scholarly journals Brain imaging and human nutrition: which measures to use in intervention studies?

2013 ◽  
Vol 110 (S1) ◽  
pp. S1-S30 ◽  
Author(s):  
Stéphane V. Sizonenko ◽  
Claudio Babiloni ◽  
Eveline A. de Bruin ◽  
Elizabeth B. Isaacs ◽  
Lena S. Jönsson ◽  
...  

The present review describes brain imaging technologies that can be used to assess the effects of nutritional interventions in human subjects. Specifically, we summarise the biological relevance of their outcome measures, practical use and feasibility, and recommended use in short- and long-term nutritional studies. The brain imaging technologies described consist of MRI, including diffusion tensor imaging, magnetic resonance spectroscopy and functional MRI, as well as electroencephalography/magnetoencephalography, near-IR spectroscopy, positron emission tomography and single-photon emission computerised tomography. In nutritional interventions and across the lifespan, brain imaging can detect macro- and microstructural, functional, electrophysiological and metabolic changes linked to broader functional outcomes, such as cognition. Imaging markers can be considered as specific for one or several brain processes and as surrogate instrumental endpoints that may provide sensitive measures of short- and long-term effects. For the majority of imaging measures, little information is available regarding their correlation with functional endpoints in healthy subjects; therefore, imaging markers generally cannot replace clinical endpoints that reflect the overall capacity of the brain to behaviourally respond to specific situations and stimuli. The principal added value of brain imaging measures for human nutritional intervention studies is their ability to provide uniquein vivoinformation on the working mechanism of an intervention in hypothesis-driven research. Selection of brain imaging techniques and target markers within a given technique should mainly depend on the hypothesis regarding the mechanism of action of the intervention, level (structural, metabolic or functional) and anticipated timescale of the intervention's effects, target population, availability and costs of the techniques.

2015 ◽  
Vol 28 (2) ◽  
pp. 61-74 ◽  
Author(s):  
George Franklin ◽  
Alan J Carson ◽  
Killian A. Welch

ObjectiveAlthough cognitive behavioural therapy (CBT) has been shown to be an effective treatment for depression, the biological mechanisms underpinning it are less clear. This review examines if it is associated with changes identifiable with current brain imaging technologies.MethodsTo better understand the mechanisms by which CBT exerts its effects, we undertook a systematic review of studies examining brain imaging changes associated with CBT treatment of depression.ResultsTen studies were identified, five applying functional magnetic resonance imaging, three positron emission tomography, one single photon emission computer tomography, and one magnetic resonance spectroscopy. No studies used structural MRI. Eight studies included a comparator group; in only one of these studies was there randomised allocation to another treatment. CBT-associated changes were most commonly observed in the anterior cingulate cortex (ACC), posterior cingulate, ventromedial prefrontal cortex/orbitofrontal cortex (VMPFC/OFC) and amygdala/hippocampus.DiscussionThe evidence, such as it is, suggests resting state activity in the dorsal ACC is decreased by CBT. It has previously been suggested that treatment with CBT may result in increased efficiency of a putative ‘dorsal cognitive circuit’, important in cognitive control and effortful regulation of emotion. It is speculated this results in an increased capacity for ‘top-down’ emotion regulation, which is employed when skills taught in CBT are engaged. Though changes in activity of the dorsal ACC could be seen as in-keeping with this model, the data are currently insufficient to make definitive statements about how CBT exerts its effects. Data do support the contention that CBT is associated with biological brain changes detectable with current imaging technologies.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250079
Author(s):  
Fernanda Ferreira Evangelista ◽  
Willian Costa-Ferreira ◽  
Francini Martini Mantelo ◽  
Lucimara Fátima Beletini ◽  
Amanda Hinobu de Souza ◽  
...  

