1
|
Deery HA, Di Paolo R, Moran C, Egan GF, Jamadar SD. Lower brain glucose metabolism in normal ageing is predominantly frontal and temporal: A systematic review and pooled effect size and activation likelihood estimates meta-analyses. Hum Brain Mapp 2022; 44:1251-1277. [PMID: 36269148 PMCID: PMC9875940 DOI: 10.1002/hbm.26119] [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: 08/02/2022] [Revised: 09/29/2022] [Accepted: 10/05/2022] [Indexed: 01/31/2023] Open
Abstract
This review provides a qualitative and quantitative analysis of cerebral glucose metabolism in ageing. We undertook a systematic literature review followed by pooled effect size and activation likelihood estimates (ALE) meta-analyses. Studies were retrieved from PubMed following the PRISMA guidelines. After reviewing 635 records, 21 studies with 22 independent samples (n = 911 participants) were included in the pooled effect size analyses. Eight studies with eleven separate samples (n = 713 participants) were included in the ALE analyses. Pooled effect sizes showed significantly lower cerebral metabolic rates of glucose for older versus younger adults for the whole brain, as well as for the frontal, temporal, parietal, and occipital lobes. Among the sub-cortical structures, the caudate showed a lower metabolic rate among older adults. In sub-group analyses controlling for changes in brain volume or partial volume effects, the lower glucose metabolism among older adults in the frontal lobe remained significant, whereas confidence intervals crossed zero for the other lobes and structures. The ALE identified nine clusters of lower glucose metabolism among older adults, ranging from 200 to 2640 mm3 . The two largest clusters were in the left and right inferior frontal and superior temporal gyri and the insula. Clusters were also found in the inferior temporal junction, the anterior cingulate and caudate. Taken together, the results are consistent with research showing less efficient glucose metabolism in the ageing brain. The findings are discussed in the context of theories of cognitive ageing and are compared to those found in neurodegenerative disease.
Collapse
Affiliation(s)
- Hamish A. Deery
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneAustralia,Monash Biomedical ImagingMonash UniversityMelbourneAustralia
| | - Robert Di Paolo
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneAustralia,Monash Biomedical ImagingMonash UniversityMelbourneAustralia
| | - Chris Moran
- Peninsula Clinical School, Central Clinical SchoolMonash UniversityFrankstonVictoriaAustralia,Department of Geriatric MedicinePeninsula HealthFrankstonVictoriaAustralia
| | - Gary F. Egan
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneAustralia,Monash Biomedical ImagingMonash UniversityMelbourneAustralia,Australian Research Council Centre of Excellence for Integrative Brain FunctionMelbourneAustralia
| | - Sharna D. Jamadar
- Turner Institute for Brain and Mental HealthMonash UniversityMelbourneAustralia,Monash Biomedical ImagingMonash UniversityMelbourneAustralia,Australian Research Council Centre of Excellence for Integrative Brain FunctionMelbourneAustralia
| |
Collapse
|
2
|
Binnie LR, Pauls MMH, Benjamin P, Dhillon MPK, Betteridge S, Clarke B, Ghatala R, Hainsworth FAH, Howe FA, Khan U, Kruuse C, Madigan JB, Moynihan B, Patel B, Pereira AC, Rostrup E, Shtaya ABY, Spilling CA, Trippier S, Williams R, Isaacs JD, Barrick TR, Hainsworth AH. Test-retest reliability of arterial spin labelling for cerebral blood flow in older adults with small vessel disease. Transl Stroke Res 2022; 13:583-594. [PMID: 35080734 PMCID: PMC9232403 DOI: 10.1007/s12975-021-00983-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/15/2021] [Accepted: 12/22/2021] [Indexed: 12/03/2022]
Abstract
Cerebral small vessel disease (SVD) is common in older people and is associated with lacunar stroke, white matter hyperintensities (WMH) and vascular cognitive impairment. Cerebral blood flow (CBF) is reduced in SVD, particularly within white matter.Here we quantified test-retest reliability in CBF measurements using pseudo-continuous arterial spin labelling (pCASL) in older adults with clinical and radiological evidence of SVD (N=54, mean (SD): 66.9 (8.7) years, 15 females/39 males). We generated whole-brain CBF maps on two visits at least 7 days apart (mean (SD): 20 (19), range 7-117 days).Test-retest reliability for CBF was high in all tissue types, with intra-class correlation coefficient [95%CI]: 0.758 [0.616, 0.852] for whole brain, 0.842 [0.743, 0.905] for total grey matter, 0.771 [0.636, 0.861] for deep grey matter (caudate-putamen and thalamus), 0.872 [0.790, 0.923] for normal-appearing white matter (NAWM) and 0.780 [0.650, 0.866] for WMH (all p<0.001). ANCOVA models indicated significant decline in CBF in total grey matter, deep grey matter and NAWM with increasing age and diastolic blood pressure (all p<0.001). CBF was lower in males relative to females (p=0.013 for total grey matter, p=0.004 for NAWM).We conclude that pCASL has high test-retest reliability as a quantitative measure of CBF in older adults with SVD. These findings support the use of pCASL in routine clinical imaging and as a clinical trial endpoint.All data come from the PASTIS trial, prospectively registered at: https://eudract.ema.europa.eu (2015-001235-20, registered 13/05/2015), http://www.clinicaltrials.gov (NCT02450253, registered 21/05/2015).
Collapse
Affiliation(s)
- Lauren R Binnie
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Mathilde M H Pauls
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Philip Benjamin
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
- Department of Neuroradiology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Mohani-Preet K Dhillon
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Shai Betteridge
- Department of Neuropsychology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Brian Clarke
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Rita Ghatala
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Fearghal A H Hainsworth
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Franklyn A Howe
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Usman Khan
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Christina Kruuse
- Department of Neurology and Neurovascular Research Unit, Herlev Gentofte Hospital, Herlev, Denmark
| | - Jeremy B Madigan
- Department of Neuroradiology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Barry Moynihan
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK
- Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Bhavini Patel
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Anthony C Pereira
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Egill Rostrup
- Mental Health Centre, University of Copenhagen, Glostrup, Denmark
| | - Anan B Y Shtaya
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Catherine A Spilling
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Sarah Trippier
- South London Stroke Research Network, St George's Hospital, London, UK
| | - Rebecca Williams
- South London Stroke Research Network, St George's Hospital, London, UK
| | - Jeremy D Isaacs
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK
| | - Thomas R Barrick
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Atticus H Hainsworth
- Molecular & Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK.
- Department of Neurology, St George's University Hospitals NHS Foundation Trust London, London, UK.
| |
Collapse
|
3
|
Powers WJ, An H, Diringer MN. Cerebral Blood Flow and Metabolism. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
4
|
Saunders AM, Burns DK, Gottschalk WK. Reassessment of Pioglitazone for Alzheimer's Disease. Front Neurosci 2021; 15:666958. [PMID: 34220427 PMCID: PMC8243371 DOI: 10.3389/fnins.2021.666958] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/18/2021] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease is a quintessential 'unmet medical need', accounting for ∼65% of progressive cognitive impairment among the elderly, and 700,000 deaths in the United States in 2020. In 2019, the cost of caring for Alzheimer's sufferers was $244B, not including the emotional and physical toll on caregivers. In spite of this dismal reality, no treatments are available that reduce the risk of developing AD or that offer prolonged mitiagation of its most devestating symptoms. This review summarizes key aspects of the biology and genetics of Alzheimer's disease, and we describe how pioglitazone improves many of the patholophysiological determinants of AD. We also summarize the results of pre-clinical experiments, longitudinal observational studies, and clinical trials. The results of animal testing suggest that pioglitazone can be corrective as well as protective, and that its efficacy is enhanced in a time- and dose-dependent manner, but the dose-effect relations are not monotonic or sigmoid. Longitudinal cohort studies suggests that it delays the onset of dementia in individuals with pre-existing type 2 diabetes mellitus, which small scale, unblinded pilot studies seem to confirm. However, the results of placebo-controlled, blinded clinical trials have not borne this out, and we discuss possible explanations for these discrepancies.
