracellular recording techniques to study the effects of acute application of GH and IGF-I on compound field excitatory postsynaptic potentials (fEPSPs), as well as AMPA- and NMDA-dependent fEPSPs, in young adult (10 months) and old (28 months) rats. The results indicated that both GH and IGF-I increased compound-, AMPA-, and NMDA-dependent fEPSPs to a similar extent in slices from both age groups and that this augmentation was likely mediated via a postsynaptic mechanism. Initial characterization of the signaling cascades underlying these effects revealed that the GH-induced enhancement was not mediated by the JAK2 signaling element in either young adult or old rats but that the IGF-I-induced enhancement involved a PI3K-mediated mechanism in old, but not young adults. The present findings are consistent with a role for a GH- or IGF-I-induced enhancement of glutamatergic transmission in mitigating age-related cognitive impairment in old rats.
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Affiliation(s)
- Doris P. Molina
- />Departments of Neurobiology and Anatomy, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1010 USA
| | - Olusegun J. Ariwodola
- />Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1010 USA
| | - Jeff L. Weiner
- />Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1010 USA
| | - Judy K. Brunso-Bechtold
- />Departments of Neurobiology and Anatomy, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1010 USA
- />Roena Kulynych Center for Memory and Cognition Research, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1010 USA
| | - Michelle M. Adams
- />Departments of Neurobiology and Anatomy, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1010 USA
- />Roena Kulynych Center for Memory and Cognition Research, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1010 USA
- />Department of Psychology, Bilkent University, 06800 Bilkent, Ankara, Turkey
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19
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Lynch G, Gall CM. Mechanism based approaches for rescuing and enhancing cognition. Front Neurosci 2013; 7:143. [PMID: 23966908 PMCID: PMC3744010 DOI: 10.3389/fnins.2013.00143] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 05/23/2013] [Indexed: 01/24/2023] Open
Abstract
Progress toward pharmacological means for enhancing memory and cognition has been retarded by the widely discussed failure of behavioral studies in animals to predict human outcomes. As a result, a number of groups have targeted cognition-related neurobiological mechanisms in animal models, with the assumption that these basic processes are highly conserved across mammals. Here we survey one such approach that begins with a form of synaptic plasticity intimately related to memory encoding in animals and likely operative in humans. An initial section will describe a detailed hypothesis concerning the signaling and structural events (a “substrate map”) that convert learning associated patterns of afferent activity into extremely stable increases in fast, excitatory transmission. We next describe results suggesting that all instances of intellectual impairment so far tested in rodent models involve a common endpoint failure in the substrate map. This will be followed by a clinically plausible proposal for obviating the ultimate defect in these models. We then take up the question of whether it is reasonable to expect, from either general principles or a very limited set of experimental results, that enhancing memory will expand the cognitive capabilities of high functioning brains. The final section makes several suggestions about how to improve translation of behavioral results from animals to humans. Collectively, the material covered here points to the following: (1) enhancement, in the sense of rescue, is not an unrealistic possibility for a broad array of neuropsychiatric disorders; (2) serendipity aside, developing means for improving memory in normals will likely require integration of information about mechanisms with new behavioral testing strategies; (3) a shift in emphasis from synapses to networks is a next, logical step in the evolution of the cognition enhancement field.
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Affiliation(s)
- Gary Lynch
- Department of Psychiatry and Human Behavior, University of California Irvine, CA, USA ; Department of Anatomy and Neurobiology, University of California Irvine, CA, USA
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20
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Wright MJ, Vandewater SA, Parsons LH, Taffe MA. Δ(9)Tetrahydrocannabinol impairs reversal learning but not extra-dimensional shifts in rhesus macaques. Neuroscience 2013; 235:51-8. [PMID: 23333671 DOI: 10.1016/j.neuroscience.2013.01.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 12/19/2012] [Accepted: 01/05/2013] [Indexed: 11/24/2022]
Abstract
Expansion of medical marijuana use in the US and the recently successful decriminalization of recreational marijuana in two States elevates interest in the specific cognitive effects of Δ(9)tetrahydrocannabinol (Δ(9)THC), the major psychoactive constituent of marijuana. Controlled laboratory studies in nonhuman primates provide mixed evidence for specific effects of Δ(9)THC in learning and memory tasks, with a suggestion that frontal-mediated tasks may be the most sensitive. In this study, adult male rhesus monkeys were trained on tasks which assess reversal learning, extradimensional attentional shift learning and spatial delayed-response. Subjects were challenged with 0.1-0.5mg/kg Δ(9)THC, i.m., in randomized order and evaluated on the behavioral measures. Peak plasma levels of Δ(9)THC were observed 30min after 0.2mg/kg (69±29ng/ml) and 60min after 0.5mg/kg (121±23ng/ml) was administered and behavioral effects on a bimanual motor task persisted for up to 2h after injection. An increase in errors-to-criterion (ETC) associated with reversal learning was further increased by Δ(9)THC in a dose-dependent manner. The increase in ETC associated with extradimensional shifts was not affected by Δ(9)THC. Spatial delayed-response performance was impaired by Δ(9)THC in a retention-interval-dependent manner. Overall the pattern of results suggests a more profound effect of Δ(9)THC on tasks mediated by orbitofrontal (reversal learning) versus dorsolateral (extradimensional shifts) prefrontal mechanisms.