The aim of this study was to investigate the effect of rosuvastatin treatment on memory impairment, and anxiogenic-like effects in mice chronically infected with Toxoplasma gondii. For this, Balb/c mice were infected orally with chronic ME-49 strain of Toxoplasma gondii. Oral treatment with rosuvastatin (40mg/kg/day) started on the 51st day post-infection and was performed daily for 21 days. After completion of treatment, anxiety-like effects and locomotion were investigated in the open field (OF) test, whereas novel object recognition (NOR) test was used for evaluation of short- and long-term memory. At the end of the experiments, the brain was collected for Toxoplasma gondii DNA quantification and histopathological analysis. Infection with ME-49 strain decreased the time spent in the center of OF, indicating an anxiogenic effect, without affecting total and peripheral locomotion. Rosuvastatin treatment inhibited the change in the center time. Besides, pharmacological treatment increased total and central locomotion in both non-infected and infected animals. Infection also impaired both short- and long-term memory in the NOR test, and these effects were reverted by rosuvastatin treatment. In addition to effects in behavioral changes, rosuvastatin also reduced parasite load in the brain and attenuated signs of brain inflammation such as perivascular cuffs, inflammatory cell infiltration and tissue damage. These findings indicate for the first time the efficacy of rosuvastatin in treatment of memory impairment and anxiogenic effect evoked by infection with Toxoplasma gondii. These effects might be mediated by reduced cyst load, which in turn decrease inflammation and damage in the brain.


2017 ◽  
Author(s):  
Michael P. Milham ◽  
R. Cameron Craddock ◽  
Arno Klein

AbstractDespite decades of research, visions of transforming neuropsychiatry through the development of brain imaging-based ‘growth charts’ or ‘lab tests’ have remained out of reach. In recent years, there is renewed enthusiasm about the prospect of achieving clinically useful tools capable of aiding the diagnosis and management of neuropsychiatric disorders. The present work explores the basis for this enthusiasm. We assert that there is no single advance that currently has the potential to drive the field of clinical brain imaging forward. Instead, there has been a constellation of advances that, if combined, could lead to the identification of objective brain imaging-based markers of illness. In particular, we focus on advances that are helping to: 1) elucidate the research agenda for biological psychiatry (e.g., neuroscience focus, precision medicine), 2) shift research models for clinical brain imaging (e.g., big data exploration, standardization), 3) break down research silos (e.g., open science, calls for reproducibility and transparency), and 4) improve imaging technologies and methods. While an arduous road remains ahead, these advances are repositioning the brain imaging community for long-term success.


2021 ◽  
Vol 11 ◽  
Author(s):  
Kıvılcım Kılıç ◽  
Michèle Desjardins ◽  
Jianbo Tang ◽  
Martin Thunemann ◽  
Smrithi Sunil ◽  
...  

Chronic cranial windows allow for longitudinal brain imaging experiments in awake, behaving mice. Different imaging technologies have their unique advantages and combining multiple imaging modalities offers measurements of a wide spectrum of neuronal, glial, vascular, and metabolic parameters needed for comprehensive investigation of physiological and pathophysiological mechanisms. Here, we detail a suite of surgical techniques for installation of different cranial windows targeted for specific imaging technologies and their combination. Following these techniques and practices will yield higher experimental success and reproducibility of results.


2002 ◽  
Vol 88 (2) ◽  
pp. 991-1004 ◽  
Author(s):  
Rieko Osu ◽  
David W. Franklin ◽  
Hiroko Kato ◽  
Hiroaki Gomi ◽  
Kazuhisa Domen ◽  
...  

