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Tabanez M, Santos IR, Ikebara JM, Camargo MLM, Dos Santos BA, Freire BM, Batista BL, Takada SH, Squitti R, Kihara AH, Cerchiaro G. The Impact of Hydroxytyrosol on the Metallomic-Profile in an Animal Model of Alzheimer's Disease. Int J Mol Sci 2023; 24:14950. [PMID: 37834398 PMCID: PMC10573659 DOI: 10.3390/ijms241914950] [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] [Received: 08/21/2023] [Revised: 09/26/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
It is undeniable that as people get older, they become progressively more susceptible to neurodegenerative illnesses such as Alzheimer's disease (AD). Memory loss is a prominent symptom of this condition and can be exacerbated by uneven levels of certain metals. This study used inductively coupled plasma mass spectrometry (ICP-MS) to examine the levels of metals in the blood plasma, frontal cortex, and hippocampus of Wistar rats with AD induced by streptozotocin (STZ). It also tested the effects of the antioxidant hydroxytyrosol (HT) on metal levels. The Barnes maze behavior test was used, and the STZ group showed less certainty and greater distance when exploring the Barnes maze than the control group. The results also indicated that the control group and the STZ + HT group exhibited enhanced learning curves during the Barnes maze training as compared to the STZ group. The ICP-MS analysis showed that the STZ group had lower levels of cobalt in their blood plasma than the control group, while the calcium levels in the frontal cortex of the STZ + HT group were higher than in the control group. The most important finding was that copper levels in the frontal cortex from STZ-treated animals were higher than in the control group, and that the STZ + HT group returned to equivalent levels to the control group. The antioxidant HT can restore copper levels to their basal physiological state. This finding may help explain HT's potential beneficial effect in AD-patients.
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Affiliation(s)
- Miguel Tabanez
- Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil; (M.T.); (I.R.S.); (M.L.M.C.); (B.M.F.); (B.L.B.)
- Metal Biochemistry and Oxidative Stress Laboratory, Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil
| | - Ilma R. Santos
- Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil; (M.T.); (I.R.S.); (M.L.M.C.); (B.M.F.); (B.L.B.)
- Metal Biochemistry and Oxidative Stress Laboratory, Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil
| | - Juliane M. Ikebara
- Center for Mathematics, Computing and Cognition, Federal University of ABC, São Bernardo do Campo 09606-045, SP, Brazil; (J.M.I.); (B.A.D.S.); (S.H.T.); (A.H.K.)
| | - Mariana L. M. Camargo
- Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil; (M.T.); (I.R.S.); (M.L.M.C.); (B.M.F.); (B.L.B.)
- Metal Biochemistry and Oxidative Stress Laboratory, Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil
| | - Bianca A. Dos Santos
- Center for Mathematics, Computing and Cognition, Federal University of ABC, São Bernardo do Campo 09606-045, SP, Brazil; (J.M.I.); (B.A.D.S.); (S.H.T.); (A.H.K.)
| | - Bruna M. Freire
- Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil; (M.T.); (I.R.S.); (M.L.M.C.); (B.M.F.); (B.L.B.)
| | - Bruno L. Batista
- Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil; (M.T.); (I.R.S.); (M.L.M.C.); (B.M.F.); (B.L.B.)
| | - Silvia H. Takada
- Center for Mathematics, Computing and Cognition, Federal University of ABC, São Bernardo do Campo 09606-045, SP, Brazil; (J.M.I.); (B.A.D.S.); (S.H.T.); (A.H.K.)
| | - Rosanna Squitti
- Department of Laboratory Science, Ospedale Isola Tiberina—Gemelli Isola, 00186 Rome, Italy;
| | - Alexandre H. Kihara
- Center for Mathematics, Computing and Cognition, Federal University of ABC, São Bernardo do Campo 09606-045, SP, Brazil; (J.M.I.); (B.A.D.S.); (S.H.T.); (A.H.K.)
| | - Giselle Cerchiaro
- Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil; (M.T.); (I.R.S.); (M.L.M.C.); (B.M.F.); (B.L.B.)