Collapse
Affiliation(s)
- Ann M. Saunders
- Zinfandel Pharmaceuticals, Inc., Chapel Hill, NC, United States
| | - Daniel K. Burns
- Zinfandel Pharmaceuticals, Inc., Chapel Hill, NC, United States
| | | |
Collapse
|
5
|
Biochemical deficits and cognitive decline in brain aging: Intervention by dietary supplements. J Chem Neuroanat 2019; 95:70-80. [DOI: 10.1016/j.jchemneu.2018.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/28/2018] [Accepted: 04/13/2018] [Indexed: 01/23/2023]
|
6
|
Zhu XH, Chen W. In vivo X-Nuclear MRS Imaging Methods for Quantitative Assessment of Neuroenergetic Biomarkers in Studying Brain Function and Aging. Front Aging Neurosci 2018; 10:394. [PMID: 30538629 PMCID: PMC6277487 DOI: 10.3389/fnagi.2018.00394] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/13/2018] [Indexed: 12/19/2022] Open
Abstract
Brain relies on glucose and oxygen metabolisms to generate biochemical energy in the form of adenosine triphosphate (ATP) for supporting electrophysiological activities and neural signaling under resting or working state. Aging is associated with declined mitochondrial functionality and decreased cerebral energy metabolism, and thus, is a major risk factor in developing neurodegenerative diseases including Alzheimer’s disease (AD). However, there is an unmet need in the development of novel neuroimaging tools and sensitive biomarkers for detecting abnormal energy metabolism and impaired mitochondrial function, especially in an early stage of the neurodegenerative diseases. Recent advancements in developing multimodal high-field in vivo X-nuclear (e.g., 2H, 17O and 31P) MRS imaging techniques have shown promise for quantitative and noninvasive measurement of fundamental cerebral metabolic rates of glucose and oxygen consumption, ATP production as well as nicotinamide adenine dinucleotide (NAD) redox state in preclinical animal and human brains. These metabolic neuroimaging measurements could provide new insights and quantitative bioenergetic markers associated with aging processing and neurodegeneration and can therefore be employed to monitor disease progression and/or determine effectiveness of therapeutic intervention.
Collapse
Affiliation(s)
- Xiao-Hong Zhu
- Center for Magnetic Resonance Research (CMRR), Department of Radiology, School of Medicine, University of Minnesota, Minneapolis, MN, United States
| | - Wei Chen
- Center for Magnetic Resonance Research (CMRR), Department of Radiology, School of Medicine, University of Minnesota, Minneapolis, MN, United States
| |
Collapse
|
7
|
Choi H, Kang H, Lee DS. Predicting Aging of Brain Metabolic Topography Using Variational Autoencoder. Front Aging Neurosci 2018; 10:212. [PMID: 30050430 PMCID: PMC6052253 DOI: 10.3389/fnagi.2018.00212] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/22/2018] [Indexed: 11/13/2022] Open
Abstract
Predicting future brain topography can give insight into neural correlates of aging and neurodegeneration. Due to variability in the aging process, it has been challenging to precisely estimate brain topographical change according to aging. Here, we predict age-related brain metabolic change by generating future brain 18F-Fluorodeoxyglucose PET. A cross-sectional PET dataset of cognitively normal subjects with different age was used to develop a generative model. The model generated PET images using age information and characteristic individual features. Predicted regional metabolic changes were correlated with the real changes obtained by follow-up data. This model was applied to produce a brain metabolism aging movie by generating PET at different ages. Normal population distribution of brain metabolic topography at each age was estimated as well. In addition, a generative model using APOE4 status as well as age as inputs revealed a significant effect of APOE4 status on age-related metabolic changes particularly in the calcarine, lingual cortex, hippocampus, and amygdala. It suggested APOE4 could be a factor affecting individual variability in age-related metabolic degeneration in normal elderly. This predictive model may not only be extended to understanding the cognitive aging process, but apply to the development of a preclinical biomarker for various brain disorders.
Collapse
Affiliation(s)
- Hongyoon Choi
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, South Korea
| | - Hyejin Kang
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, South Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, South Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea.,Korea Brain Research Institute, Daegu, South Korea
| | | |
Collapse
|
8
|
Cutler NR, Narang PK. Alzheimer's disease: clinical, neuropathologic, neuropsychologic, and brain metabolic findings. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/153331758600100105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Approximately four million individuals over 65 years ofage sufferfrom some form of dementia. A majority of these people sufferfrom an Alzheimer's-type dementia. Brain alterations associated with this disease process include neurofibrillary tangles and senile plaques and reductions in concentrations of chemical messengers. Alzheimer's-type dementia is typified by a slow decline in intellect andpersonality. It is usually diagnosed after other possibilities have been excluded, and can be correctly diagnosed only upon autopsy. Over 12 of these chemical messenger systems have been examined in Alzheimer's disease. Brain tissue of autopsied Alzheimer's patients has revealed reductions in chemical messenger systems such as the cholinergic, noradrenergic, dopaminergic, serotoninergic, and recently, somatostatin and corticotropin. Treatment strategies based on the deficits of these chemical systems has been unremarkable to date. The only treatment that has yielded positive results thus far has been with a drug of the cholinergic system, physostigmine. However, side effects limit its use. A new brain scanning methodology called Positron Emission Tomography has revealed brain metabolic deficits in the parietal and temporal lobes of the brain in patients with mild to moderate Alzheimer's disease. Patients with severe Alzheimer's disease have brain metabolic deficits throughout their brain. Effective study ofAlzheimer's disease must encompass clinicalandpost-mortem studies that include brain chemical evaluations in addition to PET scanning. A combined approach willyield a better understanding of what Alzheimer's-type dementia is, how it progresses, and how it might better be treated.
Collapse
Affiliation(s)
| | - Prem K. Narang
- Clinical Pharmacokinetics Research Laboratory, Pharmacy Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
9
|
Colgan N, Donoghue M, Zuchora Z, Tuohy B, van der Putten W. Investigation of GlucoCEST as novel clinical MR biomarker of glucose metabolism. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.05.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
10
|
Multifactorial Effects on Different Types of Brain Cells Contribute to Ammonia Toxicity. Neurochem Res 2016; 42:721-736. [PMID: 27286679 DOI: 10.1007/s11064-016-1966-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/20/2016] [Accepted: 05/24/2016] [Indexed: 12/12/2022]
Abstract
Effects of ammonia on astrocytes play a major role in hepatic encephalopathy, acute liver failure and other diseases caused by increased arterial ammonia concentrations (e.g., inborn errors of metabolism, drug or mushroom poisoning). There is a direct correlation between arterial ammonia concentration, brain ammonia level and disease severity. However, the pathophysiology of hyperammonemic diseases is disputed. One long recognized factor is that increased brain ammonia triggers its own detoxification by glutamine formation from glutamate. This is an astrocytic process due to the selective expression of the glutamine synthetase in astrocytes. A possible deleterious effect of the resulting increase in glutamine concentration has repeatedly been discussed and is supported by improvement of some pathologic effects by GS inhibition. However, this procedure also inhibits a large part of astrocytic energy metabolism and may prevent astrocytes from responding to pathogenic factors. A decrease of the already low glutamate concentration in astrocytes due to increased synthesis of glutamine inhibits the malate-aspartate shuttle and energy metabolism. A more recently described pathogenic factor is the resemblance between NH4+ and K+ in their effects on the Na+,K+-ATPase and the Na+,K+, 2 Cl- and water transporter NKCC1. Stimulation of the Na+,K+-ATPase driven NKCC1 in both astrocytes and endothelial cells is essential for the development of brain edema. Na+,K+-ATPase stimulation also activates production of endogenous ouabains. This leads to oxidative and nitrosative damage and sensitizes NKCC1. Administration of ouabain antagonists may accordingly have therapeutic potential in hyperammonemic diseases.
Collapse
|
11
|
Pietrini P, Azari NP, Pettigrew KD, Horwitz B, Kozachuk W, Kumar A, Salerno J, Grady CL, Haxby JV, Aronin N, Marshall P, Schapiro MB. Striatal Glucose Metabolism and Pattern of Cerebral Regional Interactions in Choreic Disorders. J Neuroimaging 2016. [DOI: 10.1111/jon199333151] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
12
|
Cerebral Blood Flow and Metabolism. Stroke 2016. [DOI: 10.1016/b978-0-323-29544-4.00003-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
13
|
Jeon WY, Choi YB, Kim HH. Disposable Non-Enzymatic Glucose Sensors Using Screen-Printed Nickel/Carbon Composites on Indium Tin Oxide Electrodes. SENSORS 2015; 15:31083-91. [PMID: 26690438 PMCID: PMC4721766 DOI: 10.3390/s151229846] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/24/2015] [Accepted: 12/08/2015] [Indexed: 11/16/2022]
Abstract
Disposable screen-printed nickel/carbon composites on indium tin oxide (ITO) electrodes (DSPNCE) were developed for the detection of glucose without enzymes. The DSPNCE were prepared by screen-printing the ITO substrate with a 50 wt% nickel/carbon composite, followed by curing at 400 °C for 30 min. The redox couple of Ni(OH)2/NiOOH was deposited on the surface of the electrodes via cyclic voltammetry (CV), scanning from 0–1.5 V for 30 cycles in 0.1 M NaOH solution. The DSPNCE were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical methods. The resulting electrical currents, measured by CV and chronoamperometry at 0.65 V vs. Ag/AgCl, showed a good linear response with glucose concentrations from 1.0–10 mM. Also, the prepared electrodes showed no interference from common physiologic interferents such as uric acid (UA) or ascorbic acid (AA). Therefore, this approach allowed the development of a simple, disposable glucose biosensor.