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Affiliation(s)
- M J Wright
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA 92037, USA
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21
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Porrino LJ, Hampson RE, Opris I, Deadwyler SA. Acute cocaine induced deficits in cognitive performance in rhesus macaque monkeys treated with baclofen. Psychopharmacology (Berl) 2013; 225:105-14. [PMID: 22836369 PMCID: PMC3801229 DOI: 10.1007/s00213-012-2798-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Accepted: 06/28/2012] [Indexed: 01/24/2023]
Abstract
RATIONALE Acute and/or chronic exposure to cocaine can affect cognitive performance, which may influence rate of recovery during treatment. OBJECTIVE Effects of the GABA-B receptor agonist baclofen were assessed for potency to reverse the negative influence of acute, pre-session, intravenous (IV) injection of cocaine on cognitive performance in Macaca mulatta nonhuman primates. METHODS Animals were trained to perform a modified delayed match to sample (DMS) task incorporating two types of trials with varying degrees of cognitive load that had different decision requirements in order to correctly utilize information retained over the delay interval. The effects of cocaine (0.2, 0.4, and 0.6 mg/kg, IV) alone and in combination with baclofen (0.29 and 0.40 mg/kg, IV) were examined with respect to sustained performance levels. Brain metabolic activity during performance of the task was assessed using PET imaged uptake of [(18) F]-fluorodeoxyglucose. RESULTS Acute cocaine injections produced a dose-dependent decline in DMS performance selective for trials of high cognitive load. The GABA-receptor agonist baclofen, co-administered with cocaine, reversed task performance back to nondrug (saline IV) control levels. Simultaneous assessment of PET-imaged brain metabolic activity in prefrontal cortex (PFC) showed alterations by cocaine compared to PFC metabolic activation in nondrug (saline, IV) control DMS sessions, but like performance, PFC activation was returned to control levels by baclofen (0.40 mg/kg, IV) injected with cocaine. CONCLUSIONS The results show that baclofen, administered at a relatively high dose, reversed the cognitive deficits produced by acute cocaine intoxication that may have implications for use in chronic drug exposure.
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Affiliation(s)
- Linda J. Porrino
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
| | - Robert E. Hampson
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
| | - Ioan Opris
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
| | - Samuel A. Deadwyler
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA; Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1083, USA
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22
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Lynch G, Kramár EA, Babayan AH, Rumbaugh G, Gall CM. Differences between synaptic plasticity thresholds result in new timing rules for maximizing long-term potentiation. Neuropharmacology 2013; 64:27-36. [PMID: 22820276 PMCID: PMC3445784 DOI: 10.1016/j.neuropharm.2012.07.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 06/28/2012] [Accepted: 07/01/2012] [Indexed: 01/25/2023]
Abstract
The fundamental observation that the temporal spacing of learning episodes plays a critical role in the efficiency of memory encoding has had little effect on either research on long-term potentiation (LTP) or efforts to develop cognitive enhancers. Here we review recent findings describing a spaced trials phenomenon for LTP that appears to be related to recent evidence that plasticity thresholds differ between synapses in the adult hippocampus. Results of tests with one memory enhancing drug suggest that the compound potently facilitates LTP via effects on 'high threshold' synapses and thus alters the temporally extended timing rules. Possible implications of these results for our understanding of LTP substrates, neurobiological contributors to the distributed practice effect, and the consequences of memory enhancement are discussed. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Gary Lynch
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-4260 USA
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Enikö A. Kramár
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Alex H. Babayan
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Gavin Rumbaugh
- Department of Neuroscience, The Scripps Research Institute, Jupiter FL 33458 USA
| | - Christine M. Gall
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697-4450 USA
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23
