Normal aging is associated with cognitive decline. Functions such as attention, information processing, and working memory are compromised. It has been hypothesized that not only regional changes, ...but also alterations in the integration of regional brain activity (functional brain connectivity) underlie the observed age-related deficits. Here, we examined the functional properties of brain networks based on spontaneous fluctuations within brain systems using functional magnetic resonance imaging. We hypothesized that functional connectivity of intrinsic brain activity in the “default-mode” network (DMN) is affected by normal aging and that this relates to cognitive function. Ten younger and 22 older subjects were scanned at “rest,” that is, lying awake with eyes closed. Our results show decreased activity in older versus younger subjects in 2 resting-state networks (RSNs) resembling the previously described DMN, containing the superior and middle frontal gyrus, posterior cingulate, middle temporal gyrus, and the superior parietal region. These results remain significant after correction for RSN-specific gray matter volume. The relevance of these findings is illustrated by the correlation between reduced activity of one of these RSNs and less effective executive functioning/processing speed in the older group.
Though insomnia is associated with affected emotion regulation and dysfunctional ideas about sleep, little is known about the relation of these problems with objective sleep disruption. We aimed to ...explore this relationship in young adults with and without insomnia.
Twenty young adults with diagnosed insomnia disorder (aged 27.7 ± 8.6 years) and twenty age-matched individuals without insomnia (26.7 ± 7.0 years) completed questionnaires, measuring sleep-related thoughts and emotions and emotion regulation. Objective sleep measurements were collected through 10-days actigraphy as a representative sample of nights, and analyzed for sleep onset latency, sleep efficiency total sleep time. T-tests and multivariate analyses of variance (MANOVA) were conducted for sample characterization and analysis of the association of sleep-related thoughts and emotions and emotion regulation with objective sleep data.
As expected, young people showed more dysfunctional sleep-related thoughts and emotions (all ps ≤ 0.025) and dysfunctional emotion regulation strategies (all ps ≤ 0.040). Surprisingly, MANOVA results showed that only emotion coping strategies after a stressful event (p = 0.017) and dysfunctional beliefs about sleep (p = 0.012), but not other factors of arousal or sleep reactivity, were associated with overall worse sleep, especially sleep onset latency (all ps ≤ 0.012) and sleep efficiency (all ps ≤ 0.010).
Maladaptive emotion coping strategies after a stressful event and dysfunctional sleep-related beliefs and attitudes affect objective sleep onset latency and sleep efficiency in young adults, highlighting the importance of targeting these features in the prevention and treatment of chronic insomnia and improving actual sleep quality.
•Affected sleep in young adults is particularly related to emotion coping strategies and sleep-related beliefs and attitudes.•This relation was particularly strong for sleep onset latency and sleep efficiency, but not for total sleep time.•Insomnia treatment in young adults should focus more on emotion coping strategies and ideas about sleep.
In human brain imaging studies, it is common practice to use the Talairach stereotaxic reference system for signifying the convergence of brain function and structure. In nearly all neuroimaging ...reports, the studied cortical areas are specified further with a Brodmann Area (BA) number. This specification is based upon macroscopic extrapolation from Brodmann's projection maps into the Talairach atlas rather than upon a real microscopic cytoarchitectonic study. In this review we argue that such a specification of Brodmann area(s) via the Talairach atlas is not appropriate. Cytoarchitectonic studies reviewed in this paper show large interindividual differences in 3-D location of primary sensory cortical areas (visual cortex) as well as heteromodal associational areas (prefrontal cortical areas), even after correction for differences in brain size and shape. Thus, the simple use of Brodmann cortical areas derived from the Talairach atlas can lead to erroneous results in the specification of pertinent BA. This in turn can further lead to wrong hypotheses on brain system(s) involved in normal functions or in specific brain disorders. In addition, we will briefly discuss the different 'Brodmann' nomenclatures which are in use for the cerebral cortex.
On MR imaging, white matter hyperintensities (WMH) on T2-weighted images are generally considered as a surrogate marker of ischemic small vessel disease in elderly subjects. Pulsed arterial ...spin-labeling (PASL) is a noninvasive MR perfusion-weighted technique. We hypothesized that elderly subjects with diffuse confluent WMH should have lower cerebral blood flow (CBF) measurements than subjects with punctiform or beginning confluent WMH.
MR images of 21 subjects (13 women; mean age, 76 years; SD, 5), stratified for the degree of WMH, from a single center within the multinational Leukoaraiosis and Disability (LADIS) study, were investigated. CBF images were obtained by means of quantitative imaging of perfusion by using a single-subtraction second version, with thin-section TI periodic saturation PASL. Values of cortical gray matter, subcortical (including white matter and deep gray matter), and global CBF were calculated. CBF measurements of subjects with diffuse confluent WMH (n = 7) were compared with those of subjects with punctiform or beginning confluent WMH (n = 14).