Collapse
Affiliation(s)
- Won-Yong Jeon
- Department of Nanobiomedical Sciences and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Anseo-Dong, Cheonan, Chungnam 330-714, Korea.
| | - Young-Bong Choi
- Department of Chemistry, College of Natural Science, Dankook University, Anseo-Dong, Cheonan, Chungnam 330-714, Korea.
| | - Hyug-Han Kim
- Department of Nanobiomedical Sciences and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Anseo-Dong, Cheonan, Chungnam 330-714, Korea.
- Department of Chemistry, College of Natural Science, Dankook University, Anseo-Dong, Cheonan, Chungnam 330-714, Korea.
| |
Collapse
|
14
|
Castellano CA, Baillargeon JP, Nugent S, Tremblay S, Fortier M, Imbeault H, Duval J, Cunnane SC. Regional Brain Glucose Hypometabolism in Young Women with Polycystic Ovary Syndrome: Possible Link to Mild Insulin Resistance. PLoS One 2015; 10:e0144116. [PMID: 26650926 PMCID: PMC4674147 DOI: 10.1371/journal.pone.0144116] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 11/15/2015] [Indexed: 01/20/2023] Open
Abstract
Objective To investigate whether cerebral metabolic rate of glucose (CMRglu) is altered in normal weight young women with polycystic ovary syndrome (PCOS) who exhibit mild insulin resistance. Materials and methods Seven women with PCOS were compared to eleven healthy female controls of similar age, education and body mass index. Regional brain glucose uptake was quantified using FDG with dynamic positron emission tomography and magnetic resonance imaging, and its potential relationship with insulin resistance assessed using the updated homeostasis model assessment (HOMA2-IR). A battery of cognitive tests was administered to evaluate working memory, attention and executive function. Results The PCOS group had 10% higher fasting glucose and 40% higher HOMA2-IR (p ≤ 0.035) compared to the Controls. The PCOS group had 9–14% lower CMRglu in specific regions of the frontal, parietal and temporal cortices (p ≤ 0.018). A significant negative relation was found between the CMRglu and HOMA2-IR mainly in the frontal, parietal and temporal cortices as well as in the hippocampus and the amygdala (p ≤ 0.05). Globally, cognitive performance was normal in both groups but scores on the PASAT test of working memory tended to be low in the PCOS group. Conclusions The PCOS group exhibited a pattern of low regional CMRglu that correlated inversely with HOMA2-IR in several brain regions and which resembled the pattern seen in aging and early Alzheimer’s disease. These results suggest that a direct association between mild insulin resistance and brain glucose hypometabolism independent of overweight or obesity can exist in young adults in their 20s. Further investigation of the influence of insulin resistance on brain glucose metabolism and cognition in younger and middle-aged adults is warranted.
Collapse
Affiliation(s)
- Christian-Alexandre Castellano
- Research Centre on Aging, Sherbrooke University Geriatrics Institute, Sherbrooke, QC, Canada
- Department of Pharmacology and Physiology, Université de Sherbrooke, Sherbrooke, QC, Canada
- * E-mail:
| | - Jean-Patrice Baillargeon
- Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
- Research Center of the Centre hospitalier universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Scott Nugent
- Research Centre on Aging, Sherbrooke University Geriatrics Institute, Sherbrooke, QC, Canada
- Department of Pharmacology and Physiology, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Sébastien Tremblay
- Sherbrooke Molecular Imaging Center, Université de Sherbrooke, Sherbrooke, QC, Canada
- Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Mélanie Fortier
- Research Centre on Aging, Sherbrooke University Geriatrics Institute, Sherbrooke, QC, Canada
| | - Hélène Imbeault
- Health and Social Sciences Center–Sherbrooke University Geriatrics Institute, Sherbrooke, QC, Canada
| | - Julie Duval
- Health and Social Sciences Center–Sherbrooke University Geriatrics Institute, Sherbrooke, QC, Canada
- Department of Neurology, Centre hospitalier universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Stephen C. Cunnane
- Research Centre on Aging, Sherbrooke University Geriatrics Institute, Sherbrooke, QC, Canada
- Department of Pharmacology and Physiology, Université de Sherbrooke, Sherbrooke, QC, Canada
- Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| |
Collapse
|
15
|
Blesa R, Mohr E, Miletich RS, Randolph C, Hildebrand K, Sampson M, Chase TN. Changes in cerebral glucose metabolism with normal aging. Eur J Neurol 2013; 4:8-14. [PMID: 24283817 DOI: 10.1111/j.1468-1331.1997.tb00294.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The pattern of changes in cerebral glucose metabolism occurring with normal aging has been unclear. Advances in imaging technology, such as improved resolution and anatomical referencing, allow for more precise regional measurement than previously possible. This study explored cerebral glucose metabolism in 17 normal controls ranging in age from 20 to 74 years. High resolution PET scanning, with MRI-based regions of interest correcting for partial volume and atrophy effects, revealed a linear association between advancing age and declining cerebral glucose metabolism. The decline averaged 8% per decade for the whole brain. Changes were most pronounced in limbic structures, and could be implicated in age-associated memory loss.
Collapse
Affiliation(s)
- R Blesa
- Hospital Clinic i Provincial, Servei de Neurologia, Universitat de Barcelona, Barcelona, SpainUniversity of Ottawa, Faculty of Medicine/Neurology, Ottawa Civic Hospital and Elisabeth Bruyere Health Center, Ottawa, Ontario, CanadaDent Neurological Institute, Millard Filmore Hospital, State University of New York at Buffalo, Buffalo, New York, USAExperimental Therapeutics Branch, NINDS, National Institutes of Health*, Bethesda, Maryland, USA
| | | | | | | | | | | | | |
Collapse
|
16
|
Cura AJ, Carruthers A. Role of monosaccharide transport proteins in carbohydrate assimilation, distribution, metabolism, and homeostasis. Compr Physiol 2013; 2:863-914. [PMID: 22943001 DOI: 10.1002/cphy.c110024] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The facilitated diffusion of glucose, galactose, fructose, urate, myoinositol, and dehydroascorbicacid in mammals is catalyzed by a family of 14 monosaccharide transport proteins called GLUTs. These transporters may be divided into three classes according to sequence similarity and function/substrate specificity. GLUT1 appears to be highly expressed in glycolytically active cells and has been coopted in vitamin C auxotrophs to maintain the redox state of the blood through transport of dehydroascorbate. Several GLUTs are definitive glucose/galactose transporters, GLUT2 and GLUT5 are physiologically important fructose transporters, GLUT9 appears to be a urate transporter while GLUT13 is a proton/myoinositol cotransporter. The physiologic substrates of some GLUTs remain to be established. The GLUTs are expressed in a tissue specific manner where affinity, specificity, and capacity for substrate transport are paramount for tissue function. Although great strides have been made in characterizing GLUT-catalyzed monosaccharide transport and mapping GLUT membrane topography and determinants of substrate specificity, a unifying model for GLUT structure and function remains elusive. The GLUTs play a major role in carbohydrate homeostasis and the redistribution of sugar-derived carbons among the various organ systems. This is accomplished through a multiplicity of GLUT-dependent glucose sensing and effector mechanisms that regulate monosaccharide ingestion, absorption,distribution, cellular transport and metabolism, and recovery/retention. Glucose transport and metabolism have coevolved in mammals to support cerebral glucose utilization.
Collapse
Affiliation(s)
- Anthony J Cura
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | | |
Collapse
|
17
|
Grady CL, McIntosh AR, Horwitz B, Rapoport SI. Age-related changes in the neural correlates of degraded and nondegraded face processing. Cogn Neuropsychol 2012; 17:165-86. [PMID: 20945178 DOI: 10.1080/026432900380553] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
In order to explore the neural correlates of age-related changes in visual perception of faces, positron emission tomographic scans were obtained on young and old adults while they were engaged in tasks of nondegraded and degraded face matching. Old adults were less accurate than were young adults across all face matching conditions, although the age difference was greatly reduced when degraded performance was adjusted for nondegraded performance. The interaction of age and degree of degradation on performance measures was not significant. Brain activity patterns during nondegraded face matching were similar in the two groups with some differences in parietal and prestriate cortices (greater activity in young adults) and in prefrontal cortex, thalamus, and hippocampus (greater activity in old adults). Increases in activity related to increasing degradation of the faces were seen mainly in prefrontal cortices in both age groups. Despite this similarity in the brain response to face degradation, there were striking differences between groups in the correlations between brain activity and degraded task performance. Different regions of extrastriate cortex were positively correlated with behavioural measures in the two groups (fusiform gyrus in the young adults and posterior occipital regions in old adults). In addition two areas where older adults showed greater activity during nondegraded face matching, thalamus and hippocampus, also showed positive correlations with behaviour during the degraded tasks in this group, but not in the young group. Thus, although the elderly are not more vulnerable to the effects of increasing face degradation, the brain systems involved in carrying out these visual discriminations in young and old adults are not the same. These results are consistent with the idea of functional plasticity in face processing over the life span.