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Opris I, Fuqua JL, Huettl PF, Gerhardt GA, Berger TW, Hampson RE, Deadwyler SA. Closing the loop in primate prefrontal cortex: inter-laminar processing. Front Neural Circuits 2012. [PMID: 23189041 PMCID: PMC3504312 DOI: 10.3389/fncir.2012.00088] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Prefrontal cortical (PFC) activity in the primate brain emerging from minicolumnar microcircuits plays a critical role in cognitive processes dealing with executive control of behavior. However, the specific operations of columnar laminar processing in prefrontal cortex (PFC) are not completely understood. Here we show via implementation of unique microanatomical recording and stimulating arrays, that minicolumns in PFC are involved in the executive control of behavior in rhesus macaque nonhuman primates (NHPs) performing a delayed-match-to-sample (DMS) task. PFC neurons demonstrate functional interactions between pairs of putative pyramidal cells within specified cortical layers via anatomically oriented minicolumns. Results reveal target-specific, spatially tuned firing between inter-laminar (layer 2/3 and layer 5) pairs of neurons participating in the gating of information during the decision making phase of the task with differential correlations between activity in layer 2/3 and layer 5 in the integration of spatial vs. object-specific information for correct task performance. Such inter-laminar processing was exploited by the interfacing of an online model which delivered stimulation to layer 5 locations in a pattern associated with successful performance thereby closing the columnar loop externally in a manner that mimicked normal processing in the same task. These unique technologies demonstrate that PFC neurons encode and process information via minicolumns which provides a closed loop form of "executive function," hence disruption of such inter-laminar processing could form the bases for cognitive dysfunction in primate brain.
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Affiliation(s)
- Ioan Opris
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine Winston-Salem, NC, USA
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24
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Castner SA, Williams GV. Cognitive consequences of alterations in functional circuitry induced by chronic cocaine use and the potential impact for treatment. Biol Psychiatry 2012; 72:801-2. [PMID: 23083947 DOI: 10.1016/j.biopsych.2012.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 09/12/2012] [Accepted: 09/13/2012] [Indexed: 11/27/2022]
Affiliation(s)
- Stacy A Castner
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut 06511, USA.
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25
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Porter NM, Bohannon JH, Curran-Rauhut M, Buechel HM, Dowling ALS, Brewer LD, Popovic J, Thibault V, Kraner SD, Chen KC, Blalock EM. Hippocampal CA1 transcriptional profile of sleep deprivation: relation to aging and stress. PLoS One 2012; 7:e40128. [PMID: 22792227 PMCID: PMC3390348 DOI: 10.1371/journal.pone.0040128] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 06/01/2012] [Indexed: 11/18/2022] Open
Abstract
Background Many aging changes seem similar to those elicited by sleep-deprivation and psychosocial stress. Further, sleep architecture changes with age suggest an age-related loss of sleep. Here, we hypothesized that sleep deprivation in young subjects would elicit both stress and aging-like transcriptional responses. Methodology/Principal Findings F344 rats were divided into control and sleep deprivation groups. Body weight, adrenal weight, corticosterone level and hippocampal CA1 transcriptional profiles were measured. A second group of animals was exposed to novel environment stress (NES), and their hippocampal transcriptional profiles measured. A third cohort exposed to control or SD was used to validate transcriptional results with Western blots. Microarray results were statistically contrasted with prior transcriptional studies. Microarray results pointed to sleep pressure signaling and macromolecular synthesis disruptions in the hippocampal CA1 region. Animals exposed to NES recapitulated nearly one third of the SD transcriptional profile. However, the SD -aging relationship was more complex. Compared to aging, SD profiles influenced a significant subset of genes. mRNA associated with neurogenesis and energy pathways showed agreement between aging and SD, while immune, glial, and macromolecular synthesis pathways showed SD profiles that opposed those seen in aging. Conclusions/Significance We conclude that although NES and SD exert similar transcriptional changes, selective presynaptic release machinery and Homer1 expression changes are seen in SD. Among other changes, the marked decrease in Homer1 expression with age may represent an important divergence between young and aged brain response to SD. Based on this, it seems reasonable to conclude that therapeutic strategies designed to promote sleep in young subjects may have off-target effects in the aged. Finally, this work identifies presynaptic vesicular release and intercellular adhesion molecular signatures as novel therapeutic targets to counter effects of SD in young subjects.
