Neuroscience
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Tinnitus is a bothersome phantom sound percept and its neural correlates are not yet disentangled. Previously published papers, using [(18)F]-fluoro-deoxyglucose positron emission tomography (FDG-PET), have suggested an increased metabolism in the left primary auditory cortex in tinnitus patients. This unilateral hyperactivity has been used as a target in localized treatments such as transcranial magnetic stimulation. ⋯ Nevertheless, the activity in the left primary auditory cortex was higher than in the right primary auditory cortex, but this asymmetry was present in both tinnitus patients and control subjects. In contrast, the lateralization in secondary auditory cortex was opposite, with higher activation in the right hemisphere. These data show that hemisphere asymmetries in the metabolic resting activity of the auditory cortex are present, but these are not associated with tinnitus and are a normal characteristic of the normal brain.
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In this study we were interested in the neural system supporting the audiovisual (AV) integration of emotional expression and emotional prosody. To this end normal participants were exposed to short videos of a computer-animated face voicing emotionally positive or negative words with the appropriate prosody. Facial expression of the face was either neutral or emotionally appropriate. ⋯ In trials showing emotional expressions compared to neutral trials univariate analysis showed activation primarily in bilateral amygdala, fusiform gyrus, middle temporal gyrus/superior temporal sulcus and inferior occipital gyrus. When employing either the left amygdala or the right amygdala as a seed region in RFX-GCM we found connectivity with the right hemispheric fusiform gyrus, with the indication that the fusiform gyrus sends information to the Amygdala. These results led to a working model for face perception in general and for AV-affective integration in particular which is an elaborated adaptation of existing models.
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MicroRNA (miRNA) is a small non-coding RNA that regulates gene expression by degrading target mRNAs or inhibiting translation. Although many miRNAs play important roles in various conditions, it is unclear whether miRNAs are involved in motor nerve regeneration. ⋯ Furthermore, the luciferase assay and in vitro gain of function methods supported that both genes could be potent targets of miR-124. These results suggest that injury-induced repression of miR-124 may be implicated in the regulation of expression of several injury-associated transcription factors, which are crucial for appropriate nerve regeneration.
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α-Synuclein is the major component of Lewy bodies. α-Synuclein phosphorylated at Ser 129 (Phospho-α-Syn) is the most common synuclein modification observed in Parkinson's disease pathology and transgenic animal models. Polo-like kinase 2 (PLK2) was previously proposed as an important kinase in α-synuclein phosphorylation at Ser129. To better understand the role of PLK2 in α-synuclein phosphorylation in vivo, we further evaluated the effect of PLK2 genetic knockdown and pharmacological inhibition on Phospho-α-Syn levels in different brain regions of PLK2 knockout (KO), heterozygous (Het) and wild-type (WT) mice. ⋯ Whereas BI 2536 reduced Phospho-α-Syn levels in WT mice, it did not further reduce the residual endogenous Phospho-α-Syn levels in PLK2 KO and Het mice, suggesting that a kinase other than PLK1-3 accounts for the remaining PLK inhibitor-resistant pool in the mouse brain. Moreover, PLK3 KO in mice had no effect on both Total- and Phospho-α-Syn brain levels. These results support a significant role for a PLK kinase in phosphorylating α-synuclein at Ser129 in the brain, and suggest that PLK2 is responsible for this activity under physiological conditions.
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Verbal insight problem solving means to break mental sets, to select the novel semantic information and to form novel, task-related associations. Although previous studies have identified the brain regions associated with these key processes, the interaction among these regions during insight is still unclear. ⋯ Compared with noninsight solution, insight solution had a stronger functional connectivity between the inferior frontal gyrus and middle temporal gyrus in the right hemisphere. Our study reveals the neural pathway of information processing during verbal insight problem solving, and supports the right-hemisphere advantage theory of insight.