Collapse
|
18
|
Steffener J, Brickman AM, Habeck CG, Salthouse TA, Stern Y. Cerebral blood flow and gray matter volume covariance patterns of cognition in aging. Hum Brain Mapp 2012; 34:3267-79. [PMID: 22806997 DOI: 10.1002/hbm.22142] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 04/16/2012] [Accepted: 05/14/2012] [Indexed: 11/11/2022] Open
Abstract
Advancing age results in altered cognitive and neuroimaging-derived markers of neural integrity. Whether cognitive changes are the result of variations in brain measures remains unclear and relating the two across the lifespan poses a unique set of problems. It must be determined whether statistical associations between cognitive and brain measures truly exist and are not epiphenomenal due solely to their shared relationships with age. The purpose of this study was to determine whether cerebral blood flow (CBF) and gray matter volume (GMV) measures make unique and better predictions of cognition than age alone. Multivariate analyses identified brain-wide covariance patterns from 35 healthy young and 23 healthy older adults using MRI-derived measures of CBF and GMV related to three cognitive composite scores (i.e., memory, fluid ability, and speed/attention). These brain-cognitive relationships were consistent across the age range, and not the result of epiphenomenal associations with age and each imaging modality provided its own unique information. The CBF and GMV patterns each accounted for unique aspects of cognition and accounted for nearly all the age-related variance in the cognitive composite scores. The findings suggest that measures derived from multiple imaging modalities explain larger amounts of variance in cognition providing a more complete understanding of the aging brain.
Collapse
Affiliation(s)
- Jason Steffener
- Cognitive Neuroscience Division of the Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York; Department of Neurology, Columbia University of Physicians and Surgeons, New York, New York
| | | | | | | | | |
Collapse
|
19
|
Marié R, Rioux P, Baron J. Resting brain metabolism and the central executive of working memory in Parkinson's disease. Eur J Neurol 2011. [DOI: 10.1111/j.1468-1331.1996.tb00214.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
20
|
|
21
|
Cunnane S, Nugent S, Roy M, Courchesne-Loyer A, Croteau E, Tremblay S, Castellano A, Pifferi F, Bocti C, Paquet N, Begdouri H, Bentourkia M, Turcotte E, Allard M, Barberger-Gateau P, Fulop T, Rapoport SI. Brain fuel metabolism, aging, and Alzheimer's disease. Nutrition 2011; 27:3-20. [PMID: 21035308 PMCID: PMC3478067 DOI: 10.1016/j.nut.2010.07.021] [Citation(s) in RCA: 390] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2010] [Revised: 07/28/2010] [Accepted: 07/28/2010] [Indexed: 12/14/2022]
Abstract
Lower brain glucose metabolism is present before the onset of clinically measurable cognitive decline in two groups of people at risk of Alzheimer's disease--carriers of apolipoprotein E4, and in those with a maternal family history of AD. Supported by emerging evidence from in vitro and animal studies, these reports suggest that brain hypometabolism may precede and therefore contribute to the neuropathologic cascade leading to cognitive decline in AD. The reason brain hypometabolism develops is unclear but may include defects in brain glucose transport, disrupted glycolysis, and/or impaired mitochondrial function. Methodologic issues presently preclude knowing with certainty whether or not aging in the absence of cognitive impairment is necessarily associated with lower brain glucose metabolism. Nevertheless, aging appears to increase the risk of deteriorating systemic control of glucose utilization, which, in turn, may increase the risk of declining brain glucose uptake, at least in some brain regions. A contributing role of deteriorating glucose availability to or metabolism by the brain in AD does not exclude the opposite effect, i.e., that neurodegenerative processes in AD further decrease brain glucose metabolism because of reduced synaptic functionality and hence reduced energy needs, thereby completing a vicious cycle. Strategies to reduce the risk of AD by breaking this cycle should aim to (1) improve insulin sensitivity by improving systemic glucose utilization, or (2) bypass deteriorating brain glucose metabolism using approaches that safely induce mild, sustainable ketonemia.
Collapse
Affiliation(s)
- Stephen Cunnane
- Research Center on Aging, Health and Social Services Center-Sherbrooke University Geriatrics Institute, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Physiology and Biophysics, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Scott Nugent
- Research Center on Aging, Health and Social Services Center-Sherbrooke University Geriatrics Institute, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Physiology and Biophysics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Maggie Roy
- Research Center on Aging, Health and Social Services Center-Sherbrooke University Geriatrics Institute, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Physiology and Biophysics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Alexandre Courchesne-Loyer
- Research Center on Aging, Health and Social Services Center-Sherbrooke University Geriatrics Institute, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Physiology and Biophysics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Etienne Croteau
- Department of Radiobiology and Nuclear Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Sébastien Tremblay
- Research Center on Aging, Health and Social Services Center-Sherbrooke University Geriatrics Institute, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Radiobiology and Nuclear Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Alex Castellano
- Research Center on Aging, Health and Social Services Center-Sherbrooke University Geriatrics Institute, Université de Sherbrooke, Sherbrooke, QC, Canada
| | | | - Christian Bocti
- Research Center on Aging, Health and Social Services Center-Sherbrooke University Geriatrics Institute, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Nancy Paquet
- Department of Radiobiology and Nuclear Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Hadi Begdouri
- Department of Radiobiology and Nuclear Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - M'hamed Bentourkia
- Department of Radiobiology and Nuclear Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Eric Turcotte
- Department of Radiobiology and Nuclear Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Michèle Allard
- UMR CNRS 5231 and Ecole Pratique des Hautes Etudes, France
| | - Pascale Barberger-Gateau
- INSERM U897, Bordeaux F-33076, France; Université Victor Segalen Bordeaux 2, Bordeaux F-33076, France
| | - Tamas Fulop
- Research Center on Aging, Health and Social Services Center-Sherbrooke University Geriatrics Institute, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Stanley I Rapoport
- Brain Physiology and Metabolism Section, National Institute of Aging, Bethesda, MD, USA
| |
Collapse
|
22
|
|
23
|
Parks RW, Thiyagesh SN, Farrow TFD, Ingram L, Wilkinson K, Hunter MD, Wilkinson ID, Young C, Woodruff PWR. Performance on the Clock Drawing Task Correlates with fMRI Response to a Visuospatial Task in Alzheimer's Disease. Int J Neurosci 2010; 120:335-43. [DOI: 10.3109/00207450903320339] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
24
|
Abstract
Investigation of the interplay between the cerebral circulation and brain cellular function is fundamental to understanding both the pathophysiology and treatment of stroke. Currently, PET is the only technique that provides accurate, quantitative in vivo regional measurements of both cerebral circulation and cellular metabolism in human subjects. We review normal human cerebral blood flow and metabolism and human PET studies of ischemic stroke, carotid artery disease, vascular dementia, intracerebral hemorrhage and aneurysmal subarachnoid hemorrhage and discuss how these studies have added to our understanding of the pathophysiology of human cerebrovascular disease.
Collapse
Affiliation(s)
- William J. Powers
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Allyson R. Zazulia
- Departments of Neurology and Radiology, Washington University School of Medicine, St. Louis, MO
| |
Collapse
|
25
|
Resting cerebral blood flow, attention, and aging. Brain Res 2009; 1267:77-88. [PMID: 19272361 DOI: 10.1016/j.brainres.2009.02.053] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 01/27/2009] [Accepted: 02/25/2009] [Indexed: 11/21/2022]
Abstract
Aging is accompanied by a decline of fluid cognitive functions, e.g., a slowing of information processing, working memory, and division of attention. This is at least partly due to structural and functional changes in the aging brain. Although a decrement of resting cerebral blood flow (CBF) has been positively associated with cognitive functions in patients with brain diseases, studies with healthy participants have revealed inconsistent results. Therefore, we investigated the relation between resting cerebral blood flow and cognitive functions (tonic and phasic alertness, selective and divided attention) in two samples of healthy young and older participants. We found higher resting CBF and better cognitive performances in the young than in the older sample. In addition, resting CBF was inversely correlated with selective attention in the young and with tonic alertness in the elderly participants. This finding is discussed with regard to the neural efficiency hypothesis of human intelligence.
