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Individual recognition and long-term memory of inanimate interactive agents and humans in dogs. Anim Cogn 2022; 25:1427-1442. [PMID: 35513745 PMCID: PMC9652224 DOI: 10.1007/s10071-022-01624-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/30/2022] [Accepted: 04/05/2022] [Indexed: 11/26/2022]
Abstract
Investigation of individual recognition (IR) is difficult due to the lack of proper control of cues and previous experiences of subjects. Utilization of artificial agents (Unidentified Moving Objects: UMOs) may offer a better approach than using conspecifics or humans as partners. In Experiment 1, we investigated whether dogs are able to develop IR of UMOs (that is stable for at least 24 h) or that they only retain a more generalised memory about them. The UMO helped dogs to obtain an unreachable ball and played with them. One day, one week or one month later, we tested whether dogs display specific behaviour toward the familiar UMO over unfamiliar ones (four-way choice test). Dogs were also re-tested in the same helping context and playing interaction. Subjects did not approach the familiar UMO sooner than the others; however, they gazed at the familiar UMO earlier during re-testing of the problem solving task, irrespectively of the delay. In Experiment 2, we repeated the same procedure with human partners, applying a two-way choice test after a week delay, to study whether lack of IR was specific to the UMO. Dogs did not approach the familiar human sooner than the unfamiliar, but they gazed at the familiar partner earlier during re-testing. Thus, dogs do not seem to recognise an individual UMO or human after a short experience, but they remember the interaction with the novel partner in general, even after a long delay. We suggest that dogs need more experience with a specific social partner for the development of long-term memory.
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Luteolin Attenuates Cognitive Dysfunction Induced By Chronic Cerebral Hypoperfusion Through the Modulation of The PI3K/Akt Pathway in Rats. J Vet Res 2021; 65:341-349. [PMID: 34917848 PMCID: PMC8643096 DOI: 10.2478/jvetres-2021-0037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 06/16/2021] [Indexed: 11/30/2022] Open
Abstract
Introduction In our study, we evaluated the beneficial effect of luteolin in the treatment of cognitive dysfunction in rat models induced by cerebral hypoperfusion by two-vessel occlusion (2-VO). Material and Methods Seventy-five male Sprague Dawley rats were subjected to 2-VO surgery, in all but 15 (the sham group, group I) the ligation being permanent to impair cognitive abilities. The sham group rats received saline instead of a drug; 15 2-VO rats were not injected at all (the model group, group II); 15 2-VO rats were administered luteolin at 50 mg/kg b.w. (the lut 50 group, group III); to a further 15 luteolin was given at 100 mg/kg b.w. (the lut 100 group, group IV); and the final 15 received nimodipine at 16 mg/kg b.w. as positive controls (the nimodipine group, group V). Object recognition and Morris water maze tests were performed to investigate memory ability. A Western blot test was also conducted to assess expression of phosphatidylinositol 3-kinase (PI3K), its downstream target protein kinase B (Akt), and the phosphorylated form (P-Akt) in cerebral cortex and hippocampus tissue samples. Results Significant variations in the discrimination index in the object recognition test, the escape latencies in the Morris water maze test, and expression levels of PI3K-p110α and PI3K-p85 were observed three months after 2-VO surgery in both lut groups, with a significant change in the nimodipine group compared to the model group. P-Akt and Akt were expressed significantly higher in both lut groups and the nimodipine group than in the model group. Conclusion Luteolin treatment of rats cognitively dysfunctional after experimental cerebral hypo perfusion was neuroprotective by activating the PI3K/Akt signals which inhibit neuronal death in the cerebral cortex and hippocampal region.