- Metal Biochemistry and Oxidative Stress Laboratory, Center for Natural Sciences and Humanities, Federal University of ABC, Santo André 09210-580, SP, Brazil
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Zhang Y, Ebelt ST, Shi L, Scovronick NC, D'Souza RR, Steenland K, Chang HH. Short-term associations between warm-season ambient temperature and emergency department visits for Alzheimer's disease and related dementia in five US states. ENVIRONMENTAL RESEARCH 2023; 220:115176. [PMID: 36584844 PMCID: PMC9898200 DOI: 10.1016/j.envres.2022.115176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 11/30/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Ambient temperatures are projected to increase in the future due to climate change. Alzheimer's disease (AD) and Alzheimer's disease-related dementia (ADRD) affect millions of individuals and represent substantial health burdens in the US. High temperature may be a risk factor for AD/ADRD outcomes with several recent studies reporting associations between temperature and AD mortality. However, the link between heat and AD morbidity is poorly understood. METHODS We examined short-term associations between warm-season daily ambient temperature and AD/ADRD emergency department (ED) visits for individuals aged 45 years or above during the warm season (May to October) for up to 14 years (2005-2018) in five US states: California, Missouri, North Carolina, New Jersey, and New York. Daily ZIP code-level maximum, average and minimum temperature exposures were derived from 1 km gridded Daymet products. Associations are assessed using a time-stratified case-crossover design using conditional logistic regression. RESULTS We found consistent positive short-term effects of ambient temperature among 3.4 million AD/ADRD ED visits across five states. An increase of the 3-day cumulative temperature exposure of daily average temperature from the 50th to the 95th percentile was associated with a pooled odds ratio of 1.042 (95% CI: 1.034, 1.051) for AD/ADRD ED visits. We observed evidence of the association being stronger for patients 65-74 years of age and for ED visits that led to hospital admissions. Temperature associations were also stronger among AD/ADRD ED visits compared to ED visits for other reasons, particularly among patients aged 65-74 years. CONCLUSION People with AD/ADRD may represent a vulnerable population affected by short-term exposure to high temperature. Our results support the development of targeted strategies to reduce heat-related AD/ADRD morbidity in the context of global warming.
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Affiliation(s)
- Yuzi Zhang
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
| | - Stefanie T Ebelt
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Liuhua Shi
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Noah C Scovronick
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Rohan R D'Souza
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Kyle Steenland
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Howard H Chang
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
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Vicente MC, Humphrey CM, Gargaglioni LH, Ostrowski TD. Decreased excitability of locus coeruleus neurons during hypercapnia is exaggerated in the streptozotocin-model of Alzheimer's disease. Exp Neurol 2020; 328:113250. [PMID: 32088169 DOI: 10.1016/j.expneurol.2020.113250] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/04/2020] [Accepted: 02/17/2020] [Indexed: 10/25/2022]
Abstract
The locus coeruleus (LC) is a pontine nucleus important for respiratory control and central chemoreception. It is affected in Alzheimer's disease (AD) and alteration of LC cell function may account for respiratory problems observed in AD patients. In the current study, we tested the electrophysiological properties and CO2/pH sensitivity of LC neurons in a model for AD. Sporadic AD was induced in rats by intracerebroventricular injection of 2 mg/kg streptozotocin (STZ), which induces behavioral and molecular impairments found in AD. LC neurons were recorded using the patch clamp technique and tested for responses to CO2 (10% CO2, pH = 7.0). The majority (~60%) of noradrenergic LC neurons in adult rats were inhibited by CO2 exposure as indicated by a significant decrease in action potential (AP) discharge to step depolarizations. The STZ-AD rat model had a greater sensitivity to CO2 than controls. The increased CO2-sensitivity was demonstrated by a significantly stronger inhibition of activity during hypercapnia that was in part due to hyperpolarization of the resting membrane potential. Reduction of AP discharge in both groups was generally accompanied by lower LC network activity, depolarized AP threshold, increased AP repolarization, and increased current through a subpopulation of voltage-gated K+ channels (KV). The latter was indicated by enhanced transient KV currents particularly in the STZ-AD group. Interestingly, steady-state KV currents were reduced under hypercapnia, a change that would favor enhanced AP discharge. However, the collective response of most LC neurons in adult rats, and particularly those in the STZ-AD group, was inhibited by CO2.
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Affiliation(s)
- Mariane C Vicente
- Department of Physiology, Kirksville College of Osteopathic Medicine, A.T. Still University of Health Sciences, Kirksville, MO, USA; Department of Animal Morphology and Physiology, Sao Paulo State University-UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Chuma M Humphrey
- Department of Biology, Truman State University, Kirksville, MO, USA
| | - Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, Sao Paulo State University-UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Tim D Ostrowski
- Department of Physiology, Kirksville College of Osteopathic Medicine, A.T. Still University of Health Sciences, Kirksville, MO, USA.