Collapse
|
26
|
Vlassenko AG, Rundle MM, Mintun MA. Human brain glucose metabolism may evolve during activation: findings from a modified FDG PET paradigm. Neuroimage 2006; 33:1036-41. [PMID: 17035047 DOI: 10.1016/j.neuroimage.2006.06.065] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Revised: 06/12/2006] [Accepted: 06/20/2006] [Indexed: 10/24/2022] Open
Abstract
In human brain, short-term physiological stimulation results in dramatic and proportional increase in blood flow and metabolic rate of glucose but minimal change in oxygen utilization, however, with continuing stimulation, we have observed that blood flow response diminishes and oxygen utilization increases. Given the temporal limitation of conventional methods to measure glucose metabolism in the human brain, we modified [(18)F]fluorodeoxyglucose (FDG) PET paradigm to evaluate the short-term and long-term effects of visual stimulation on human brain glucose metabolism. In the present study, seven healthy volunteers each underwent three dynamic FDG PET studies: at rest and after 1 min and 15 min of visual stimulation (using reversing black-white checkerboard) which continued for only 5 min after FDG injection. We found that increase in FDG uptake in the visual cortex was attenuated by 28% when preceded by 15 min of continuous visual stimulation (p<0.001). This decline in metabolism occurred in the absence of any behavior changes in task performance. The similarity in behavior of blood flow and glucose metabolism over time supports the hypothesis that, in activated brain, blood flow is modulated by changes in cytosolic free NADH/NAD(+) ratio related to increased glycolysis. Furthermore, the observed decline in glucose metabolism may reflect a shift from glycolytic to oxidative glucose metabolism with continued activation.
Collapse
Affiliation(s)
- Andrei G Vlassenko
- Mallinckrodt Institute of Radiology, Box 8225, Washington University School of Medicine, 510 South Kingshighway Blvd. St,. Louis, MO 63110, USA
| | | | | |
Collapse
|
27
|
Grady CL, Springer MV, Hongwanishkul D, McIntosh AR, Winocur G. Age-related Changes in Brain Activity across the Adult Lifespan. J Cogn Neurosci 2006. [DOI: 10.1162/jocn.2006.18.2.227] [Citation(s) in RCA: 335] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
A number of theories have emerged to explain the well-studied changes in memory that occur with age. Many of these theories invoke mechanisms that have the potential to affect multiple cognitive domains, in addition to memory. Such mechanisms include alterations in attentional or inhibitory function, or dysfunction of specific brain areas, such as the frontal lobes. To gain insight into these mechanisms, we used functional magnetic resonance imaging to examine brain activity during encoding and recognition tasks in young, middle-aged, and older adults to identify correlations between age and brain activity across the various tasks. The goal was to see whether these correlations were task-specific or common across tasks, and to determine whether age differences emerged in a linear fashion over the adult years. Across all memory tasks, at both encoding and recognition, linear increases of activity with age were found in areas normally decreased during task performance (e.g., medial frontal and parietal regions), whereas activity in regions with task-related activation (e.g., dorsolateral prefrontal cortex) decreased with age. These results suggest that there is a gradual, age-related reduction in the ability to suspend non-task-related or “default-mode” activity and engage areas for carrying out memory tasks. Such an alteration in the balance between default-mode and task-related activity could account for increased vulnerability to distraction from irrelevant information, and thereby affect multiple cognitive domains.
Collapse
|
28
|
Yanase D, Matsunari I, Yajima K, Chen W, Fujikawa A, Nishimura S, Matsuda H, Yamada M. Brain FDG PET study of normal aging in Japanese: effect of atrophy correction. Eur J Nucl Med Mol Imaging 2005; 32:794-805. [PMID: 15759148 DOI: 10.1007/s00259-005-1767-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Accepted: 01/03/2005] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to investigate the effects of atrophy correction on the results of 18F-fluorodeoxyglucose positron emission tomography (FDG PET) in the context of normal aging. METHODS Before the human study was performed, a Hoffman 3D brain phantom experiment was carried out in order to validate a newly developed correction method for partial volume effects (PVEs). Brain FDG PET was then performed in 139 healthy Japanese volunteers (71 men, 68 women; age 24-81 years). PET images were corrected for PVEs using grey matter volume, which was segmented from co-registered magnetic resonance images and convoluted with the spatial resolution of the PET scanner. We investigated the correlation between advancing age and relative regional FDG activity, which was normalised to the global activity before and after PVE correction using Statistical Parametric Mapping 99. RESULTS The PET image, when corrected for PVEs, provided more homogeneous tracer distribution in the whole phantom than in the original PET image. The human PET study of both sexes revealed significant negative correlations between age and relative FDG activity in the bilateral perisylvian and medial frontal areas before PVE correction. However, these negative correlations were largely resolved after PVE correction. CONCLUSION Correction for PVEs was effective in our FDG PET study. The reduction in FDG uptake with advancing age that was detected by FDG PET without PVE correction could be accounted for largely by an age-related cerebral volume loss in the bilateral perisylvian and medial frontal areas.
Collapse
Affiliation(s)
- Daisuke Yanase
- Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Ibáñez V, Pietrini P, Furey ML, Alexander GE, Millet P, Bokde ALW, Teichberg D, Schapiro MB, Horwitz B, Rapoport SI. Resting state brain glucose metabolism is not reduced in normotensive healthy men during aging, after correction for brain atrophy. Brain Res Bull 2004; 63:147-54. [PMID: 15130704 DOI: 10.1016/j.brainresbull.2004.02.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Revised: 01/26/2004] [Accepted: 02/02/2004] [Indexed: 11/16/2022]
Abstract
Studies using positron emission tomography (PET) have reported that global and regional values for cerebral blood flow and metabolic rates for glucose (CMRglc and rCMRglc) decline with age in humans. We wished to determine if such decreases could have reflected a partial volume effect (PVE) of cerebral atrophy in the elderly, rather than "intrinsic" reductions per gram brain. We used PET to compare rCMRglc, before and after correcting for the PVE, between 13 healthy older men (aged: 55-82 years) and 11 healthy young men (aged: 22-34 years). PET was performed with 18F-fluoro-2-deoxy-d-glucose while the subjects were in the "resting" state (eyes covered and ears plugged with cotton). The PET scans were normalized to a common brain volume after superimposing them on the subjects' tissue segmented magnetic resonance scans. Analysis showed that rCMRglc in the absence of a PVE correction was significantly less in the older group in insular, frontal, superior temporal cortical, and thalamic regions. Statistical significant differences in rCMRglc, however, were absent after the PVE correction. Thus, statistically significant age reductions in regional brain glucose metabolism, corrected for brain atrophy, are not detectable in healthy normotensive men scanned while in the resting state.
Collapse
Affiliation(s)
- Vicente Ibáñez
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Zazulia AR, Markham J, Powers WJ. Cerebral Blood Flow and Metabolism in Human Cerebrovascular Disease. Stroke 2004. [DOI: 10.1016/b0-44-306600-0/50047-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
31
|
Brodtmann A, Puce A, Syngeniotis A, Darby D, Donnan G. The functional magnetic resonance imaging hemodynamic response to faces remains stable until the ninth decade. Neuroimage 2003; 20:520-8. [PMID: 14527612 DOI: 10.1016/s1053-8119(03)00237-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The effects of aging on blood oxygen level dependent signal changes and the hemodynamic response (HDR) remain controversial. Using functional magnetic resonance (MR) imaging, we examined the HDR properties and activated voxel counts in striate and extrastriate cortex in 18 healthy elderly subjects in response to a simple visual paradigm. Subjects of equal number and gender were prospectively separated into groups from the seventh, eighth, and ninth decades. Activation data were compared with those of 6 healthy subjects aged 30-39 under the same conditions. We found no systematic difference in HDR amplitude, shape, or latency across these groups. However, increasing age over 60 was associated with a significant decline in activated voxel counts, relative to the young controls. The results are discussed in comparison with previously published studies and in the context of the effects of aging on MR signal change. While robust activation can be produced in the striate and extrastriate cortices until the end of the ninth decade, caution should be exercised when comparing data from subjects in different decades. As functional magnetic resonance imaging is increasingly being used to examine patients with stroke and dementia, these results emphasize the importance of careful selection and age matching of control subjects when comparing with a patient population affected by disease processes associated with aging.
Collapse
Affiliation(s)
- Amy Brodtmann
- National Stroke Research Institute, Austin & Repatriation Medical Centre, and Department of Medicien, University of Melbourne, Melbourne, Australia.
| | | | | | | | | |
Collapse
|
32
|
Meltzer CC, Becker JT, Price JC, Moses-Kolko E. Positron emission tomography imaging of the aging brain. Neuroimaging Clin N Am 2003; 13:759-67. [PMID: 15024959 DOI: 10.1016/s1052-5149(03)00108-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PET imaging provides a vital means to study the human brain in vivo in aging and early disease states. PET studies using selective markers for brain metabolism and neurotransmitter function have uncovered a wealth of information on healthy and pathologic brain aging, and its relationship to behavior and mood states. Recognition of inherent potential confounds in the use of PET in aging studies is essential to the proper interpretation of these data.