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Gruen ME, Foster ML, Lazarowski L, Jeffries A, Sherman BL, Dorman DC. Does the cognitive bias test in dogs depend on spatial learning? J Vet Behav 2019. [DOI: 10.1016/j.jveb.2019.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lakstygal AM, Kolesnikova TO, Khatsko SL, Zabegalov KN, Volgin AD, Demin KA, Shevyrin VA, Wappler-Guzzetta EA, Kalueff AV. DARK Classics in Chemical Neuroscience: Atropine, Scopolamine, and Other Anticholinergic Deliriant Hallucinogens. ACS Chem Neurosci 2019; 10:2144-2159. [PMID: 30566832 DOI: 10.1021/acschemneuro.8b00615] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Anticholinergic drugs based on tropane alkaloids, including atropine, scopolamine, and hyoscyamine, have been used for various medicinal and toxic purposes for millennia. These drugs are competitive antagonists of acetylcholine muscarinic (M-) receptors that potently modulate the central nervous system (CNS). Currently used clinically to treat vomiting, nausea, and bradycardia, as well as alongside other anesthetics to avoid vagal inhibition, these drugs also evoke potent psychotropic effects, including characteristic delirium-like states with hallucinations, altered mood, and cognitive deficits. Given the growing clinical importance of anti-M deliriant hallucinogens, here we discuss their use and abuse, clinical importance, and the growing value in preclinical (experimental) animal models relevant to modeling CNS functions and dysfunctions.
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Affiliation(s)
- Anton M. Lakstygal
- Graduate School of Biology, St. Petersburg State University, St. Petersburg 199034, Russia
| | | | | | | | - Andrey D. Volgin
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, St. Petersburg 197341, Russia
| | - Konstantin A. Demin
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, St. Petersburg 197341, Russia
- Institute of Translational Biomedicine (ITBM), St. Petersburg State University, St. Petersburg 199034, Russia
| | | | | | - Allan V. Kalueff
- School of Pharmacy, Southwest University, Chongqing 400700, China
- Anatomy and Physiology Laboratory, Ural Federal University, Ekaterinburg 620002, Russia
- Laboratory of Biological Psychiatry, ITBM, St Petersburg State University, St. Petersburg 199034, Russia
- Scientific Research Institute of Physiology and Basic Medicine, Novosibirsk 630117, Russia
- Granov Russian Scientific Center of Radiology and Surgical Technologies, Ministry of Healthcare of Russian Federation, St. Petersburg 197758, Russia
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What do dogs (Canis familiaris) see? A review of vision in dogs and implications for cognition research. Psychon Bull Rev 2019; 25:1798-1813. [PMID: 29143248 DOI: 10.3758/s13423-017-1404-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Over the last 20 years, a large amount of research has been conducted in an attempt to uncover the cognitive abilities of the domestic dog. While substantial advancements have been made, progress has been impeded by the fact that little is known about how dogs visually perceive their external environment. It is imperative that future research determines more precisely canine visual processing capabilities, particularly considering the increasing number of studies assessing cognition via paradigms requiring vision. This review discusses current research on visual cognition and emphasizes the importance of understanding dog visual processing. We review several areas of vision research in domestic dogs, such as sensitivity to light, visual perspective, visual acuity, form perception, and color vision, with a focus on how these abilities may affect performance in cognition tasks. Additionally, we consider the immense diversity seen in dog morphology and explore ways in which these physical differences, particularly in facial morphology, may result in, or perhaps even be caused by, different visual processing capacities in dogs. Finally, we suggest future directions for research in dog vision and cognition.
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Abstract
A malamute-husky mixed-breed dog was trained to distinguish one object that differed from three others that were identical to each other. The dog progressed rapidly after an effective shaping procedure, requiring 37 training sessions to master 20 such problems to a criterion of 90 %. The dog subsequently scored 80 % correct on the first trials with new problems that required a reversal of previously correct choices. The dog then scored 70 % correct on his first trials with 20 new problems composed of entirely new objects. Both performances are far above chance. Consequently, we conclude that choosing the odd or least numerous object in a group is within the capacity of the domestic dog.
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Shin CW, Kim GA, Park WJ, Park KY, Jeon JM, Oh HJ, Kim MJ, Lee BC. Learning, memory and exploratory similarities in genetically identical cloned dogs. J Vet Sci 2016; 17:563-567. [PMID: 27030191 PMCID: PMC5204035 DOI: 10.4142/jvs.2016.17.4.563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 02/24/2016] [Accepted: 03/04/2016] [Indexed: 11/26/2022] Open
Abstract
Somatic cell nuclear transfer allows generation of genetically identical animals using donor cells derived from animals with particular traits. To date, few studies have investigated whether or not these cloned dogs will show identical behavior patterns. To address this question, learning, memory and exploratory patterns were examined using six cloned dogs with identical nuclear genomes. The variance of total incorrect choice number in the Y-maze test among cloned dogs was significantly lower than that of the control dogs. There was also a significant decrease in variance in the level of exploratory activity in the open fields test compared to age-matched control dogs. These results indicate that cloned dogs show similar cognitive and exploratory patterns, suggesting that these behavioral phenotypes are related to the genotypes of the individuals.