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Affiliation(s)
- Nada M. Porter
- Department of Molecular and Biomedical Pharmacology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Julia H. Bohannon
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Meredith Curran-Rauhut
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, United States of America
| | - Heather M. Buechel
- Department of Molecular and Biomedical Pharmacology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Amy L. S. Dowling
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, United States of America
| | - Lawrence D. Brewer
- Department of Molecular and Biomedical Pharmacology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Jelena Popovic
- Department of Molecular and Biomedical Pharmacology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Veronique Thibault
- Department of Molecular and Biomedical Pharmacology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Susan D. Kraner
- Department of Neuroscience Cell Biology Physiology, Wright State University, Dayton, Ohio, United States of America
| | - Kuey Chu Chen
- Department of Molecular and Biomedical Pharmacology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Eric M. Blalock
- Department of Molecular and Biomedical Pharmacology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
- * E-mail:
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26
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Abstract
This review summarizes the brain mechanisms controlling sleep and wakefulness. Wakefulness promoting systems cause low-voltage, fast activity in the electroencephalogram (EEG). Multiple interacting neurotransmitter systems in the brain stem, hypothalamus, and basal forebrain converge onto common effector systems in the thalamus and cortex. Sleep results from the inhibition of wake-promoting systems by homeostatic sleep factors such as adenosine and nitric oxide and GABAergic neurons in the preoptic area of the hypothalamus, resulting in large-amplitude, slow EEG oscillations. Local, activity-dependent factors modulate the amplitude and frequency of cortical slow oscillations. Non-rapid-eye-movement (NREM) sleep results in conservation of brain energy and facilitates memory consolidation through the modulation of synaptic weights. Rapid-eye-movement (REM) sleep results from the interaction of brain stem cholinergic, aminergic, and GABAergic neurons which control the activity of glutamatergic reticular formation neurons leading to REM sleep phenomena such as muscle atonia, REMs, dreaming, and cortical activation. Strong activation of limbic regions during REM sleep suggests a role in regulation of emotion. Genetic studies suggest that brain mechanisms controlling waking and NREM sleep are strongly conserved throughout evolution, underscoring their enormous importance for brain function. Sleep disruption interferes with the normal restorative functions of NREM and REM sleep, resulting in disruptions of breathing and cardiovascular function, changes in emotional reactivity, and cognitive impairments in attention, memory, and decision making.
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Affiliation(s)
- Ritchie E Brown
- Laboratory of Neuroscience, VA Boston Healthcare System and Harvard Medical School, Brockton, Massachusetts 02301, USA
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Van Dam D, De Deyn PP. Animal models in the drug discovery pipeline for Alzheimer's disease. Br J Pharmacol 2012; 164:1285-300. [PMID: 21371009 DOI: 10.1111/j.1476-5381.2011.01299.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
With increasing feasibility of predicting conversion of mild cognitive impairment to dementia based on biomarker profiling, the urgent need for efficacious disease-modifying compounds has become even more critical. Despite intensive research, underlying pathophysiological mechanisms remain insufficiently documented for purposeful target discovery. Translational research based on valid animal models may aid in alleviating some of the unmet needs in the current Alzheimer's disease pharmaceutical market, which includes disease-modification, increased efficacy and safety, reduction of the number of treatment unresponsive patients and patient compliance. The development and phenotyping of animal models is indeed essential in Alzheimer's disease-related research as valid models enable the appraisal of early pathological processes - which are often not accessible in patients, and subsequent target discovery and evaluation. This review paper summarizes and critically evaluates currently available animal models, and discusses their value to the Alzheimer drug discovery pipeline. Models dealt with include spontaneous models in various species, including senescence-accelerated mice, chemical and lesion-induced rodent models, and genetically modified models developed in Drosophila melanogaster, Caenorhabditis elegans, Danio rerio and rodents. Although highly valid animal models exist, none of the currently available models recapitulates all aspects of human Alzheimer's disease, and one should always be aware of the potential dangers of uncritical extrapolating from model organisms to a human condition that takes decades to develop and mainly involves higher cognitive functions.
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Affiliation(s)
- Debby Van Dam
- Laboratory of Neurochemistry & Behaviour, Institute Born-Bunge, Department of Biomedical Sciences, University of Antwerp, Wilrijk (Antwerp), Belgium.