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Barilar JO, Knezovic A, Perhoc AB, Homolak J, Riederer P, Salkovic-Petrisic M. Shared cerebral metabolic pathology in non-transgenic animal models of Alzheimer's and Parkinson's disease. J Neural Transm (Vienna) 2020; 127:231-250. [PMID: 32030485 PMCID: PMC7035309 DOI: 10.1007/s00702-020-02152-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 01/24/2020] [Indexed: 12/25/2022]
Abstract
Parkinson's disease (PD) and Alzheimer's disease (AD) are the most common chronic neurodegenerative disorders, characterized by motoric dysfunction or cognitive decline in the early stage, respectively, but often by both symptoms in the advanced stage. Among underlying molecular pathologies that PD and AD patients have in common, more attention is recently paid to the central metabolic dysfunction presented as insulin resistant brain state (IRBS) and altered cerebral glucose metabolism, both also explored in animal models of these diseases. This review aims to compare IRBS and alterations in cerebral glucose metabolism in representative non-transgenic animal PD and AD models. The comparison is based on the selectivity of the neurotoxins which cause experimental PD and AD, towards the cellular membrane and intracellular molecular targets as well as towards the selective neurons/non-neuronal cells, and the particular brain regions. Mitochondrial damage and co-expression of insulin receptors, glucose transporter-2 and dopamine transporter on the membrane of particular neurons as well as astrocytes seem to be the key points which are further discussed in a context of alterations in insulin signalling in the brain and its interaction with dopaminergic transmission, particularly regarding the time frame of the experimental AD/PD pathology appearance and the correlation with cognitive and motor symptoms. Such a perspective provides evidence on IRBS being a common underlying metabolic pathology and a contributor to neurodegenerative processes in representative non-transgenic animal PD and AD models, instead of being a direct cause of a particular neurodegenerative disorder.
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Affiliation(s)
- Jelena Osmanovic Barilar
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Ana Knezovic
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Ana Babic Perhoc
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Jan Homolak
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia
| | - Peter Riederer
- Center of Mental Health, Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital, Würzburg, Füchsleinstrasse 15, 97080, Würzburg, Germany
- Department and Research Unit of Psychiatry, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Melita Salkovic-Petrisic
- Department of Pharmacology, University of Zagreb School of Medicine, Salata 11, 10 000, Zagreb, Croatia.
- Institute of Fundamental Clinical and Translational Neuroscience, Research Centre of Excellence, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 12, 10 000, Zagreb, Croatia.
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Moreira-Silva D, Vizin RCL, Martins TMS, Ferreira TL, Almeida MC, Carrettiero DC. Intracerebral Injection of Streptozotocin to Model Alzheimer Disease in Rats. Bio Protoc 2019; 9:e3397. [PMID: 33654898 DOI: 10.21769/bioprotoc.3397] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/10/2019] [Accepted: 09/12/2019] [Indexed: 01/18/2023] Open
Abstract
Animal models have promoted meaningful contribution to science including Alzheimer's disease (AD) research. Several animal models for AD have been used, most of them related to genetic mutations observed in familial AD. However, sporadic form of AD, also named late-onset is the most frequent form of the disease, which is multifactorial, being influenced by genetic, environmental and lifestyle factors. Here, we describe a protocol of an AD-like pathology of the sporadic form using Wistar rats by a single bilateral intracerebroventricular (icv) injection of streptozotocin (STZ, 2 mg/kg). Icv injection of STZ induces brain resistance to insulin and other pathological alterations related to those observed in AD, such as cognitive impairment and accumulation of phosphorylated tau protein and β-amyloid in the brain. Thus, icv injection of STZ is a useful tool to investigate the pathological mechanisms and the metabolic alterations involved in AD and to propose new therapeutic approaches and neuroprotective drugs.