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Affiliation(s)
- Chi Won Shin
- Department of Veterinary Medicine, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Geon A Kim
- Department of Theriogenology & Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Won Jun Park
- Department of Veterinary Medicine, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Kwan Yong Park
- Department of Physics and Astronomy, Dana and David Dornsife College of Letters, Arts and Science, University of Southern California, Los Angeles, CA90089, USA
| | - Jeong Min Jeon
- Department of Statistics, College of Natural Science, Seoul National University, Seoul 08826, Korea
| | - Hyun Ju Oh
- Department of Theriogenology & Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Min Jung Kim
- Department of Theriogenology & Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Byeong Chun Lee
- Department of Theriogenology & Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
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Korpi ER, den Hollander B, Farooq U, Vashchinkina E, Rajkumar R, Nutt DJ, Hyytiä P, Dawe GS. Mechanisms of Action and Persistent Neuroplasticity by Drugs of Abuse. Pharmacol Rev 2015; 67:872-1004. [DOI: 10.1124/pr.115.010967] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Brain Network Activation (BNA) reveals scopolamine-induced impairment of visual working memory. J Mol Neurosci 2014; 54:59-70. [PMID: 24535560 DOI: 10.1007/s12031-014-0250-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 01/22/2014] [Indexed: 12/29/2022]
Abstract
The overarching goal of this event-related potential (ERP) study was to examine the effects of scopolamine on the dynamics of brain network activation using a novel ERP network analysis method known as Brain Network Activation (BNA). BNA was used for extracting group-common stimulus-activated network patterns elicited to matching probe stimuli in the context of a delayed matching-to-sample task following placebo and scopolamine treatments administered to healthy participants. The BNA extracted networks revealed the existence of two pathophysiological mechanisms following scopolamine, disconnection, and compensation. Specifically, weaker frontal theta and parietal alpha coupling was accompanied with enhanced fronto-centro-parietal theta activation relative to placebo. In addition, using the characteristic BNA network of each treatment as well as corresponding literature-guided selective subnetworks as combined biomarkers managed to differentiate between individual responses to each of the treatments. Behavioral effects associated with scopolamine included delayed response time and impaired response accuracy. These results indicate that the BNA method is sensitive to the effects of scopolamine on working memory and that it may potentially enable diagnosis and treatment assessment of dysfunctions associated with cholinergic deficiency.
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Concentrations of platelet α2-adrenoceptors, lymphocyte muscarinic receptors, and blood monoamines in dogs (Canis familiaris) affected by canine cognitive dysfunction syndrome. J Vet Behav 2013. [DOI: 10.1016/j.jveb.2012.06.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Bensky MK, Gosling SD, Sinn DL. The World from a Dog’s Point of View. ADVANCES IN THE STUDY OF BEHAVIOR 2013. [DOI: 10.1016/b978-0-12-407186-5.00005-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Relevance of animal models of subarachnoid hemorrhage for examining neurobehavioral changes. ACTA NEUROCHIRURGICA. SUPPLEMENT 2013; 115:225-32. [PMID: 22890673 DOI: 10.1007/978-3-7091-1192-5_41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND PURPOSE For many years survival and neurological functionality of patients were the main outcome measures after treatment of intracranial aneurysms. But, the variable outcomes of patients operated on in a delayed fashion or before the aneurysm rupture indicate that more precise measures are needed for assessment of not only the neurological but also the neuropsychological outcome. However, development and testing of such new tools requires better understanding of pathomechanisms of neurobehavioral changes evoked by aneurysmal subarachnoid hemorrhage (aSAH), which can be achieved using animal models. METHODS We reviewed and selected (1) animal models developed to investigate delayed cerebral vasospasm that could be useful for examining effects of brain injury evoked by aSAH and (2) a battery of neurobehavioral animal testing that can be used for assessment of patients after aSAH. RESULTS For every species used as an aSAH model, a battery of neurobehavioral test exists. CONCLUSION Albeit some limitations must be recognized, research using animal models of SAH should continue to play a critical role in assessment of cognitive and behavioral functions after aSAH.
