Functional magnetic resonance imaging (fMRI) studies of the medial temporal lobe have primarily made use of the blood oxygenation level dependent (BOLD) response to neural activity. The interpretation of the BOLD signal as a measure of medial temporal lobe function can be complicated, however, by changes in the cerebrovascular system that can occur with both normal aging and age-related diseases, such as Alzheimer's disease. Quantitative measures of the functional cerebral blood flow (CBF) response offer a useful complement to BOLD measures and have been shown to aid in the interpretation of fMRI studies. Despite these potential advantages, the application of ASL to fMRI studies of cognitive tasks and at-risk populations has been limited. In this study, we demonstrate the application of ASL fMRI to obtain measures of the CBF and BOLD responses to the encoding of natural scenes in healthy young (mean 25 years) and elderly (mean 74 years) adults. The percent CBF increase in the medial temporal lobe was significantly higher in the older adults, whereas the CBF levels during baseline and task conditions and during a separate resting-state scan were significantly lower in the older group. The older adults also showed slightly higher values for the BOLD response amplitude and the absolute change in CBF, but the age group differences were not significant. The percent CBF and BOLD responses are consistent with an age-related increase in the cerebral metabolic rate of oxygen metabolism (CMRO(2)) response to memory encoding.
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http://dx.doi.org/10.1016/j.neuroimage.2007.05.024 | DOI Listing |
Methods Cell Biol
January 2025
Translational Radiomics, Luxembourg Institute of Health, Luxembourg City, Luxembourg; In-Vivo Imaging Platform, Luxembourg Institute of Health, Luxembourg City, Luxembourg.
During hypoxia, tissues are subjected to an inadequate oxygen supply, disrupting the balance needed to maintain normal function. This deficiency can occur due to reduced oxygen delivery caused by impaired blood flow or a decline in the blood's ability to carry oxygen. In tumors, hypoxia and vascularization play crucial roles, shaping their microenvironments and influencing cancer progression, response to treatment and metastatic potential.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
Department of Animal Biosciences, University of Guelph, Guelph, Ontario, N1G 2W1, Canada. Electronic address:
Provision of supplemental concentrate in an automated milking system (AMS) is commonly used to encourage voluntary attendance, however, the motivation to voluntarily milk is highly variable between cows. The objectives of this study were to determine if dairy cow personality is associated with: 1) their short-term response to changes in factors believed to motivate voluntary AMS visits such as udder pressure and provision of supplemental feed (modulated by longer milking intervals or removal of AMS concentrate, respectively); and 2) their milking activity, production, and feeding behavior after returning to pre-treatment AMS milking interval and concentrate feed settings (i.e.
View Article and Find Full Text PDFHorm Behav
January 2025
Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, United States of America. Electronic address:
Individual variation in stress coping styles is widespread and consequential to health and fitness. Proactive (bold behavior, low stress reactivity, low cognitive flexibility) and reactive (shy behavior, high stress reactivity, high cognitive flexibility) coping styles are found in many species, but the developmental forces shaping them remain elusive. We examined how social influences, specifically mating interactions, shape the development of adult female coping styles with a manipulative rearing experiment using El Abra swordtails, Xiphophorus nigrensis.
View Article and Find Full Text PDFJ Neurosci
January 2025
The Neuroscience Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, USA
Reciprocal neuronal connections exist between the internal organs of the body and the nervous system. These projections to and from the viscera play an essential role in maintaining and finetuning organ responses in order to sustain homeostasis and allostasis. Functional maps of brain regions participating in this bidirectional communication have been previously studied in awake humans and anesthetized rodents.
View Article and Find Full Text PDFJ Food Sci
January 2025
Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon, USA.
This research explores consumer preferences and emotional reactions to beverages made from roasted barley and examines the possibility of launching a new product line featuring Streaker barley grown in the Pacific Northwest. Utilizing hedonic scales, just-about-right scales, and check-all-that-apply questions, a sensory evaluation was conducted. The study reveals two distinct consumer clusters, each exhibiting contrasting preferences and responses to novel beverages incorporating Streaker barley.
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