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Affiliation(s)
- Daniel Moreira-Silva
- Graduate Program in Neuroscience and Cognition, Federal University of ABC, São Bernardo do Campo, Brazil
| | - Robson C L Vizin
- Graduate Program in Neuroscience and Cognition, Federal University of ABC, São Bernardo do Campo, Brazil
| | - Talita M S Martins
- Undergraduate Program in Neuroscience, Federal University of ABC, São Bernardo do Campo, Brazil
| | - Tatiana L Ferreira
- Center for Mathematics, Computing and Cognition, Federal University of ABC, São Bernardo do Campo, Brazil
| | - Maria C Almeida
- Center for Natural and Human Sciences, Federal University of ABC, São Bernardo do Campo, Brazil
| | - Daniel C Carrettiero
- Center for Natural and Human Sciences, Federal University of ABC, São Bernardo do Campo, Brazil
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Perpetuini D, Cardone D, Chiarelli AM, Filippini C, Croce P, Zappasodi F, Rotunno L, Anzoletti N, Zito M, Merla A. Autonomic impairment in Alzheimer's disease is revealed by complexity analysis of functional thermal imaging signals during cognitive tasks. Physiol Meas 2019; 40:034002. [PMID: 30736015 DOI: 10.1088/1361-6579/ab057d] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Alzheimer's disease (AD) is characterized by progressive memory failures and visuospatial impairment. Moreover, AD can be accompanied by autonomic system alterations, which, among other impacts, affect thermoregulatory activity. We here investigate differences in autonomic activity between AD patients and healthy controls (HC), employing a complexity analysis of functional infrared imaging (fIRI) data acquired at rest and during the execution of clinical cognitive and mnemonic tests. APPROACH fIRI allows for contactless monitoring of autonomic activity and its thermoregulatory expression without interfering with the psychophysiological state of the subject, preserving free interaction with the doctor. The signal complexity analysis, based on the sample entropy, was compared to a standard frequency-based analysis of autonomic-related signals. MAIN RESULTS AD patients exhibited lower complexity of fIRI signals during the tests, which could be indicative of a stronger sympathetic activity with respect to HC. No significant effects were found at rest. No differences were found on employing frequency-based analysis. SIGNIFICANCE This study confirms that AD patients may exhibit peculiar autonomic responses associated with the execution of cognitive tasks that can be measured through fIRI. Moreover, these responses could be highlighted by a nonlinear metric of signal predictability such as the sample entropy establishing autonomic impairment of AD patients.
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Affiliation(s)
- David Perpetuini
- Infrared Imaging Lab, Centro ITAB-Institute for Advanced Biomedical Technologies, University G. d'Annunzio, Chieti, 66100, Italy. Department of Neurosciences, Imaging and Clinical Sciences, University G. d'Annunzio, Chieti-Pescara, 66100, Italy. Author to whom any correspondence should be addressed
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Moreira-Silva D, Carrettiero DC, Oliveira ASA, Rodrigues S, Dos Santos-Lopes J, Canas PM, Cunha RA, Almeida MC, Ferreira TL. Anandamide Effects in a Streptozotocin-Induced Alzheimer's Disease-Like Sporadic Dementia in Rats. Front Neurosci 2018; 12:653. [PMID: 30333717 PMCID: PMC6176656 DOI: 10.3389/fnins.2018.00653] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 08/30/2018] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by multiple cognitive deficits including memory and sensorimotor gating impairments as a result of neuronal and synaptic loss. The endocannabinoid system plays an important role in these deficits but little is known about its influence on the molecular mechanism regarding phosphorylated tau (p-tau) protein accumulation - one of the hallmarks of AD -, and on the density of synaptic proteins. Thus, the aim of this study was to investigate the preventive effects of anandamide (N-arachidonoylethanolamine, AEA) on multiple cognitive deficits and on the levels of synaptic proteins (syntaxin 1, synaptophysin and synaptosomal-associated protein, SNAP-25), cannabinoid receptor type 1 (CB1) and molecules related to p-tau degradation machinery (heat shock protein 70, HSP70), and Bcl2-associated athanogene (BAG2) in an AD-like sporadic dementia model in rats using intracerebroventricular (icv) injection of streptozotocin (STZ). Our hypothesis is that AEA could interact with HSP70, modulating the level of p-tau and synaptic proteins, preventing STZ-induced cognitive impairments. Thirty days after receiving bilateral icv injections of AEA or STZ or both, the cognitive performance of adult male Wistar rats was evaluated in the object recognition test, by the escape latency in the elevated plus maze (EPM), by the tone and context fear conditioning as well as in prepulse inhibition tests. Subsequently, the animals were euthanized and their brains were removed for histological analysis or for protein quantification by Western Blotting. The behavioral results showed that STZ impaired recognition, plus maze and tone fear memories but did not affect contextual fear memory and prepulse inhibition. Moreover, AEA prevented recognition and non-associative emotional memory impairments induced by STZ, but did not influence tone fear conditioning. STZ increased the brain ventricular area and this enlargement was prevented by AEA. Additionally, STZ reduced the levels of p-tau (Ser199/202) and increased p-tau (Ser396), although AEA did not affect these alterations. HSP70 was found diminished only by STZ, while BAG2 levels were decreased by STZ and AEA. Synaptophysin, syntaxin and CB1 receptor levels were reduced by STZ, but only syntaxin was recovered by AEA. Altogether, albeit AEA failed to modify some AD-like neurochemical alterations, it partially prevented STZ-induced cognitive impairments, changes in synaptic markers and ventricle enlargement. This study showed, for the first time, that the administration of an endocannabinoid can prevent AD-like effects induced by STZ, boosting further investigations about the modulation of endocannabinoid levels as a therapeutic approach for AD.