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Landsberg GM, Nichol J, Araujo JA. Cognitive Dysfunction Syndrome. Vet Clin North Am Small Anim Pract 2012; 42:749-68, vii. [DOI: 10.1016/j.cvsm.2012.04.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Landsberg GM, Deporter T, Araujo JA. Clinical signs and management of anxiety, sleeplessness, and cognitive dysfunction in the senior pet. Vet Clin North Am Small Anim Pract 2012; 41:565-90. [PMID: 21601747 DOI: 10.1016/j.cvsm.2011.03.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Physical signs of old age may be obvious, but mental and cognitive changes require more careful observation. Changes in behavior may represent the earliest indications of medical problems, or disorders of the central nervous system, and these may be bidirectional. Cognitive dysfunction syndrome is underdiagnosed and affects a substantial portion of aged companion animals. This article describes potential treatment regimens to address age-related behavioral problems, as well as a framework for investigating differential diagnoses. Early identification of changes in behavior is essential for the adequate treatment and management of medical and behavioral problems, and for monitoring outcomes.
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Affiliation(s)
- Gary M Landsberg
- North Toronto Animal Clinic, 99 Henderson Avenue, Thornhill, ON L3T 2K9, Canada.
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Araujo JA, Greig NH, Ingram DK, Sandin J, de Rivera C, Milgram NW. Cholinesterase inhibitors improve both memory and complex learning in aged beagle dogs. J Alzheimers Dis 2012; 26:143-55. [PMID: 21593569 DOI: 10.3233/jad-2011-110005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Similar to patients with Alzheimer's disease (AD), dogs exhibit age-dependent cognitive decline, amyloid-β (Aβ) pathology, and evidence of cholinergic hypofunction. The present study sought to further investigate the role of cholinergic hypofunction in the canine model by examining the effect of the cholinesterase inhibitors phenserine and donepezil on performance of two tasks, a delayed non-matching-to-position task (DNMP) designed to assess working memory, and an oddity discrimination learning task designed to assess complex learning, in aged dogs. Phenserine (0.5 mg/kg; PO) significantly improved performance on the DNMP at the longest delay compared to wash-out and partially attenuated scopolamine-induced deficits (15 μg/kg; SC). Phenserine also improved learning on a difficult version of an oddity discrimination task compared to placebo, but had no effect on an easier version. We also examined the effects of three doses of donepezil (0.75, 1.5, and 6 mg/kg; PO) on performance of the DNMP. Similar to the results with phenserine, 1.5 mg/kg of donepezil improved performance at the longest delay compared to baseline and wash-out, indicative of memory enhancement. These results further extend the findings of cholinergic hypofunction in aged dogs and provide pharmacological validation of the canine model with a cholinesterase inhibitor approved for use in AD. Collectively, these studies support utilizing the aged dog in future screening of therapeutics for AD, as well as for investigating the links among cholinergic function, Aβ pathology, and cognitive decline.
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Affiliation(s)
- Joseph A Araujo
- Department of Pharmacology, University of Toronto, Toronto, ON, Canada.
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Liem-Moolenaar M, de Boer P, Timmers M, Schoemaker RC, van Hasselt JGC, Schmidt S, van Gerven JMA. Pharmacokinetic-pharmacodynamic relationships of central nervous system effects of scopolamine in healthy subjects. Br J Clin Pharmacol 2011; 71:886-98. [PMID: 21306419 DOI: 10.1111/j.1365-2125.2011.03936.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • The cholinergic system is important for different central nervous system functions, including memory, learning and attention. Scopolamine, a centrally active muscarinic antagonist, has been used to model dementia and to demonstrate the pharmacological effects of cholinergic drugs, but for most effects the concentration-effect relationships are unknown. WHAT THIS STUDY ADDS • We determined the pharmacokinetic-pharmacodynamic relationships of scopolamine using a multidimensional central nervous system test battery in a large group of healthy volunteers. The results suggested there are various functional cholinergic systems with different pharmacological characteristics, which can be used to study the effects of drugs that directly or indirectly modify cholinergic systems. The design