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28
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Santos L, Opris I, Fuqua J, Hampson RE, Deadwyler SA. A novel tetrode microdrive for simultaneous multi-neuron recording from different regions of primate brain. J Neurosci Methods 2012; 205:368-74. [PMID: 22326226 DOI: 10.1016/j.jneumeth.2012.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 01/06/2012] [Accepted: 01/09/2012] [Indexed: 11/29/2022]
Abstract
A unique custom-made tetrode microdrive for recording from large numbers of neurons in several areas of primate brain is described as a means for assessing simultaneous neural activity in cortical and subcortical structures in nonhuman primates (NHPs) performing behavioral tasks. The microdrive device utilizes tetrode technology with up to six ultra-thin microprobe guide tubes (0.1mm) that can be independently positioned, each containing reduced diameter tetrode and/or hexatrode microwires (0.02 mm) for recording and isolating single neuron activity. The microdrive device is mounted within the standard NHP cranial well and allows traversal of brain depths up to 40.0 mm. The advantages of this technology are demonstrated via simultaneously recorded large populations of neurons with tetrode type probes during task performance from a) primary motor cortex and deep brain structures (caudate-putamen and hippocampus) and b) multiple layers within the prefrontal cortex. The means to characterize interactions of well-isolated ensembles of neurons recorded simultaneously from different regions, as shown with this device, has not been previously available for application in primate brain. The device has extensive application to primate models for the detection and study of inoperative or maladaptive neural circuits related to human neurological disorders.
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Affiliation(s)
- Lucas Santos
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157-1083, USA.
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Howlett AC, Reggio PH, Childers SR, Hampson RE, Ulloa NM, Deutsch DG. Endocannabinoid tone versus constitutive activity of cannabinoid receptors. Br J Pharmacol 2012; 163:1329-43. [PMID: 21545414 DOI: 10.1111/j.1476-5381.2011.01364.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This review evaluates the cellular mechanisms of constitutive activity of the cannabinoid (CB) receptors, its reversal by inverse agonists, and discusses the pitfalls and problems in the interpretation of the research data. The notion is presented that endogenously produced anandamide (AEA) and 2-arachidonoylglycerol (2-AG) serve as autocrine or paracrine stimulators of the CB receptors, giving the appearance of constitutive activity. It is proposed that one cannot interpret inverse agonist studies without inference to the receptors' environment vis-à-vis the endocannabinoid agonists which themselves are highly lipophilic compounds with a preference for membranes. The endocannabinoid tone is governed by a combination of synthetic pathways and inactivation involving transport and degradation. The synthesis and degradation of 2-AG is well characterized, and 2-AG has been strongly implicated in retrograde signalling in neurons. Data implicating endocannabinoids in paracrine regulation have been described. Endocannabinoid ligands can traverse the cell's interior and potentially be stored on fatty acid-binding proteins (FABPs). Molecular modelling predicts that the endocannabinoids derived from membrane phospholipids can laterally diffuse to enter the CB receptor from the lipid bilayer. Considering that endocannabinoid signalling to CB receptors is a much more likely scenario than is receptor activation in the absence of agonist ligands, researchers are advised to refrain from assuming constitutive activity except for experimental models known to be devoid of endocannabinoid ligands.
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Affiliation(s)
- Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA.
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Gould RW, Porrino LJ, Nader MA. Nonhuman primate models of addiction and PET imaging: dopamine system dysregulation. Curr Top Behav Neurosci 2012; 11:25-44. [PMID: 22020537 PMCID: PMC3831150 DOI: 10.1007/7854_2011_168] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This chapter highlights the use of nonhuman primate models of cocaine addiction and the use of positron emission tomography (PET) imaging to study the role of individual differences in vulnerability and how environmental and pharmacological variables can impact cocaine abuse. The chapter will describe studies related to the dopamine (DA) neurotransmitter system, and focus primarily on the D2-like DA receptor, the DA transporter and the use of fluorodeoxyglucose to better understand the neuropharmacology of cocaine abuse. The use of nonhuman primates allows for within-subject, longitudinal studies that have provided insight into the human condition and serve as an ideal model of translational research. The combination of nonhuman primate behavior, pharmacology and state-of-the-art brain imaging using PET will provide the foundation for future studies aimed at developing behavioral and pharmacological treatments for drug addiction in humans.