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Affiliation(s)
- Daniel Moreira-Silva
- Center for Mathematics, Computing and Cognition, Universidade Federal do ABC, São Bernardo do Campo, Brazil
| | - Daniel C Carrettiero
- Center for Natural and Human Sciences, Universidade Federal do ABC, São Bernardo do Campo, Brazil
| | - Adriele S A Oliveira
- Center for Natural and Human Sciences, Universidade Federal do ABC, São Bernardo do Campo, Brazil
| | - Samanta Rodrigues
- Center for Mathematics, Computing and Cognition, Universidade Federal do ABC, São Bernardo do Campo, Brazil
| | - Joyce Dos Santos-Lopes
- Center for Mathematics, Computing and Cognition, Universidade Federal do ABC, São Bernardo do Campo, Brazil
| | - Paula M Canas
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Rodrigo A Cunha
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Maria C Almeida
- Center for Natural and Human Sciences, Universidade Federal do ABC, São Bernardo do Campo, Brazil
| | - Tatiana L Ferreira
- Center for Mathematics, Computing and Cognition, Universidade Federal do ABC, São Bernardo do Campo, Brazil
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Vicente MC, Almeida MC, Bícego KC, Carrettiero DC, Gargaglioni LH. Hypercapnic and Hypoxic Respiratory Response During Wakefulness and Sleep in a Streptozotocin Model of Alzheimer's Disease in Rats. J Alzheimers Dis 2018; 65:1159-1174. [PMID: 30124447 DOI: 10.3233/jad-180397] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Besides the typical cognitive decline, patients with Alzheimer's disease (AD) develop disorders of the respiratory system, such as sleep apnea, shortness of breath, and arrhythmias. These symptoms are aggravated with the progression of the disease. However, the cause and nature of these disturbances are not well understood. Here, we treated animals with intracerebroventricular streptozotocin (STZ, 2 mg/kg), a drug that has been described to cause Alzheimer-like behavioral and histopathological impairments. We measured ventilation (V̇E), electroencephalography, and electromyography during normocapnia, hypercapnia, and hypoxia in Wistar rats. In addition, we performed western blot analyses for phosphorylated tau, total tau, and amyloid-β (Aβ) peptide in the locus coeruleus (LC), retrotrapezoid nucleus, medullary raphe, pre-Bötzinger/Bötzinger complex, and hippocampus, and evaluated memory and learning acquisition using the Barnes maze. STZ treatment promoted memory and learning deficits and increased the percentage of total wakefulness during normocapnia and hypercapnia due to a reduction in the length of episodes of wakefulness. CO2-drive to breathe during wakefulness was increased by 26% in STZ-treated rats due to an enhanced tidal volume, but no changes in V̇E were observed in room air or hypoxic conditions. The STZ group also showed a 70% increase of Aβ in the LC and no change in tau protein phosphorylation. In addition, no alteration in body temperature was observed. Our findings suggest that AD animals present an increased sensitivity to CO2 during wakefulness, enhanced Aβ in the LC, and sleep disruption.
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Affiliation(s)
- Mariane C Vicente
- Department of Animal Morphology and Physiology, Sao Paulo State University-UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Maria C Almeida
- Center for Natural and Human Sciences; Universidade Federal do ABC (UFABC); São Bernardo do Campo, SP, Brazil
| | - Kênia C Bícego
- Department of Animal Morphology and Physiology, Sao Paulo State University-UNESP/FCAV at Jaboticabal, SP, Brazil
| | - Daniel C Carrettiero
- Center for Natural and Human Sciences; Universidade Federal do ABC (UFABC); São Bernardo do Campo, SP, Brazil
| | - Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, Sao Paulo State University-UNESP/FCAV at Jaboticabal, SP, Brazil
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