of such studies should take the different concentration-effect relationships into account. AIM(S) Although scopolamine is a frequently used memory impairment model, the relationships between exposure and corresponding central nervous system (CNS) effects are mostly unknown. The aim of our study was to characterize these using pharmacokinetic-pharmacodynamic (PK-PD) modelling. METHODS In two double-blind, placebo-controlled, four-way crossover studies, 0.5-mg scopolamine was administered i.v. to 90 healthy male subjects. PK and PD/safety measures were monitored pre-dose and up to 8.5 h after administration. PK-PD relationships were modelled using non-linear mixed-effect modelling. RESULTS Most PD responses following scopolamine administration in 85 subjects differed significantly from placebo. As PD measures lagged behind the plasma PK profile, PK-PD relationships were modelled using an effect compartment and arbitrarily categorized according to their equilibration half-lives (t(1/2) k(eo) ; hysteresis measure). t(1/2) k(eo) for heart rate was 17 min, saccadic eye movements and adaptive tracking 1-1.5 h, body sway, smooth pursuit, visual analogue scales alertness and psychedelic 2.5-3.5 h, pupil size, finger tapping and visual analogue scales feeling high more than 8 h. CONCLUSIONS Scopolamine affected different CNS functions in a concentration-dependent manner, which based on their distinct PK-PD characteristics seemed to reflect multiple distinct functional pathways of the cholinergic system. All PD effects showed considerable albeit variable delays compared with plasma concentrations. The t(1/2) k(eo) of the central effects was longer than of the peripheral effects on heart rate, which at least partly reflects the long CNS retention of scopolamine, but possibly also the triggering of independent secondary mechanisms. PK-PD analysis can optimize scopolamine administration regimens for future research and give insight into the physiology and pharmacology of human cholinergic systems.
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Araujo JA, Nobrega JN, Raymond R, Milgram NW. Aged dogs demonstrate both increased sensitivity to scopolamine impairment and decreased muscarinic receptor density. Pharmacol Biochem Behav 2011; 98:203-9. [DOI: 10.1016/j.pbb.2011.01.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 12/22/2010] [Accepted: 01/07/2011] [Indexed: 11/29/2022]
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Landsberg GM, Denenberg S, Araujo JA. Cognitive dysfunction in cats: a syndrome we used to dismiss as 'old age'. J Feline Med Surg 2011; 12:837-48. [PMID: 20974401 DOI: 10.1016/j.jfms.2010.09.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PRACTICAL RELEVANCE Cognitive dysfunction syndrome (CDS) is a widely accepted diagnosis in dogs, with established treatment options. In cats, however, our understanding of cognitive dysfunction is still being shaped by ongoing research in the field, and limited treatment options are available. Recent clinical studies indicate that old age in the cat is accompanied by increased behavioural signs such as wandering, vocalization and night-time activity that are not attributable to identifiable medical problems. It is essential, therefore, that veterinarians include behavioural well-being in the routine care of senior cats. PATIENT GROUP While the exact age of onset is not established, studies suggest that age-related behavioural changes consistent with cognitive dysfunction are prevalent in cats as early as 10 years of age and that prevalence increases significantly in older cats. CLINICAL CHALLENGES The diagnosis of cognitive dysfunction requires the identification of geriatric behavioural changes that are not caused by other medical problems, although the two may not be mutually exclusive. Therefore, the practitioner must rely heavily on owner reports and history to ensure prompt diagnosis and treatment. The absence of any approved dietary or pharmaceutical interventions for cognitive dysfunction adds a further challenge, although several possibilities exist. EVIDENCE BASE This article draws on recent research that has produced neuropathological, cognitive and behavioural evidence for cognitive dysfunction in aging cats. As an impetus to further our understanding of this disease and potential treatment options, the authors propose a behavioural checklist that might aid in the clinical diagnosis of feline CDS and discuss treatment options that have proven successful in the canine counterpart of this disease.
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Affiliation(s)
- Gary M Landsberg
- North Toronto Animal Clinic, Thornhill, Ontario L3T 2K9, Canada.