Subjects with diffuse confluent WMH were found to have approximately 20% lower mean global CBF (43.5 mL/100 mL/min; SD, 6.3) than subjects with punctiform or beginning confluent WMH (57.9 mL/100 mL/min; SD, 8.6; P < .01), as well as approximately 20% lower mean subcortical (P < .01) and cortical gray matter CBF (P < .05).
PASL revealed a significant reduction of CBF measurements in elderly subjects with diffuse confluent WMH.
OBJECTIVE: Structural deficits in the anterior cingulate cortex such as changes in glial cell and neuron numbers may be part of the anatomical substrate for schizophrenia and need to be investigated. ...The total number of neurons and glial cells in brains of 12 schizophrenia subjects and 14 comparison subjects were determined in two subdivisions of the prefrontal cortex: Brodmann's area 24, a part of the anterior cingulate cortex, and Brodmann's area 32 in the paracingulate cortex. METHOD: The estimate of the total cell number was obtained by multiplying the volume of the region (estimated by using Cavalieri's point counting method) by the numerical density obtained from optical disectors in the cytoarchitectonically defined areas from the prefrontal cortex. RESULTS: The average total of bilateral glial cells in Brodmann's area 24 was 201×106 in subjects with schizophrenia and 302×106 in comparison subjects, a statistically significant difference of 33%, whereas there was a nonsignificant difference between the schizophrenia subjects and the comparison subjects in total number of glial cells in Brodmann's area 32. The bilateral average total number of neurons in areas 24 and 32 did not differ significantly between the schizophrenia and comparison subjects. CONCLUSIONS: A selective reduction in glial cells in Brodmann's area 24 (but not in area 32) is seen in brains of subjects with schizophrenia relative to those of comparison subjects. Further investigations of the glial cells, their mutual relationship, and their relationship with neurons are needed to understand the role of specific glial components in this mental disorder.
The primate cingulate cortex is structurally and functionally complex. Although no studies have investigated the regional densities of multiple neurotransmitter receptor systems, such information ...would be useful for assessing its functions and disease vulnerabilities. We quantified nine different receptors in five transmitter systems by in vitro autoradiographic mapping of the cingulate cortex of macaque monkeys with the aim to link cytoarchitectonic regions and functional specialization. Receptor mapping substantiated the subdivision of the cingulate cortex into anterior versus posterior regions. In anterior cingulate cortex (ACC) AMPA glutamatergic receptors and GABA
A inhibitory receptors were present in significantly higher concentrations than the modulatory α-adrenergic and muscarinic receptors. These differences were absent in the posterior cingulate cortex (PCC). By contrast, NMDA receptor densities were significantly higher than AMPA receptor densities in PCC, but not in ACC. The midcingulate area 24′ shared more features with ACC than PCC. This area was characterized by the highest ratios of NMDA receptors to α-adrenergic, muscarinic and 5-HT
2 receptors among all cingulate regions. Compared to rostrocaudal divisions, the differences between dorsoventral subdivisions a–c were small in all regions of cingulate cortex, and only muscarinic and α-adrenergic receptor densities followed the degree of cytoarchitectonic differentiation. We conclude that multiple receptor mapping reveals a highly differentiated classification of cingulate cortex with a characteristic predominance of fast ionotropic excitatory and inhibitory receptors in ACC, but a strong and varied complement of NMDA and metabotropic receptors in PCC.
Methods We compared the performance and brain activity patterns elicited during the performance of a self-paced Tower of London task in fMRI (1.5T Siemens Sonata, 3mm isotropic voxels, TR 3.5, TE 60, ...35 slices) of chronic insomnia patients (n= 24) to those of healthy well-sleeping age-matched control participants (n= 13).
In AD, both selective decreases and increases in brain activity have been reported (4-7). ...the consequences of AD are not only related to local functional loss and directly connected brain regions, ...but also involve abnormal or compensatory reorganizations of global functional networks.
Introduction In Multiple Sclerosis (MS) gender is known to impact the disease (Roth et al., 1994), and recently this gender effect was demonstrated using MRI (Antulov et al., 2008). Because evidence ...of a gender effect in MS is so far limited to structural MRI measures, such as atrophy, our study investigates (resting state) functional MRI using a graph analysis approach. Conclusions This pilot study shows that a gender difference in synchronisation and path length apparent in healthy controls is lost in MS patients. ...our results may imply that these measures of functional connectivity are more affected in MS males than in MS females.
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