The Journal of neuroscience : the official journal of the Society for Neuroscience
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Randomized Controlled Trial
Stimulation of Dorsolateral Prefrontal Cortex Enhances Adaptive Cognitive Control: A High-Definition Transcranial Direct Current Stimulation Study.
Conflict adaptation is a hallmark effect of adaptive cognitive control and refers to the adjustment of control to the level of previously experienced conflict. Conflict monitoring theory assumes that the dorsolateral prefrontal cortex (DLPFC) is causally involved in this adjustment. However, to date, evidence in humans is predominantly correlational, and heterogeneous with respect to the lateralization of control in the DLPFC. ⋯ In contrast, active stimulation had no effect on conflict adaptation in the M1 groups. In sum, the present results indicate that the DLPFC plays a causal role in adaptive cognitive control, but that the involvement of DLPFC in control is not restricted to the left or right hemisphere. Moreover, our study confirms the potential of HD-tDCS to modulate cognition in a regionally specific manner.
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Calcium homeostasis plays a major role in maintaining neuronal function under physiological conditions. Amyloid-β (Aβ) initiates pathological processes that include disruption in intracellular calcium levels, so amelioration of the calcium alteration could serve as an indirect functional indicator of treatment efficacy. Therefore, calcium dynamics were used as a measure of functional outcome. ⋯ Although chronic systemic administration of aducanumab in 22-month-old mice did not clear existing plaques, calcium overload was ameliorated over time. Therefore, this antibody likely restores neuronal network function that possibly underlies cognitive deficits, indicating promise as a clinical treatment. In addition, functional readouts such as calcium overload may be a more useful outcome measure to monitor treatment efficacy in models of Alzheimer's disease compared with amyloid burden alone.
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Working memory, the ability to temporarily maintain representational knowledge, is a foundational cognitive process that can become compromised in aging and neuropsychiatric disease. NMDA receptor (NMDAR) activation in prefrontal cortex (PFC) is necessary for the pyramidal neuron activity believed to enable working memory; however, the distinct biophysical properties and localization of NMDARs containing NR2A and NR2B subunits suggest unique roles for NMDAR subtypes in PFC neural activity and working memory. ⋯ Finally, NMDAR currents and working memory are enhanced in aged rats by promoting activation of the NR2A-enriched synaptic pool of PFC NMDARs. These results implicate NR2A-NMDARs in normal working memory and suggest novel treatment strategies for improving working memory in cognitive disorders.