Biology subjects

Bodammer, N. C.

Publications and source records attributed to Bodammer, N. C..

4 recordsLinked to original sources

bioRxiv2022

The integrity of dopaminergic and noradrenergic brain regions is associated with different aspects of late-life memory performance

Researchers have identified changes in dopaminergic neuromodulation as playing a key role in adult memory decline. Facilitated by technical advancements, recent research has also implicated noradrenergic neuromodulation in shaping late-life memory performance. However, it is not yet clear whether these two neuromodulators have distinct roles in age-related cognitive changes. Combining longitudinal high-resolution magnetic resonance imaging of the dopaminergic substantia nigra-ventral tegmental area (SN-VTA) and the noradrenergic locus coeruleus (LC) in younger (n = 69) and older adults (n = 251), we found that dopaminergic and noradrenergic integrity are differentially associated with individual differences in memory performance. While LC integrity was related to better episodic memory across several memory tasks, SN-VTA integrity was linked to working memory. Moreover, consistent with their dense interconnection and a largely shared biosynthesis, dopaminergic and noradrenergic brain regions integrity were positively related, and correlated with medial temporal lobe volumes. Longitudinally, we found that older age was associated with more-negative change in SN- VTA and LC integrity (time point 1-time point 2; mean delay [~]1.9 years). Importantly, changes in LC integrity reliably predicted future episodic memory performance (at time point 3). These findings support the feasibility of in-vivo indices for catecholaminergic integrity with potential clinical utility, given the degeneration of both neuromodulatory systems in several age-associated diseases. Moreover, they highlight differential roles of dopaminergic and noradrenergic neuromodulatory nuclei in late-life cognitive decline.

neuroscience↗

bioRxiv2022

Vamos en bici: Study protocol of an investigation of cognitive and neural changes following language training, physical exercise training, or a combination of both

As the relative number of elderly people as well as the average life expectancy increases, identifying potential means to alter the ongoing trajectory of aging and specifically the trajectory of cognitive performance is of great importance. Some modifiable lifestyle factors, such as physical and cognitive activity, have shown positive effects on cognition and brain structure, and the combination of the two might even show a boosted, interactive effect. In this study protocol, we describe in detail our data which was acquired to explore how cognitive stimulation in the form of acquiring a new language, physical exercise on stationary bikes or the combination of the two interventions affect brain structure, cognitive performance, and psychosocial functioning. One-hundred and forty-two older healthy adults (63-78 years) were randomly assigned to one of four six-month intervention programs, comprising (a) foreign language learning, (b) physical exercise training on a bicycle ergometer, (c) a combination of language learning and physical exercise, or (d) a book club (serving as an active control condition). We collected a rich neuroimaging data set, comprising T1-weighted structural, resting state functional, high resolution hippocampal, myelin water fraction, diffusion-weighted, arterial spin labeling, and multi-parameter images. Using a cognitive battery, we collected data from the domains of episodic memory, working memory, perceptual speed, and fluid intelligence. We performed comprehensive physical assessments including cardiopulmonary exercise testing, and additionally collected data on psychosocial functioning (e.g., well-being, perceived stress, control beliefs). We assume that physical activity boosts brain plasticity per se by inducing structural and neurochemical changes in brain regions that are important for learning and memory and therefore may facilitate the effects of cognitive training. (269 words)

neuroscience↗

bioRxiv2021

Reliability of quantitative multiparameter maps is high for MT and PD but attenuated for R1 and R2* in healthy young adults

We investigate the reliability of individual differences of four quantities measured by magnetic resonance imaging based multiparameter mapping (MPM): magnetization transfer (MT), proton density (PD), longitudinal relaxation rate (R1), and effective transverse relaxation rate (R2*). A total of four MPM datasets, two on each of two consecutive days, were acquired in healthy young adults. On Day 1, no repositioning occurred; on Day 2, participants were repositioned between MPM datasets. Using intra-class correlation effect decomposition (ICED), we assessed the contributions of session-specific, day-specific, and residual sources of measurement error. For whole-brain gray and white matter, all four MPM parameters showed high reproducibility and high reliability, as indexed by the coefficient of variation (CoV) and the intra-class correlation (ICC). However, MT, PD, R1, and R2* differed markedly in the extent to which reliability varied across brain regions. MT and PD showed high reliability in almost all regions. In contrast, R1 and R2* showed low reliability in some regions outside the basal ganglia, such that the sum of the measurement error estimates in our structural equation model was higher than estimates of between-person differences. In sum, in this sample of healthy young adults, the four MPM parameters showed very little variability over four measurements over two days but differed in how well they could assess between-person differences. We conclude that R1 and R2* might carry only limited person-specific information in samples of healthy young adults, and, by implication, might be of restricted utility for studying associations to between-person differences in behavior.

neuroscience↗

bioRxiv2018

Locus coeruleus integrity preserves memory performance across the adult life span

For decades, research into memory decline in human cognitive aging has focused on neocortical regions, the hippocampus, and dopaminergic neuromodulation. Recent findings indicate that the locus coeruleus (LC) and noradrenergic neuromodulation may also play an important role in shaping memory development in later life. However, technical challenges in quantifying LC integrity have hindered the study of LC-cognition associations in humans. Using high-resolution neuromelanin-sensitive magnetic resonance imaging, we found that individual differences in learning and memory were positively associated with LC integrity across a variety of memory tasks in younger (n = 66), and older adults (n = 228). Moreover, we observed functionally relevant age differences confined to rostral LC. Older adults with a more youth-like rostral LC also showed higher memory performance. These findings link non-invasive, in vivo indices of LC integrity to memory in aging and highlight the role of the LC norepinephrine system in the decline of cognition.

neuroscience↗