Diminished Posterior Precuneus Connectivity with the Default Mode Network Differentiates Normal Aging from Alzheimer's Disease

Multivariate analysis of psychological dat

Imaging functional brain connectivity : pharmacological modulation, aging and Alzheimer's disease

The main objective of this thesis was to investigate the serotonergic and cholinergic neurotransmitter systems, and the way these are altered in older age and Alzheimer’s disease. For that purpose, the neuroimaging technique resting state fMRI (RS-fMRI) was used to measure whole brain functional connectivity with and without pharmacological stimulation. The first part of the thesis concerns two pharmacological RS-fMRI studies that were executed in young adults. Pharmacological challenge effects of two selective serotonin reuptake inhibitors (sertraline and citalopram) and a cholinesterase inhibitor (galantamine) on brain connectivity were examined to gain more insight into the underlying neurotransmitter systems and the mechanisms of drug action in the central nervous system. The second part of this thesis was aimed at discovering changes in brain connectivity and serotonergic and cholinergic system functioning in aging and Alzheimer’s disease, by comparing brain network connections and the pharmacological response of this measure between young and older adults and patients with Alzheimer’s disease.Multivariate analysis of psychological dat

Imaging functional brain connectivity : pharmacological modulation, aging and Alzheimer's disease

The main objective of this thesis was to investigate the serotonergic and cholinergic neurotransmitter systems, and the way these are altered in older age and Alzheimer’s disease. For that purpose, the neuroimaging technique resting state fMRI (RS-fMRI) was used to measure whole brain functional connectivity with and without pharmacological stimulation. The first part of the thesis concerns two pharmacological RS-fMRI studies that were executed in young adults. Pharmacological challenge effects of two selective serotonin reuptake inhibitors (sertraline and citalopram) and a cholinesterase inhibitor (galantamine) on brain connectivity were examined to gain more insight into the underlying neurotransmitter systems and the mechanisms of drug action in the central nervous system. The second part of this thesis was aimed at discovering changes in brain connectivity and serotonergic and cholinergic system functioning in aging and Alzheimer’s disease, by comparing brain network connections and the pharmacological response of this measure between young and older adults and patients with Alzheimer’s disease.</p

Outcome of a recruitment campaign for subjects at risk for Alzheimer's disease in the Netherlands

Multivariate analysis of psychological dat

Cholinergic and serotonergic modulation of resting state functional brain connectivity in Alzheimer's disease

Neuro Imaging Researc

Serotonergic and cholinergic modulation of functional brain connectivity: A comparison between young and older adults

Aging is accompanied by changes in neurotransmission. To advance our understanding of how aging modifies specific neural circuitries, we examined serotonergic and cholinergic stimulation with resting state functional magnetic resonance imaging (RS-fMRI) in young and older adults. The instant response to the selective serotonin reuptake inhibitor citalopram (30 mg) and the acetylcholinesterase inhibitor galantamine (8 mg) was measured in 12 young and 17 older volunteers during a randomized, double blind, placebo-controlled, crossover study. A powerful dataset consisting of 522 RS-fMRI scans was obtained by acquiring multiple scans per subject before and after drug administration. Group x treatment interaction effects on voxelwise connectivity with ten functional networks were investigated (p < .05, FWE-corrected) using a non-parametric multivariate analysis technique with cerebrospinal fluid, white matter, heart rate and baseline measurements as covariates. Both groups showed a decrease in sensorimotor network connectivity after citalopram administration. The comparable findings after citalopram intake are possibly due to relatively similar serotonergic systems in the young and older subjects. Galantamine altered connectivity between the occipital visual network and regions that are implicated in learning and memory in the young subjects. The lack of a cholinergic response in the elderly might relate to the well-known association between cognitive and cholinergic deterioration at older age.Neuro Imaging Researc

Diminished Posterior Precuneus Connectivity with the Default Mode Network Differentiates Normal Aging from Alzheimer's Disease

Stress-related psychiatric disorders across the life spa

Single-dose serotonergic stimulation shows widespread effects on functional brain connectivity

The serotonergic system is widely distributed throughout the central nervous system. It is well known as a mood regulating system, although it also contributes to many other functions. With resting state functional magnetic resonance imaging (RS-fMRI) it is possible to investigate whole brain functional connectivity. We used this non-invasive neuroimaging technique to measure acute pharmacological effects of the selective serotonin reuptake inhibitor sertraline (75 mg) in 12 healthy volunteers. In this randomized, double blind, placebo-controlled, crossover study, RS-fMRI scans were repeatedly acquired during both visits (at baseline and 3, 5, 7 and 9 h after administering sertraline or placebo). Within-group comparisons of voxelwise functional connectivity with ten functional networks were examined (p < 0.005, corrected) using a mixed effects model with cerebrospinal fluid, white matter, motion parameters, heart rate and respiration as covariates. Sertraline induced widespread effects on functional connectivity with multiple networks; the default mode network, the executive control network, visual networks, the sensorimotor network and the auditory network. A common factor among these networks was the involvement of the precuneus and posterior cingulate cortex. Cognitive and subjective measures were taken as well, but yielded no significant treatment effects, emphasizing the sensitivity of RS-fMRI to pharmacological challenges. The results are consistent with the existence of an extensive serotonergic system relating to multiple brain functions with a possible key role for the precuneus and cingulate

Single-dose serotonergic stimulation shows widespread effects on functional brain connectivity

Neuro Imaging Researc