Collapse
Affiliation(s)
- Carolyn Cidis Meltzer
- Department of Radiology, University of Pittsburgh School of Medicine, CHP MT 3972, 200 Lothrop Street, Pittsburgh, PA 15213-2582, USA.
| | | | | | | |
Collapse
|
33
|
Abstract
Imaging of brain function and neurotransmission is an important bridge between basic and clinical research. Regional cerebral energy metabolism and blood flow are normally coupled to regional cerebral function. Positron tomography (PET) studies of cerebral glucose metabolism and blood flow, single photon tomography (SPECT) and MRI studies of cerebral perfusion, have been used to image cerebral development and aging in man. The sensitivity, temporal resolution, spatial resolution and lack of radiation have led to the widespread utilization of blood oxygen level dependent (BOLD) and MRI perfusion techniques. PET and SPECT methods for studying cerebral neurotransmission include studies of dopaminergic, serotonergic, cholinergic, opiate and GABAergic neurotransmission in man. Studies of cerebral neurotransmission in man have helped to delineate the mechanisms of action of antipsychotic and antidepressant drugs, the diagnosis and progression of Parkinson's disease, and to evaluate neuroprotective drugs. The strengths, limitations, and application of these modalities are reviewed. The application of these methods to cerebral development and aging are briefly discussed.
Collapse
Affiliation(s)
- Robert M Kessler
- Department of Radiology, Vanderbilt University Medical Center, 21st and Garland, VUH 920, Nashville, TN 37232-2675, USA.
| |
Collapse
|
34
|
Tapp PD, Siwak CT, Estrada J, Holowachuk D, Milgram NW. Effects of age on measures of complex working memory span in the beagle dog (Canis familiaris) using two versions of a spatial list learning paradigm. Learn Mem 2003; 10:148-60. [PMID: 12663753 PMCID: PMC196663 DOI: 10.1101/lm.56503] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2002] [Accepted: 01/16/2003] [Indexed: 11/24/2022]
Abstract
The present study used two versions of a spatial list learning (SLL) paradigm to examine the effects of increased cognitive load on visuospatial working memory processes in young and old beagle dogs. In the first experiment, young, and a select group of old dogs were first presented with one item, then two, and then three, and were rewarded for responding to the novel position. The dogs were able to learn the task at short delays, but compared with young dogs, old dogs performed worse at delays of 10 sec, and could not reach longer delays. Analysis of errors indicated that memory was best for end items in the spatial list and that within sessions, the number of errors in later trials was greater than the number of errors in earlier trials. A second version of the task, a modified SLL (mSLL) was developed to control for the use of non-mnemonic strategies on the SLL task. In this version, the first two items were presented individually. Acquisition and maximal memory performance were better in the young relative to the old dogs. Similar to the original SLL design, memory for early list items was worse than memory for later list items in both young and old dogs. The within-session pattern of errors however, did not change from trial to trial on the mSLL. The present results suggest that multiple working memory processes are engaged during complex tests of visuospatial function and the neuroanatomical substrates controlling these processes are affected differentially by age in the beagle dog.
Collapse
Affiliation(s)
- P Dwight Tapp
- Department of Psychology, University of Toronto, Scarborough, Ontario M1C 1A4, Canada
| | | | | | | | | |
Collapse
|
35
|
Willis MW, Ketter TA, Kimbrell TA, George MS, Herscovitch P, Danielson AL, Benson BE, Post RM. Age, sex and laterality effects on cerebral glucose metabolism in healthy adults. Psychiatry Res 2002; 114:23-37. [PMID: 11864807 DOI: 10.1016/s0925-4927(01)00126-3] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Normal cerebral glucose metabolism (CMRglc) was assessed with positron emission tomography in 66 healthy adults (28 women, 38 men; mean age 39, range 20--69 years) to determine effects of age, sex and laterality on CMRglc using statistical parametric mapping. Significant age-related decreases in global metabolism (gCMRglc) were noted in the entire sample and in both sexes, as well as widespread and bilateral decreases in cortical absolute regional metabolism (rCMRglc) and more focal anterior paralimbic normalized rCMRglc. However, significant positive correlations of age with normalized rCMRglc were observed in cerebellum, thalamus and occipital areas. Although the declines in gCMRglc and rCMRglc with age did not significantly differ between sexes, men compared with women had significantly lower gCMRglc and widespread decreased cortical and subcortical absolute rCMRglc. In the entire sample, and similarly in both sexes, left greater than right asymmetry was observed in medial frontal gyrus, posterior thalamus, lingual gyrus, cuneus and superior cingulate. The opposite laterality appeared in mesio-anterior cerebellum, and lateral frontal and temporal regions. Few regions showed significant interactions of metabolic laterality with either age or sex. These findings contribute toward a convergence in the literature, and the regression models of CMRglc vs. age serve as a normative database to which patients may be compared.
Collapse
Affiliation(s)
- Mark W Willis
- Biological Psychiatry Branch, National Institute of Mental Health, 10 Center Drive MSC-1272, Bethesda, MD 20892-1272, USA.
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Cidis Meltzer C. Brain aging research at the close of the 20th century: from bench to bedside. DIALOGUES IN CLINICAL NEUROSCIENCE 2001. [PMID: 22034395 PMCID: PMC3181658 DOI: 10.31887/dcns.2001.3.3/ccmeltzer] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Remarkable and continued growth in the field of brain aging research has been fueled by a confluence of factors. Developments in molecular biology, imaging, and genetics coupled with the imperative caused by the aging of the population has created fertile ground for improved understanding of the interaction between brain function and behavior. Aging changes in neurochemical systems may account for the spectrum of cognitive and behavioral states of successfully aged pen sons, but may also contribute to enhanced vulnerability to depressive or dementing illness. In particular, the refinement of in vivo imaging approaches to investigating the structure and function of the aging brain has provided the opportunity to strengthen our knowledge of the biological substrate of the aging brain and neuropsychiatrie disorders, and translate these into therapeutics.
Collapse
|
37
|
Bentourkia M, Bol A, Ivanoiu A, Labar D, Sibomana M, Coppens A, Michel C, Cosnard G, De Volder AG. Comparison of regional cerebral blood flow and glucose metabolism in the normal brain: effect of aging. J Neurol Sci 2000; 181:19-28. [PMID: 11099707 DOI: 10.1016/s0022-510x(00)00396-8] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The regional cerebral blood flow (rCBF) and metabolic rate for glucose (rCMRGlc) are associated with functional activity of the neural cells. The present work reports a comparison study between rCBF and rCMRGlc in a normal population as a function of age. 10 young (25.9+/-5.6 years) and 10 old (65.4+/-6.1 years) volunteers were similarly studied at rest. In each subject, rCBF and rCMRGlc were measured in sequence, during the same session. Both rCBF and rCMRGlc values were found to decrease from young (mean rCBF=43.7 ml/100 g per min; mean rCMRGlc=40.6 micromol/100 g per min) to old age (mean rCBF=37.3 ml/100 g per min; mean rCMRGlc=35.2 micromol/100 g per min), resulting in a drop over 40 years of 14.8% (0.37%/year) and 13.3% (0.34%/year), respectively. On a regional basis, the frontal and the visual cortices were observed to have, respectively, the highest and the lowest reduction in rCBF, while, for rCMRGlc, these extremes were observed in striatum and cerebellum. Despite these differences, the ratio of rCBF to rCMRGlc was found to have a similar behavior in all brain regions for young and old subjects as shown by a correlation coefficient of 88%. This comparative study indicates a decline in rCBF and rCMRGlc values and a coupling between CBF and CMRGlc as a function of age.
Collapse
Affiliation(s)
- M Bentourkia
- Positron Tomography Laboratory, University of Louvain, 2 Chemin du Cyclotron, B-1348, Louvain-la-Neuve, Belgium
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Ivançević V, Alavi A, Souder E, Mozley PD, Gur RE, Bénard F, Munz DL. Regional cerebral glucose metabolism in healthy volunteers determined by fluordeoxyglucose positron emission tomography: appearance and variance in the transaxial, coronal, and sagittal planes. Clin Nucl Med 2000; 25:596-602. [PMID: 10944013 DOI: 10.1097/00003072-200008000-00005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE In this study, the contribution of the transaxial, coronal, and sagittal planes in evaluations of regional cerebral glucose metabolism was investigated in healthy volunteers as determined by fluorine-18-labeled 2-deoxy-2-fluoro-D-glucose (FDG) and high-resolution positron emission tomography (PET). METHODS One hundred twenty-seven healthy right-handed volunteers were injected with 4.2 MBq/kg (0.11 mCi) body weight FDG and imaged in a PENN PET H 240 scanner. Images were corrected for scatter and random coincidences and reconstructed in all three planes into 6- to 8-mm-thick slices. The reconstructed images were corrected for attenuation using the Chang algorithm. The transverse, coronal, and sagittal images were read independently of each other using a qualitative scale in which 1 = equal to, 2 = mildly, 3 = moderately, and 4 = markedly less than the area with the highest glucose metabolism in the respective plane. RESULTS The areas with the highest glucose metabolisms were the posterior cingulate gyri with mean scores of 1.1 to 1.2, thalami (1.2 to 1.3), basal ganglia (1.5 to 1.9), and visual cortex (1.6). The lowest values were found in the occipital cortex (2.7 to 2.8) and the cerebellum (2.3 to 2.4). Whereas reliable analysis of the mesial temporal aspects was not feasible in the sagittal plane, the anterior poles of the temporal and frontal lobes could not be evaluated in the coronal or the inferior temporal areas in the transaxial slices. In all three planes, regional glucose metabolism was less in the lateral temporal areas on the left than on the right (P < 0.001). The consistency of readings as measured in terms of coefficients of variation was greatest in the coronal plane for the caudates and posterior cingulate gyri, in the transaxial plane for the lateral temporal regions, and in the sagittal plane for the visual cortex. Age-dependent decreases in regional glucose metabolism in the inferior and lateral frontal regions and the parietal lobes were found in all three planes. CONCLUSIONS All three projection planes must be used for a comprehensive qualitative evaluation of the regional glucose metabolism of the brain.