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Kornum BR, Knudsen GM. Cognitive testing of pigs (Sus scrofa) in translational biobehavioral research. Neurosci Biobehav Rev 2011; 35:437-51. [DOI: 10.1016/j.neubiorev.2010.05.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 05/19/2010] [Accepted: 05/20/2010] [Indexed: 11/16/2022]
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Kulkarni KS, Kasture S, Mengi S. Efficacy study of Prunus amygdalus (almond) nuts in scopolamine-induced amnesia in rats. Indian J Pharmacol 2010; 42:168-73. [PMID: 20871769 PMCID: PMC2937319 DOI: 10.4103/0253-7613.66841] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 02/25/2010] [Accepted: 06/09/2010] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Cognitive disorders such as amnesia, attention deficit and Alzheimer's disease are emerging nightmares in the field of medicine because no exact cure exists for them, as existing nootropic agents (piractam, tacrine, metrifonate) have several limitations. The present study was undertaken to investigate the effect of Prunus amygdalus (PA) nuts on cognitive functions, total cholesterol levels and cholinesterase (ChE) activity in scopolamine-induced amnesia in rats. MATERIALS AND METHODS The paste of PA nuts was administered orally at three doses (150, 300 and 600 mg/kg) for 7 and 14 consecutive days to the respective groups of rats. Piracetam (200 mg/kg) was used as a standard nootropic agent. Learning and memory parameters were evaluated using elevated plus maze (EPM), passive avoidance and motor activity paradigms. Brain ChE activity and serum biochemical parameters like total cholesterol, total triglycerides and glucose were evaluated. RESULTS It was observed that PA at the above-mentioned doses after 7 and 14 days of administration in the respective groups significantly reversed scopolamine (1 mg/kg i.p.)-induced amnesia, as evidenced by a decrease in the transfer latency in the EPM task and step-down latency in the passive avoidance task. PA reduced the brain ChE activity in rats. PA also exhibited a remarkable cholesterol and triglyceride lowering property and slight increase in glucose levels in the present study. CONCLUSION Because diminished cholinergic transmission and increase in cholesterol levels appear to be responsible for the development of amyloid plaques and dementia in Alzheimer patients, PA may prove to be a useful memory-restorative agent. It would be worthwhile to explore the potential of this plant in the management of Alzheimer's disease.
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Affiliation(s)
- Kirti S. Kulkarni
- Department of Pharmacology, C. U. College of Pharmacy, SNDT Women’s University, Santacruz (W), Mumbai, India
| | - S.B. Kasture
- Department of Pharmacology, Sanjeevani College of Pharmaceutical Education and Research, Kopargaon, Dist. Ahmednagar, Maharashtra, India
| | - S.A. Mengi
- Department of Pharmacology, C. U. College of Pharmacy, SNDT Women’s University, Santacruz (W), Mumbai, India
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Jeon H, Ai J, Sabri M, Tariq A, Shang X, Chen G, Macdonald RL. Neurological and neurobehavioral assessment of experimental subarachnoid hemorrhage. BMC Neurosci 2009; 10:103. [PMID: 19706182 PMCID: PMC2749856 DOI: 10.1186/1471-2202-10-103] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 08/25/2009] [Indexed: 01/14/2023] Open
Abstract
About 50% of humans with aneurysmal subarachnoid hemorrhage (SAH) die and many survivors have neurological and neurobehavioral dysfunction. Animal studies usually focused on cerebral vasospasm and sometimes neuronal injury. The difference in endpoints may contribute to lack of translation of treatments effective in animals to humans. We reviewed prior animal studies of SAH to determine what neurological and neurobehavioral endpoints had been used, whether they differentiated between appropriate controls and animals with SAH, whether treatment effects were reported and whether they correlated with vasospasm. Only a few studies in rats examined learning and memory. It is concluded that more studies are needed to fully characterize neurobehavioral performance in animals with SAH and assess effects of treatment.
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Affiliation(s)
- Hyojin Jeon
- Division of Neurosurgery, St. Michael's Hospital, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael's Hospital and Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
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Abstract
Many treatment options are now available for pets with age-related cognitive dysfunction, including drugs, nutritional supplements, and diets. This article describes the theory, evidence of efficacy, and potential neuroprotective effects of products used to treat cognitive dysfunction. Cognitive dysfunction is a diagnosis of exclusion, because many painful conditions and health problems may present with similar signs. Practitioners must, therefore, actively question owners of senior pets in order to diagnose cognitive dysfunction and to assess the pet’s general health and well-being.