In the field of motor control, two hypotheses have been controversial: whether the brain acquires internal models that generate accurate motor commands, or whether the brain avoids this by using the viscoelasticity of musculoskeletal system. Recent observations on relatively low stiffness during trained movements support the existence of internal models. However, no study has revealed the decrease in viscoelasticity associated with learning that would imply improvement of internal models as well as synergy between the two hypothetical mechanisms. Previously observed decreases in electromyogram (EMG) might have other explanations, such as trajectory modifications that reduce joint torques. To circumvent such complications, we required strict trajectory control and examined only successful trials having identical trajectory and torque profiles. Subjects were asked to perform a hand movement in unison with a target moving along a specified and unusual trajectory, with shoulder and elbow in the horizontal plane at the shoulder level. To evaluate joint viscoelasticity during the learning of this movement, we proposed an index of muscle co-contraction around the joint (IMCJ). The IMCJ was defined as the summation of the absolute values of antagonistic muscle torques around the joint and computed from the linear relation between surface EMG and joint torque. The IMCJ during isometric contraction, as well as during movements, was confirmed to correlate well with joint stiffness estimated using the conventional method, i.e., applying mechanical perturbations. Accordingly, the IMCJ during the learning of the movement was computed for each joint of each trial using estimated EMG-torque relationship. At the same time, the performance error for each trial was specified as the root mean square of the distance between the target and hand at each time step over the entire trajectory. The time-series data of IMCJ and performance error were decomposed into long-term components that showed decreases in IMCJ in accordance with learning with little change in the trajectory and short-term interactions between the IMCJ and performance error. A cross-correlation analysis and impulse responses both suggested that higher IMCJs follow poor performances, and lower IMCJs follow good performances within a few successive trials. Our results support the hypothesis that viscoelasticity contributes more when internal models are inaccurate, while internal models contribute more after the completion of learning. It is demonstrated that the CNS regulates viscoelasticity on a short- and long-term basis depending on performance error and finally acquires smooth and accurate movements while maintaining stability during the entire learning process.


2004 ◽  
Vol 16 (4) ◽  
pp. 491 ◽  
Author(s):  
G. B. Martin ◽  
J. Rodger ◽  
D. Blache

Animals live in environments that are both complex and continually changing, so they have to respond to short- and long-term variations in a wide range of factors, such as photoperiod, nutrition and sociosexual signals. Before they were domesticated, animals developed reproductive strategies that coped with these changes and often took advantage of them. The physiological processes that implement these strategies have been modified to some extent during several millennia of controlled breeding, but most persist. Thus, many genotypes still exhibit profound responses to external inputs, such as the induction of ovulation by sociosexual signals and the doubling of litter size by a change in nutrition. The complexity in these responses is now becoming clearer. For example, with sociosexual signals, we now need to consider the stimulatory effects of males on females, of females on males and of females on females. Similarly, the impact of nutrition has been extended beyond the control of puberty and the production of gametes to include phenomena such as ‘fetal programming’, with its potentially profound effects on the life-long performance of the animals. Fortunately, our capacity to research these phenomena has been greatly enhanced by technical improvements in hormone assays, molecular and cellular biology, and real-time ultrasound. This has brought us a better understanding of several of the environmental influences on reproduction, including: the cellular processes within ovarian follicles that mediate the effect of nutrition on ovulation rate; the neuroendocrine pathways through which nutritional inputs affect the brain centres that control appetite and reproduction; and the intracerebral pathways through which sociosexual signals (olfactory and non-olfactory) stimulate the reproductive axis. Importantly, we are now beginning to realise that, as well as considering interactions between environmental inputs and genotype, we need to take into account interactions between the environmental factors themselves, just as the animals do. We still have a long way to go for a complete understanding, but we are nevertheless in a position where we can begin to use this information to develop new management systems for our animals to improve their productivity.


Author(s):  
Asghar Rezaei ◽  
Ghodrat Karami ◽  
Fardad Azarmi ◽  
Mehdi Salimi Jazi ◽  
Mariusz Ziejewski

This research is intended to examine the amount of changes that can happen in material characteristics after retesting. Stress relaxation test is conducted on the same samples of the swine brain tissue for several times in small and large deformations. The mechanical properties of the substance are calculated before and after retest and the constants of the tissue, as mechanical characteristics, are determined and compared. Short- and long-term moduli, relaxation times and relaxation functions are of those data that are calculated and compared to understand how much they decay after repeating the experiments. The results show that applying different tests on one sample slightly changes the mechanical properties of the tissue and, as a result, it is partly possible to perform more than one test on the same sample resulting in less sample preparation, time and effort.


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