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Affiliation(s)
- Robert W Gould
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, 27157-1083, USA,
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31
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Ramaswamy S, Kordower JH. Gene therapy for Huntington's disease. Neurobiol Dis 2011; 48:243-54. [PMID: 22222669 DOI: 10.1016/j.nbd.2011.12.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 12/01/2011] [Accepted: 12/14/2011] [Indexed: 12/30/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disease for which there is no cure. Therapies that are efficacious in animal models have to date shown benefit for humans. One potential powerful approach is gene therapy. The ideal method of administration of gene therapy has been hotly debated and viral vectors have provided one method of long-term and wide-spread delivery to the brain. Trophic factors to protect cells from degeneration and RNAi to reduce mutant huntingtin (mHtt) protein expression are 2 main classes of compounds that demonstrate benefit in animal models. This review will examine some commonly used adeno-associated viral (AAV) vectors and discuss some therapies that hold promise for HD.
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Affiliation(s)
- Shilpa Ramaswamy
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
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Effect of oxybutynin and imidafenacin on central muscarinic receptor occupancy and cognitive function: A monkey PET study with [11C](+)3-MPB. Neuroimage 2011; 58:1-9. [DOI: 10.1016/j.neuroimage.2011.06.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 05/19/2011] [Accepted: 06/08/2011] [Indexed: 11/21/2022] Open
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Lynch G, Palmer LC, Gall CM. The likelihood of cognitive enhancement. Pharmacol Biochem Behav 2011; 99:116-29. [PMID: 21215768 PMCID: PMC3114293 DOI: 10.1016/j.pbb.2010.12.024] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/10/2010] [Accepted: 12/16/2010] [Indexed: 12/29/2022]
Abstract
Whether drugs that enhance cognition in healthy individuals will appear in the near future has become a topic of considerable interest. We address this possibility using a three variable system (psychological effect, neurobiological mechanism, and efficiency vs. capabilities) for classifying candidates. Ritalin and modafinil, two currently available compounds, operate on primary psychological states that in turn affect cognitive operations (attention and memory), but there is little evidence that these effects translate into improvements in complex cognitive processing. A second category of potential enhancers includes agents that improve memory encoding, generally without large changes in primary psychological states. Unfortunately, there is little information on how these compounds affect cognitive performance in standard psychological tests. Recent experiments have identified a number of sites at which memory drugs could, in principle, manipulate the cell biological systems underlying the learning-related long-term potentiation (LTP) effect; this may explain the remarkable diversity of memory promoting compounds. Indeed, many of these agents are known to have positive effects on LTP. A possible third category of enhancement drugs directed specifically at integrated cognitive operations is nearly empty. From a neurobiological perspective, two plausible candidate classes have emerged that both target the fast excitatory transmission responsible for communication within cortical networks. One acts on nicotinic receptors (alpha7 and alpha4) that regulate release of the neurotransmitter glutamate while the other ('ampakines') allosterically modulates the glutamate receptors mediating the post-synaptic response (EPSCs). Brain imaging in primates has shown that ampakines expand cortical networks engaged by a complex task; coupled with behavioral data, these findings provide evidence for the possibility of generating new cognitive capabilities. Finally, we suggest that continuing advances in behavioral sciences provide new opportunities for translational work, and that discussions of the social impact of cognitive enhancers have failed to consider the distinction between effects on efficiency vs. new capabilities.
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Affiliation(s)
- Gary Lynch
- Department of Psychiatry and Human Behavior, University of California, Irvine CA 92697-4291, USA.
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Yamamoto S, Nishiyama S, Kawamata M, Ohba H, Wakuda T, Takei N, Tsukada H, Domino EF. Muscarinic receptor occupancy and cognitive impairment: a PET study with [11C](+)3-MPB and scopolamine in conscious monkeys. Neuropsychopharmacology 2011; 36:1455-65. [PMID: 21430646 PMCID: PMC3096814 DOI: 10.1038/npp.2011.31] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The muscarinic cholinergic receptor (mAChR) antagonist scopolamine was used to induce transient cognitive impairment in monkeys trained in a delayed matching to sample task. The temporal relationship between the occupancy level of central mAChRs and cognitive impairment was determined. Three conscious monkeys (Macaca mulatta) were subjected to positron emission tomography (PET) scans with the mAChR radioligand N-[(11)C]methyl-3-piperidyl benzilate ([(11)C](+)3-MPB). The scan sequence was pre-, 2, 6, 24, and 48 h post-intramuscular administration of scopolamine in doses of 0.01 and 0.03 mg/kg. Occupancy levels of mAChR were maximal 2 h post-scopolamine in cortical regions innervated primarily by the basal forebrain, thalamus, and brainstem, showing that mAChR occupancy levels were 43-59 and 65-89% in doses of 0.01 and 0.03 mg/kg, respectively. In addition, dose-dependent impairment of working memory performance was measured 2 h after scopolamine. A positive correlation between the mAChR occupancy and cognitive impairment 2 and 6 h post-scopolamine was the greatest in the brainstem (P<0.00001). Although cognitive impairment was not observed 24 h post-scopolamine, sustained mAChR occupancy (11-24%) was found with both doses in the basal forebrain and thalamus, but not in the brainstem. These results indicate that a significant degree of mAChRs occupancy is needed to produce cognitive impairment by scopolamine. Furthermore, the importance of the brainstem cholinergic system in working memory in monkey is described.