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Affiliation(s)
- Gary Landsberg
- Doncaster Animal Clinic, 99 Henderson Avenue, Thornhill, Ontario, L3T 2K9, Canada
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Kimotsuki T, Yasuda M, Tamahara S, Tomihari M, Matsuki N, Ono K. Age-Associated Changes of Flash Visual Evoked Potentials in Dogs. J Vet Med Sci 2006; 68:79-82. [PMID: 16462123 DOI: 10.1292/jvms.68.79] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Age-associated changes of visual evoked potentials by flash stimulation (flash VEP) were evaluated in 53 beagle dogs aged from 1- to 15-year-old. Among the components of flash VEP consisted of 3 positive (P1, P2 and P3) and 2 negative (N1 and N2) peaks by 150 msec, the latency of P2 and the later peaks (N2 and P3) were significantly delayed with aging. Both amplitudes of the P2-N2 and N2-P3 also showed a significant correlation with aging. The flash VEP is considered to be an available and useful technique to evaluate not only for visual pathway, but also some disturbance of neurological functions, like as those reported in demented human.
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Affiliation(s)
- Tomofumi Kimotsuki
- Medicinal Safety Research Laboratories, Sankyo Co., Ltd., Fukuroi, Shizuoka 437-0065, Japan
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Abstract
Aging pets often suffer a decline in cognitive function (eg, memory,learning, perception, awareness) likely associated with age-dependent brain alterations. Clinically, cognitive dysfunction may result in various behavioral signs, including disorientation; forgetting of previously learned behaviors, such as house training; alterations in the manner in which the pet interacts with people or other pets;onset of new fears and anxiety; decreased recognition of people, places, or pets; and other signs of deteriorating memory and learning ability. Many medical problems, including other forms of brain pathologic conditions, can contribute to these signs. The practitioner must first determine the cause of the behavioral signs and then determine an appropriate course of treatment, bearing in mind the constraints of the aging process. A diagnosis of cognitive dysfunction syndrome is made once other medical and behavioral causes are ruled out.
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Affiliation(s)
- Gary Landsberg
- Doncaster Animal Clinic, 99 Henderson Avenue, Thornhill, Ontario L3T2K9, Canada.
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Landsberg G. Therapeutic agents for the treatment of cognitive dysfunction syndrome in senior dogs. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:471-9. [PMID: 15795056 DOI: 10.1016/j.pnpbp.2004.12.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 01/10/2023]
Abstract
With increasing age, dogs develop a form of neurodegenerative disease which has many similarities to age related cognitive impairment and Alzheimer's disease in humans. A decline in learning and memory can be demonstrated in dogs beginning as young as 7 years of age using a variety of neuropsychological tests. However, clinical cases of cognitive dysfunction syndrome are seldom identified until the age of 11 years or older. This is likely due to the fact that the owners are relying on clinical observations such as house-soiling, sleep-wake cycles and disorientation, rather than tests of learning and memory. On the other hand, dogs that are trained to more exacting tasks such as guide dogs for the visually impaired, or bomb detection and agility trained dogs might be noticed to have a decline in performance at a much earlier age. Through the use of standardized neuropsychological testing protocols, a number of drugs, natural products and supplement formulations have been developed for use in dogs with cognitive dysfunction and, in some cases clinical trials have validated their efficacy. Furthermore, the testing of products currently licensed and in the pipeline for the treatment of cognitive decline and Alzheimer's in humans, may provide additional therapeutic agents for the treatment of senior dogs, as well as provide insight as to the potential for the efficacy of these compounds in humans. This review will examine those products that are now marketed along with some that might be considered for use in senior dogs with cognitive dysfunction as well as the research that has been used to validate the efficacy (or lack thereof) of these compounds.
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Affiliation(s)
- Gary Landsberg
- Doncaster Animal Clinic, 99 Henderson Avenue, Thornhill, Ontario, Canada L3T 2K9.