Collapse
Affiliation(s)
- V Ivançević
- Clinic for Nuclear Medicine, University Hospital Charité, Humboldt University, Berlin, Germany.
| | | | | | | | | | | | | |
Collapse
|
39
|
Sakamoto S, Ishii K. Low cerebral glucose extraction rates in the human medial temporal cortex and cerebellum. J Neurol Sci 2000; 172:41-8. [PMID: 10620659 DOI: 10.1016/s0022-510x(99)00286-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous studies have reported that there exist different regional sensitivities to acute hypoxia. To better understand these differences, we estimated regional differences of cerebral blood flow (CBF), cerebral glucose metabolism (CMRglc) and kinetic constants (K(1), k(2), k(3)) in the human cortex under resting conditions. CBF, CMRglc, kinetic rate constants and glucose extraction rate (GER) were measured in eight normal male subjects (mean age: 26.1+/- 4.9 years) using the 15O-water autoradiographic technique and subsequently the dynamic and the static [18F]2-fluoro-2-deoxy-D-glucose technique with positron emission tomography (PET). Of all the brain structures investigated, the medial temporal lobe showed the lowest CBF (46.0 ml/100 g/min) and lowest CMRglc (3.97 mg/100 g/min). The medial temporal GER was lowest (8.9%), followed by the cerebellar GER (9.3%). While the cerebellar blood flow (64.0 ml/100 g/min) was the highest, the cerebellar metabolic rate for glucose (5.79 mg/100 g/min) was relatively low. The cerebellum showed the highest K(1) value (0.13) and k(2) value (0.16), and the lowest k(3) value (0.05). In the medial temporal cortices and cerebellum, CMRglc and GER were lower than those in the neocortices. These results indicate that there are great perfusional/metabolic differences between the medial temporal lobe, cerebellum and other brain regions in the normal human brain under resting conditions.
Collapse
Affiliation(s)
- S Sakamoto
- Department of Radiology, Kobe University School of Medicine, 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, Japan.
| | | |
Collapse
|
40
|
Covington JW, Geisler MW, Polich J, Murphy C. Normal aging and odor intensity effects on the olfactory event-related potential. Int J Psychophysiol 1999; 32:205-14. [PMID: 10437632 DOI: 10.1016/s0167-8760(99)00012-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Olfactory event-related potentials (OERPs) were recorded in 14 young and 14 older adults, with odor strength of isoamyl acetate manipulated to assess olfactory stimulus intensity. Young participants produced significantly larger N1/P2, N2/P3 amplitudes and shorter N1, P2 and N2 latencies than older participants. Medium- and high-odor concentrations elicited significantly shorter P2 and N2 latencies than the lowest concentration for both age groups. Odor concentration appears to affect the speed of olfactory stimulus information processing regardless of age.
Collapse
Affiliation(s)
- J W Covington
- Department of Psychology, San Diego State University, CA 92120-4913, USA
| | | | | | | |
Collapse
|
41
|
Grady CL, Horwitz B, Pietrini P, Mentis MJ, Ungerleider LG, Rapoport SI, Haxby JV. Effect of task difficulty on cerebral blood flow during perceptual matching of faces. Hum Brain Mapp 1998; 4:227-39. [DOI: 10.1002/(sici)1097-0193(1996)4:4<227::aid-hbm1>3.0.co;2-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
42
|
Grady CL, McIntosh AR, Bookstein F, Horwitz B, Rapoport SI, Haxby JV. Age-related changes in regional cerebral blood flow during working memory for faces. Neuroimage 1998; 8:409-25. [PMID: 9811558 DOI: 10.1006/nimg.1998.0376] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Young and old adults underwent positron emission tomography during the performance of a working memory task for faces (delayed match-to-sample), in which the delay between the sample and choice faces was varied from 1 to 21 s. Reaction time was slower and accuracy lower in the old group, but not markedly so. Values of regional cerebral blood flow (rCBF) were analyzed for sustained activity across delay conditions, as well as for changes as delay increased. Many brain regions showed similar activity during these tasks in both young and old adults, including left anterior prefrontal cortex, which had increased rCBF with delay, and ventral extrastriate cortex, which showed decreased rCBF with delay. However, old adults had less activation overall and less modulation of rCBF across delay in right ventrolateral prefrontal cortex than did the young adults. Old adults also showed greater rCBF activation in left dorsolateral prefrontal cortex across all WM delays and increased rCBF at short delays in left occipitoparietal cortex compared to young adults. Activity in many of these regions was differentially related to performance in that it was associated with decreasing response times in the young group and increasing response times in the older individuals. Thus despite the finding that performance on these memory tasks and associated activity in a number of brain areas are relatively preserved in old adults, differences elsewhere in the brain suggest that different strategies or cognitive processes are used by the elderly to maintain memory representations over short periods of time.
Collapse
Affiliation(s)
- C L Grady
- Baycrest Centre for Geriatric Care, Rotman Research Institute, Toronto, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
43
|
Hazlett EA, Buchsbaum MS, Mohs RC, Spiegel-Cohen J, Wei TC, Azueta R, Haznedar MM, Singer MB, Shihabuddin L, Luu-Hsia C, Harvey PD. Age-related shift in brain region activity during successful memory performance. Neurobiol Aging 1998; 19:437-45. [PMID: 9880046 DOI: 10.1016/s0197-4580(98)00075-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Coregistered positron emission tomography (PET)/magnetic resonance imaging (MRI) was used to characterize brain function in 70 volunteers, aged 20-87 years, during a verbal memory task. Frontal activity showed an age-related decline that remained significant after statistical control for sulcal atrophy. Analyses of young and old subgroups matched for memory scores revealed that young good performers activated frontal regions, whereas old good performers relied on occipital regions. Although activating different cortical regions, good performers of all ages used the same cognitive strategy semantic clustering. Age-related functional change may reflect dynamic re-allocation in a network of brain areas, not merely anatomically fixed neuronal loss or diminished capacity to perform.
Collapse
Affiliation(s)
- E A Hazlett
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029-6574, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Petit-Taboué MC, Landeau B, Desson JF, Desgranges B, Baron JC. Effects of healthy aging on the regional cerebral metabolic rate of glucose assessed with statistical parametric mapping. Neuroimage 1998; 7:176-84. [PMID: 9597659 DOI: 10.1006/nimg.1997.0318] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aging process is thought to result in changes in synaptic activity reflecting both functional and structural cell derangement. However, previous PET reports on age-related changes in resting brain glucose utilization (CMRglc) have been discrepant, presumably because of methodological as well as subject screening differences. In contrast to other studies, which used a region of interest approach, the objective of the present work was to determine, by means of the SPM software, the changes in regional CMRglc as a function of age in 24 optimally healthy, unmedicated volunteers of ages from 20 to 67 years. Global CMRglc showed a significant decline with age (approximately 6% per decade, P < 0.05), which concerned all the voxels studied save for most of the occipital cortex and part of the cerebellum. The most significant effects (P < 0.001) concerned the association neocortex in perisylvian temporoparietal and anterior temporal areas, the insula, the inferior and posterior-lateral frontal regions, the anterior cingulate cortex, the head of caudate nucleus, and the anterior thalamus, in a bilateral and essentially symmetrical fashion. The high posterior parietal cortex was not sampled in this study. This distribution of changes in CMRglc with age may differ from that seen in Alzheimer' disease, where the earliest metabolic reduction has been shown to affect the posterior cingulate cortex.