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Affiliation(s)
- Shigeyuki Yamamoto
- Osaka-Hamamatsu Joint Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Shingo Nishiyama
- Central Research Laboratory, Hamamatsu Photonics KK, Hirakuchi, Hamakita, Hamamatsu, Shizuoka, Japan
| | - Masahiro Kawamata
- Central Research Laboratory, Hamamatsu Photonics KK, Hirakuchi, Hamakita, Hamamatsu, Shizuoka, Japan
| | - Hiroyuki Ohba
- Central Research Laboratory, Hamamatsu Photonics KK, Hirakuchi, Hamakita, Hamamatsu, Shizuoka, Japan
| | - Tomoyasu Wakuda
- Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Nori Takei
- Osaka-Hamamatsu Joint Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Hideo Tsukada
- Central Research Laboratory, Hamamatsu Photonics KK, Hirakuchi, Hamakita, Hamamatsu, Shizuoka, Japan
| | - Edward F Domino
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA,Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109-05632, USA, Tel: +1 734 764 9115, Fax: +1 734 763 4450, E-mail:
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Robbins ME, Bourland JD, Cline JM, Wheeler KT, Deadwyler SA. A model for assessing cognitive impairment after fractionated whole-brain irradiation in nonhuman primates. Radiat Res 2011; 175:519-25. [PMID: 21275607 DOI: 10.1667/rr2497.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To investigate the effect of fractionated whole-brain irradiation on nonhuman primates, 6-9-year-old male rhesus monkeys were irradiated with 40 Gy delivered as two 5-Gy fractions/week for 4 weeks. Cognitive function was assessed 5 days/week for 4 months prior to fractionated whole-brain irradiation and for 11 months after irradiation using a Delayed-Match-to-Sample (DMS) task at both low and high cognitive loads. Local rates of cerebral glucose metabolism were measured prior to and 9 months after irradiation using [(18)F]-2-deoxy-2-fluoro-d-glucose positron emission tomography. Low cognitive load trials did not reveal a significant reduction in performance until 7 months after irradiation; performance then declined progressively. In high cognitive load trials, the initial impairment was observed ∼1 month after irradiation. This was followed by a transient recovery period over the next 1-2 months, after which performance declined progressively through 11 months after irradiation. Nine months after irradiation, glucose uptake during the DMS task was decreased in the cuneate and prefrontal cortex and was increased in the cerebellum and thalamus compared with the levels prior to irradiation. Results from this pilot study suggest that the radiation-induced changes in cognition and brain metabolism observed in rhesus monkeys may be similar to those observed in brain tumor patients receiving brain irradiation.
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Affiliation(s)
- Mike E Robbins
- Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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Effects of cocaine rewards on neural representations of cognitive demand in nonhuman primates. Psychopharmacology (Berl) 2011; 213:105-18. [PMID: 20865250 PMCID: PMC3126099 DOI: 10.1007/s00213-010-2017-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 09/03/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE Investigations of the neural consequences of the effects of cocaine on cognition have centered on specific brain circuits including prefrontal cortex, medial temporal lobe and striatum and their roles in controlling drug dependent behavior and addiction. These regions are critical to many aspects of drug abuse; however recent investigations in addicted individuals have reported possible cognitive deficits that impact recovery and other therapeutic interventions. OBJECTIVES Therefore a direct assessment of the effects of cocaine as a reward for cognitive function provides a means of determining how brain systems involved such as prefrontal cortex are affected under normal vs. conditions of acute drug exposure as a precursor to the final impaired function in the addicted state. METHODS Nonhuman primates (NHPs) were tested in a delayed-match-to-sample decision making task to determine effects of high vs. low cognitive load trials on single neuron activity and fluorodeoxyglucose-positron emission tomography (FDG-PET) determined metabolic activation of prefrontal cortex when juice vs. intravenous cocaine were employed as rewards for successful performance. RESULTS Cognitive processing in prefrontal cortex was altered primarily on high load trials in which cocaine was randomly presented as the signaled and delivered reward on particular trials. The detrimental actions of cocaine rewards were also shown to persist and impair task performance on subsequent juice rewarded trials. CONCLUSIONS The findings indicate that one of the ways in which cocaine use may disrupt performance of a cognitive task is to alter neural processing in prefrontal cortex when involved in discriminating circumstances on the basis of low vs. high cognitive demand.