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Tapp PD, Chu Y, Araujo JA, Chiou JY, Head E, Milgram NW, Su MY. Effects of scopolamine challenge on regional cerebral blood volume. A pharmacological model to validate the use of contrast enhanced magnetic resonance imaging to assess cerebral blood volume in a canine model of aging. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:399-406. [PMID: 15795048 DOI: 10.1016/j.pnpbp.2004.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 11/17/2022]
Abstract
Cognitive impairment resulting from disruption of cholinergic function may occur through modulation of cerebrovascular volume (CBV). In the present study, dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) was used to examine cerebrovascular volume in young and old dogs during baseline and after administration of a cholinergic antagonist (scopolamine). In the first study, 24 animals (2-15 years of age) were given a baseline scan followed by a second scan after scopolamine administration (30 microg/kg). Gray matter rCBV was significantly higher than white matter rCBV during baseline and scopolamine administration. In the second study a subset of 7 dogs (4 young and 3 old) received scopolamine before anesthesia was induced for a second DSC-MRI scan. Consistent with the first study, gray matter rCBV was significantly higher than white matter rCBV. Scopolamine administered before anesthesia however, resulted in higher rCBV values compared to baseline in cerebral gray matter. Additionally, rCBVs were higher in young dogs at baseline in gray and white matter and marginally higher in gray matter when scopolamine was administered before anesthesia. These results indicate that in the dog, rCBV varies with brain compartment, decreases with age, and that DSC-MRI provides a measure of cerebrovascular function which may be related to age-dependent changes in cognition, brain structure, and neuropathology.
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Affiliation(s)
- P Dwight Tapp
- John Tu and Thomas Yuen Center for Functional Onco-imaging, University of California, 164 Irvine Hall, Irvine, CA, USA
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Studzinski CM, Araujo JA, Milgram NW. The canine model of human cognitive aging and dementia: pharmacological validity of the model for assessment of human cognitive-enhancing drugs. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:489-98. [PMID: 15795058 DOI: 10.1016/j.pnpbp.2004.12.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 01/24/2023]
Abstract
For the past 15 years we have investigated the aged beagle dog as a model for human aging and dementia. We have shown that dogs develop cognitive deficits and neuropathology seen in human aging and dementia. These similarities increase the likelihood that the model will be able to accurately predict the efficacy of Alzheimer's disease (AD) treatments as well as detect therapeutics with limited or no efficacy. Better predictive validity of cognitive-enhancing therapeutics (CETs) could lead to enormous cost savings by reducing the number of failed human clinical trials and also may reduce the likelihood of negative outcomes such as those recently observed in the AN-1792 clinical trials. The current review assesses the pharmacological validity of the canine model of human aging and dementia. We tested the efficacy of (1) CP-118,954 and phenserine, two acetylcholinesterase inhibitors, (2) an ampakine, (3) selegiline hydrochloride, two drugs that have failed human AD trials, and (4) adrafinil, a putative CET. Our research demonstrates that dogs not only develop isomorphic changes in human cognition and brain pathology, but also accurately predict the efficacy of known AD treatments and the absence or limited efficacy of treatments that failed clinical trials. These findings collectively support the utilization of the dog model as a preclinical screen for identifying novel CETs for both age-associated memory disorder and dementia.
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Araujo JA, Studzinski CM, Milgram NW. Further evidence for the cholinergic hypothesis of aging and dementia from the canine model of aging. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:411-22. [PMID: 15795050 DOI: 10.1016/j.pnpbp.2004.12.008] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2004] [Indexed: 11/24/2022]
Abstract
Memory decline in human aging and dementia is linked to dysfunction of the cholinergic system. Aging dogs demonstrate cognitive impairments and neuropathology that models human aging and dementia. This paper reviews recent evidence suggesting cholinergic involvement in canine cognitive aging based on studies with the anti-cholinergic drug, scopolamine, and a novel acetylcholinesterase inhibitor, phenserine. In particular, we examine: (1) the cognitive specificity of scopolamine's impairment in dogs, (2) the effect of age on scopolamine impairment and (3) the effect of phenserine on cognitive performance in dogs. Our findings indicate that working memory performance is disrupted by scopolamine at doses that do not disrupt non-cognitive behavior or long-term, semantic-like, memory, as indicated by performance of previously learned discriminations. This pattern of deficits is also seen in human and canine aging. We demonstrate that aged dogs are more sensitive to the impairing effects of scopolamine than young dogs, suggesting a decrease in cholinergic tone with increasing age. Dogs receiving phenserine demonstrate improved learning and memory compared to placebo controls. Our findings suggest that cholinergic decline could result in memory impairment, but that the memory impairment may be secondary to deficits in attention and/or encoding of new information. Together, these results suggest that the canine cholinergic system declines with age and that the aged dog is a unique model for screening therapeutics and for examining the relationship between amyloid pathology and cholinergic dysfunction in age-dependent cognitive decline.
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Affiliation(s)
- Joseph A Araujo
- Department of Pharmacology, University of Toronto, Ontario, Canada
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