AI Article Synopsis
- The study used functional MRI to examine how the brain responds to an object-location learning task in 24 healthy elderly individuals, revealing that brain activation adjusts based on the task's difficulty and the amount of practice.
- Scopolamine, sulpiride, and methylphenidate reduced brain response to increased cognitive load, while diazepam enhanced the effects of practice without influencing the load response.
- Findings suggest that different neurotransmitter systems mediate the brain's adaptive mechanisms for handling task difficulty and practice, highlighting distinct activation patterns in brain regions related to cognitive function.
Article Abstract
Brain activation is adaptive to task difficulty and practice. We used functional MRI to map brain systems activated by an object-location learning task in 24 healthy elderly volunteers each scanned following placebo and two of four active drugs studied. We distinguished a fronto-striatal system adaptive to difficulty from a posterior system adaptive to practice. Fronto-striatal response to increased cognitive load was significantly attenuated by scopolamine, sulpiride and methylphenidate; practice effects were not modulated by these drugs but were enhanced by diazepam. We also found enhancement by methylphenidate, and attenuation by sulpiride, of load response in premotor, cingulate and parietal regions comprising a spatial attention network. Difficulty and practice evoke anatomically and pharmacologically dissociable brain activation dynamics, which are probably mediated by different neurotransmitter systems in humans.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3838949 | PMC |
| http://dx.doi.org/10.1093/cercor/13.2.144 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Oncogenic IDH1 drives robust loss of histone acetylation and increases chromatin heterogeneity.
Proc Natl Acad Sci U S A
January 2025
Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
Malignant gliomas are heterogeneous tumors, mostly incurable, arising in the central nervous system (CNS) driven by genetic, epigenetic, and metabolic aberrations. Mutations in isocitrate dehydrogenase (IDH1/2) enzymes are predominantly found in low-grade gliomas and secondary high-grade gliomas, with IDH1 mutations being more prevalent. Mutant-IDH1/2 confers a gain-of-function activity that favors the conversion of a-ketoglutarate (α-KG) to the oncometabolite 2-hydroxyglutarate (2-HG), resulting in an aberrant hypermethylation phenotype.
View Article and Find Full Text PDFRetinal ganglion cells encode the direction of motion outside their classical receptive field.
Proc Natl Acad Sci U S A
January 2025
Department of Brain Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
Retinal ganglion cells (RGCs) typically respond to light stimulation over their spatially restricted receptive field. Using large-scale recordings in the mouse retina, we show that a subset of non- direction-selective (DS) RGCs exhibit asymmetric activity, selective to motion direction, in response to a stimulus crossing an area far beyond the classic receptive field. The extraclassical response arises via inputs from an asymmetric distal zone and is enhanced by desensitization mechanisms and an inherent DS component, creating a network of neurons responding to motion toward the optic disc.
View Article and Find Full Text PDFHydroxychloroquine prevents resistance and potentiates the antitumor effect of SHP2 inhibition in NF1-associated malignant peripheral nerve sheath tumors.
Proc Natl Acad Sci U S A
January 2025
Cancer Biology & Genetics Program, Sloan Kettering Institute, New York, NY 10065.
Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas and the primary cause of mortality in patients with neurofibromatosis type 1 (NF1). These malignancies develop within preexisting benign lesions called plexiform neurofibromas (PNs). PNs are solely driven by biallelic loss eliciting RAS pathway activation, and they respond favorably to MEK inhibitor therapy.
View Article and Find Full Text PDFOppositional and competitive instigation of hippocampal synaptic plasticity by the VTA and locus coeruleus.
Proc Natl Acad Sci U S A
January 2025
Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.
The novelty, saliency, and valency of ongoing experiences potently influence the firing rate of the ventral tegmental area (VTA) and the locus coeruleus (LC). Associative experience, in turn, is recorded into memory by means of hippocampal synaptic plasticity that is regulated by noradrenaline sourced from the LC, and dopamine, sourced from both the VTA and LC. Two persistent forms of synaptic plasticity, long-term potentiation (LTP), and long-term depression (LTD) support the encoding of different kinds of spatial experience.
View Article and Find Full Text PDFMicroRNA-204-5p Deficiency within the vmPFC Region Contributes to Neuroinflammation and Behavioral Disorders via the JAK2/STAT3 Signaling Pathway in Rats.
Adv Sci (Weinh)
January 2025
Key Laboratory of Mental Disorders, The Second Hospital of Shandong University, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, 250012, China.
Major depressive disorder (MDD) is usually considered associate with immune inflammation and synaptic injury within specific brain regions. However, the molecular mechanisms underlying the neural deterioration resulting in depression remain unclear. Here, it is found that miR-204-5p is markedly downregulated in the ventromedial prefrontal cortex (vmPFC) in a chronic unpredictable mild stress (CUMS) induce rat model of depression.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!