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Ji W, Ha I. Drug development for Alzheimer's disease: recent progress. Exp Neurobiol 2010; 19:120-31. [PMID: 22110351 PMCID: PMC3214787 DOI: 10.5607/en.2010.19.3.120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 12/28/2010] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease, the most common cause of dementia, is characterized by two major pathological hallmarks: amyloid plaques and neurofibrillary tangles. Based on these two indicators, an amyloid cascade hypothesis was proposed, and accordingly, most current therapeutic approaches are now focused on the removal of β-amyloid peptides (Aβ from the brain. Additionally, strategies for blocking tau hyperphosphorylation and aggregation have been suggested, including the development of drugs that can block the formation of tangles. However, there are no true disease-modifying drugs in the current market, though many drugs based on theories other than Aβ and tau pathology are under development. The purpose of this review was to provide information on the current development of AD drugs and to discuss the issues related to drug development.
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Affiliation(s)
- Wonjin Ji
- Institute for Brain Science and Technology (IBST)/Graduate Program in Neuroscience, Inje University, Busan 614-735, Korea
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Prevention of ketamine-induced working memory impairments by AMPA potentiators in a nonhuman primate model of cognitive dysfunction. Behav Brain Res 2010; 212:41-8. [DOI: 10.1016/j.bbr.2010.03.039] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 02/27/2010] [Accepted: 03/19/2010] [Indexed: 12/15/2022]
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39
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Blalock EM, Grondin R, Chen KC, Thibault O, Thibault V, Pandya JD, Dowling A, Zhang Z, Sullivan P, Porter NM, Landfield PW. Aging-related gene expression in hippocampus proper compared with dentate gyrus is selectively associated with metabolic syndrome variables in rhesus monkeys. J Neurosci 2010; 30:6058-71. [PMID: 20427664 PMCID: PMC3155249 DOI: 10.1523/jneurosci.3956-09.2010] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 02/15/2010] [Accepted: 03/21/2010] [Indexed: 11/21/2022] Open
Abstract
Age-dependent metabolic syndrome (MetS) is a well established risk factor for cardiovascular disease, but it also confers major risk for impaired cognition in normal aging or Alzheimer's disease (AD). However, little is known about the specific pathways mediating MetS-brain interactions. Here, we performed the first studies quantitatively linking MetS variables to aging changes in brain genome-wide expression and mitochondrial function. In six young adult and six aging female rhesus monkeys, we analyzed gene expression in two major hippocampal subdivisions critical for memory/cognitive function [hippocampus proper, or cornu ammonis (CA), and dentate gyrus (DG)]. Genes that changed with aging [aging-related genes (ARGs)] were identified in each region. Serum variables reflecting insulin resistance and dyslipidemia were used to construct a quantitative MetS index (MSI). This MSI increased with age and correlated negatively with hippocampal mitochondrial function (state III oxidation). More than 2000 ARGs were identified in CA and/or DG, in approximately equal numbers, but substantially more ARGs in CA than in DG were correlated selectively with the MSI. Pathways represented by MSI-correlated ARGs were determined from the Gene Ontology Database and literature. In particular, upregulated CA ARGs representing glucocorticoid receptor (GR), chromatin assembly/histone acetyltransferase, and inflammatory/immune pathways were closely associated with the MSI. These results suggest a novel model in which MetS is associated with upregulation of hippocampal GR-dependent transcription and epigenetic coactivators, contributing to decreased mitochondrial function and brain energetic dysregulation. In turn, these MSI-associated neuroenergetic changes may promote inflammation, neuronal vulnerability, and risk of cognitive impairment/AD.
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Affiliation(s)
- Eric M Blalock
- Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, Kentucky 40536, USA.
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