Collapse
|
45
|
Murphy DG, Mentis MJ, Pietrini P, Grady C, Daly E, Haxby JV, De La Granja M, Allen G, Largay K, White BJ, Powell CM, Horwitz B, Rapoport SI, Schapiro MB. A PET study of Turner's syndrome: effects of sex steroids and the X chromosome on brain. Biol Psychiatry 1997; 41:285-98. [PMID: 9024951 DOI: 10.1016/s0006-3223(95)00660-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Women with Turner's syndrome (TS) allow us to study the neurobiological associates of cognitive and behavioral abnormalities because they lack one/part of one X chromosome, and endogenous estrogen. We studied 13 healthy controls (mean age +/- SD, 28 +/- 6 years) and 16 TS subjects (mean age +/- SD, 26 +/- 6 years). We measured cognitive abilities using neuropsychological tests, and cerebral metabolic rates for glucose with positron emission tomography. Compared to controls, TS subjects had significant absolute hypermetabolism in most brain areas; however, normalized metabolism was significantly lower in TS subjects than controls in the insula and association neocortices bilaterally, and there were significant differences in functional metabolic associations of brain region pairs originating in occipital cortex bilaterally, and within the right hemisphere. There were significant correlations between right-left cognitive and metabolic asymmetries in the TS group. Also, within TS a preliminary analysis demonstrated "X chromosome dosage" effects in language ability and left temporal metabolism, asymmetry of right-left test scores, and parietal metabolism. We hypothesize that within TS: i) generalized brain hypermetabolism reflects global abnormalities in neuron packing; ii) neuronal abnormalities occur in association neocortex that differ in nature or extent from whole brain and are associated with significant differences in normalized metabolism; iii) cognitive deficits are related to brain metabolic abnormalities; and iv) social-behavioral problems may be related to abnormalities of brain metabolism. Moreover, in human brain the X chromosome involved in development of the association neocortices.
Collapse
Affiliation(s)
- D G Murphy
- Department of Psychological Medicine, Institute of Psychiatry, London, U.K
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Ludvig N. Microdialysis-coupled place cell detection in the hippocampus: a new strategy for the search for cognition enhancer drugs. Prog Neuropsychopharmacol Biol Psychiatry 1997; 21:249-71. [PMID: 9061773 DOI: 10.1016/s0278-5846(97)00001-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
1. The MPCD method in freely moving rats is a new neuroscience technique. It is able to detect the location-specific firing of hippocampal place cells, and to deliver, via microdialysis, various drug solutions into the extracellular environment of the detected neurons. Place cells are critical elements of the neural system in brain which governs cognitive processes. It is emphasized in this article that effective cognition enhancer drugs must selectively and significantly affect the firing of these cells. 2. By using MPCD, it is possible to recognize drug combinations which can increase the location-specific firing of place cells to an optimal level. This paper proposes that such pharmacological action facilitates engram-creation in extrahippocampal cortical areas, improving cognitive functions. Thus, an MPCD-based research strategy may lead to the rational development of a new generation of cognition enhancer drugs for the treatment of learning and memory disorders, including Alzheimer's disease (AD).
Collapse
Affiliation(s)
- N Ludvig
- Department of Physiology, State University of New York, Health Science Center at Brooklyn, USA
| |
Collapse
|
47
|
Abstract
Aging in humans may be accompanied by alterations in several functional abilities. However, there is a great deal of individual variability in the functions that may be altered with age within and across aged people. One potential source of age-related behavioral variation may lie in a differential vulnerability of neurobiological systems to the aging process in particular individuals. Aged monkeys demonstrate behavioral and brain alterations that have many parallels with those observed in aged humans and are valuable animal models in which to investigate the interrelationships between age, behavior and neurobiological measures. This review outlines the similarities of functional and neurobiological aging in monkeys and humans, notes the variability that exists in both behavioral and neural systems in aging, and identifies some of the areas of aging that are in need of further investigation.
Collapse
|
48
|
Abstract
Unlike other organs the energy requirement of the brain is met almost exclusively by aerobic glucose degradation (Siesjo, 1978). The energy requirement of the brain is 20–30% of the whole organism at rest, although its weight is only 2%. The energy stores in the brain are extremely small when compared with the high rate of glucose utilisation: thus the brain is reliant on a continuous glucose supply. Only about 30% of glucose is required for direct energy production; much of the remainder is used for the synthesis of amino acids, peptides, lipids and nucleic acids (Siebert, Gessner & Klasser, 1986). Thus a source of glucose is essential for the synthesis of physiologically active amines such as serotonin, noradrenaline and acetylcholine. Although it is well accepted that hypoglycaemia can result in the disruption of cognitive functioning, this is a rare phenomenon and it has usually been assumed that levels of blood glucose, within the normal range, do not influence intellectual functioning. This assumption is discussed in this paper.
Collapse
Affiliation(s)
- D Benton
- Department of Psychology, University of Wales Swansea
| | | | | |
Collapse
|
49
|
Parks RW, Becker RE, Rippey RF, Gilbert DG, Matthews JR, Kabatay E, Young CS, Vohs C, Danz V, Keim P, Collins GT, Zigler SS, Urycki PG. Increased regional cerebral glucose metabolism and semantic memory performance in Alzheimer's disease: a pilot double blind transdermal nicotine positron emission tomography study. Neuropsychol Rev 1996; 6:61-79. [PMID: 8976498 DOI: 10.1007/bf01875368] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Nicotinic receptor dysfunction and impaired semantic memory occur early in Alzheimer's disease patients (AD). Previous research implied that nicotine's ability to enhance alertness, arousal, and cognition in a number of nonclinical populations was a function of its ability to stimulate CNS nicotinic cholinergic receptors. In this study it was hypothesized that transdermal administration of nicotine would increase both regional cerebral glucose metabolism (rCMRglc) and semantic memory (as assessed by verbal fluency). Two mild AD and two elderly controls underwent positron emission tomography scanning during a double blind nicotinic agonist verbal fluency challenge procedure. rCMRglc increases occurred in both AD patients, but not controls. In the two AD patients, verbal fluency scores increased by an average of 17%. One elderly control's verbal fluency increased, and the other decreased. These findings suggest that nicotine's effect on metabolism and verbal fluency is due to its ability to stimulate the cholinergic system.
Collapse
Affiliation(s)
- R W Parks
- Department of Psychiatry, Southern Illinois University School of Medicine, Springfield and Carbondale 62794-1412, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Schapiro MB, Murphy DG, Hagerman RJ, Azari NP, Alexander GE, Miezejeski CM, Hinton VJ, Horwitz B, Haxby JV, Kumar A. Adult fragile X syndrome: neuropsychology, brain anatomy, and metabolism. AMERICAN JOURNAL OF MEDICAL GENETICS 1995; 60:480-93. [PMID: 8825884 DOI: 10.1002/ajmg.1320600603] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To understand the implications of suboptimal gene expression in fragile X syndrome -fra(X)-, we sought to define the central nervous abnormalities in fra(X) syndrome to determine if abnormalities in specific brain regions or networks might explain the cognitive and behavioral abnormalities in this syndrome. Cranial and ventricular volumes were measured with quantitative computed tomography (CT), regional cerebral metabolic rates for glucose (rCMRglc) were measured with [18-F]-2-fluoro-2-deoxy-D-glucose (18FDG), and patterns of cognition were determined with neuropsychological testing in ten healthy, male patients with karyotypically proven fra(X) syndrome (age range 20-30 yr). Controls for the CT studies were 20 healthy males (age range 21-37 yr), controls for the PET studies were 9 healthy males (age range 22-31 yr), and controls for the neuropsychological tests were 10 young adult, male Down syndrome (DS) subjects (age range 22-31 yr). The mean mental age of the fra(X) syndrome group was 5.3 yr (range 3.5-7.5 yr; Stanford-Binet Intelligence Scale). Despite comparable levels of mental retardation, the fra(X) subjects showed poorer attention/short term memory in comparison to the DS group. Further, the fra(X) subjects showed a relative strength in verbal compared to visuospatial attention/short term memory. As measured with quantitative CT, 8 fra(X) subjects had a significant (P < 0.05) 12% greater intracranial volume (1,410 +/- 86 cm3) as compared to controls (1,254 +/- 122 cm3). Volumes of the right and left lateral ventricles and the third ventricle did not differ between groups. Seven of eight patients had greater right lateral ventricle volumes than left, as opposed to 9 out of 20 controls (P < 0.05). Global gray matter CMR-glc in nine fra(X) patients was 9.79 +/- 1.28 mg/100 g/minute and did not differ from 8.84 +/- 1.31 mg/100 g/minute in the controls. R/L asymmetry in metabolism of the superior parietal lobe was significantly higher in the patients than controls. A preliminary principal component analysis of metabolic data showed that the fra(X) subjects tended to form a separate subgroup that is characterized by relative elevation of normalized metabolism in the lenticular nucleus, thalamus, and premotor regions. Further, a discriminant function, that reflected rCMRglc interactions of the right lenticular and left premotor regions, distinguished the fra(X) subjects from controls. These regions are part of a major group of functionally and anatomically related brain regions and appear disturbed as well in autism with which fra(X) has distinct behavioral similarities. These results show a cognitive profile in fra(X) syndrome that is distinct from that of Down syndrome, that the larger brains in fragile X syndrome are not accompanied by generalized cerebral cortical atrophy or hypoplasia, and that distinctive alterations in resting regional glucose metabolism, measured with 18 FDG and PET, occur in fra(X) syndrome.
Collapse
Affiliation(s)
- M B Schapiro
- Section on Brain Aging and Dementia, National Institute on Aging, Clinical Center, Bethesda, Maryland 20892, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|