Neuroscience
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Transparency of C. elegans enables microscopic in vivo imaging of cellular processes, but immobilization is required due to high locomotor activity. Here, anesthetic-like effects of dissociate anesthetic ketamine in adult C. elegans are presented using video recordings and infrared-based automated activity tracking. Ketamine caused a reversible blockade of locomotion at a similar concentration (20-50 mM) at which conventionally used immobilizing agent sodium azide (NaN3) produces paralysis. ⋯ However, a marked chemosensation deficiency was noted immediately after 20 mM ketamine exposure. Short-term ketamine treatment did not show signs of SKN-1 (skinhead-1) activation, a marker of the stress response associated with NaN3. In sum, our results show ketamine's potential as a non-toxic nematode immobilizing agent and rationalize C. elegans as a model organism to understand its pharmacology.
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The temporal order of propagation in the blood-oxygen-level-dependent (BOLD) infra-slow activity (ISA, 0.01-0.1 Hz) of functional magnetic resonance imaging (fMRI) can indicate the functional organization of the brain. While prior studies have revealed the temporal order of propagation of BOLD ISA during rest, how it emerges during cognitive tasks remains unclear. Furthermore, its differences between the gray and white matters at the whole-brain scale are unexplored. ⋯ This result differs from the previously reported propagation direction during rest that traveled from the visual and somatosensory cortices to the DMN, suggesting that the functional organization may change when performing cognitive tasks. In addition, the propagation in the white matter represented more complex patterns than that in the gray matter, exhibiting that the cingulum preceded DMN. Our results may help the understanding of how task performance alters the sensory-DMN propagation according of ISA.
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Review
Advances in diagnostic imaging and interventional treatment of aphasia after basal ganglia stroke.
Post-stroke basal ganglia aphasia is an unusual and transient form of aphasia resulting from basal ganglia damage. It is commonly believed that the generation of language function primarily resides in regular language regions of the brain; however, recent findings indicate a prevalence of basal ganglia stroke aphasia as high as 22%. Subcortical structures (e.g., basal ganglia) also play an important role in language processing. ⋯ Treatment for post-stroke basal ganglia aphasia includes transcranial magnetic stimulation, a recent emerging therapeutic technique, in addition to conventional medications and speech rehabilitation. Consequently, understanding this condition is crucial. This review delves into its causes, imaging methods, and therapeutic interventions, offering a systematic and comprehensive analysis of these aspects.
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Face recognition is an important aspect of human non-verbal communication. Event-related potentials or magnetic fields, such as the N170/M170 component, are considered essential neural markers of face processing. Compared to upright human faces, inverted human faces and upright but not inverted animal faces cause longer latencies and larger amplitudes of these components. ⋯ Additionally, face orientation differentially modulated the anterior region of the fusiform gyrus (FG) in both face categories. These results suggest that spatiotemporal dynamics differ in face orientation regardless of category and that the FG contributes little or nothing to the M170 modulation recorded in the scalp sensor. Furthermore, we demonstrated that inverted human and animal faces are processed via different mechanisms.