: Functional deregulation of dopaminergic midbrain regions is a core feature of schizophrenia pathophysiology. Anatomical research on primates suggests that these regions may be subdivided into distinct, topographically organized functional territories according to their connectivity to the striatum. The aim of the present work was the reconstruction of dopaminergic midbrain subregions in healthy subjects and schizophrenic patients and the evaluation of their structural connectivity profiles. : A hypothesis-driven connectivity-based parcellation derived from diffusion tractography was applied on 24 healthy subjects and 30 schizophrenic patients to identify distinct territories within the human dopaminergic midbrain in vivo and non-invasively. : We identified a tripartite subdivision of dopaminergic midbrain, including limbic, prefrontal and sensorimotor territories. No significant differences in structural features or connectivity were found between subjects and patients. : The parcellation scheme proposed herein may help to achieve detailed characterization of structural and functional anomalies of the dopaminergic midbrain in schizophrenic patients.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7764101 | PMC |
http://dx.doi.org/10.3390/medicina56120686 | DOI Listing |
Brain Sci
December 2024
Nepean Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2751, Australia.
Background: Amphetamines increase dopamine levels in mid-brain regions which, in turn, impact top-down executive function. Repeated exposure is linked to substance use disorders. Nonetheless, amphetamines are used to manage attention-deficit/hyperactivity disorder (ADHD) and eating-related disorders.
View Article and Find Full Text PDFHum Brain Mapp
January 2025
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, Magdeburg, Germany.
The present study investigated the neuromodulatory substrates of salience processing and its impact on memory encoding and behaviour, with a specific focus on two distinct types of salience: reward and contextual unexpectedness. 46 Participants performed a novel task paradigm modulating these two aspects independently and allowing for investigating their distinct and interactive effects on memory encoding while undergoing high-resolution fMRI. By using advanced image processing techniques tailored to examine midbrain and brainstem nuclei with high precision, our study additionally aimed to elucidate differential activation patterns in subcortical nuclei in response to reward-associated and contextually unexpected stimuli, including distinct pathways involving in particular dopaminergic modulation.
View Article and Find Full Text PDFIn Parkinson's disease, dopaminergic neurons (DANs) in the midbrain gradually degenerate, with ventral substantia nigra pars compacta (SNc) DANs exhibiting greater vulnerability. However, it remains unclear whether specific molecular subtypes of ventral SNc DANs are more susceptible to degeneration in PD, and if they contribute to the early motor symptoms associated with the disease. We identified a subtype of Sox6+ DANs, Anxa1+, which are selectively lost earlier than other DANs, and with a time course that aligns with the development of motor symptoms in MitoPark mice.
View Article and Find Full Text PDFThe degeneration of midbrain dopamine (DA) neurons disrupts the neural control of natural behavior, such as walking, posture, and gait in Parkinson's disease. While some aspects of motor symptoms can be managed by dopamine replacement therapies, others respond poorly. Recent advancements in machine learning-based technologies offer opportunities for unbiased segmentation and quantification of natural behavior in both healthy and diseased states.
View Article and Find Full Text PDFMol Cell Biochem
January 2025
Neurodegenerative Diseases Laboratory, Center for Biomedicine, Universidad Mayor, Avenida Alemania 0281, 4780000, Temuco, La Araucanía, Chile.
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by tremor, rigidity, and bradykinesia, beginning with early loss of dopaminergic neurons in the ventrolateral substantia nigra and advancing to broader neurodegeneration in the midbrain. The clinical heterogeneity of PD and the lack of specific diagnostic tests present significant challenges, highlighting the need for reliable biomarkers for early diagnosis. Alpha-synuclein (α-Syn), a protein aggregating into Lewy bodies and neurites in PD patients, has emerged as a key biomarker due to its central role in PD pathophysiology and potential to reflect pathological processes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!