Neuroscience
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Perceptual decisions, especially for difficult stimuli, can be influenced by choices and outcomes in previous trials. However, it is not well understood how stimulus strength modulates the temporal characteristics as well as the magnitude of trial history influence. We addressed this question using a contrast detection task in freely moving mice. ⋯ We found that more M2 neurons conveyed information about choices on the past two trials at lower than at higher contrast. Furthermore, history-trial activity in M2 was important for decoding upcoming choice at low contrast. Thus, trial history influence of perceptual choice is adaptive to the strength of sensory evidence, which may be important for action selection in a dynamic environment.
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Inflammation aggravates the lethal consequences of intracerebral hemorrhage. Recently, many studies have found that nuclear factor-κB (NF-κB) is a crucial transcription factor that initiates inflammation in the perihematomal region of ICH. NF-κB essential modulator (NEMO)-binding domain (NBD) peptide, a cell-permeable peptide spanning the NBD of IKKα or IKKβ, functions as a highly specific inhibitor of NF-κB. ⋯ We found that NBD peptides suppressed microglia inflammation and lowered the expression of TNF-α and IL-1β in both in vivo and in vitro experiments. Further experiments were performed in mice and cultured microglia, which treated with NBD peptides in the presence of p65 siRNA confirmed that the specificity of NBD peptides inhibit ICH-induced NF-κB activation. This study demonstrated that NBD peptides exert a neuroprotective role after ICH and might be a potential candidate for a novel therapeutic strategy for ICH.
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Fatty acid binding protein 7 (FABP7) is expressed in astrocytes of the developing and mature central nervous system, and modulates astrocyte function by controlling intracellular fatty acid homeostasis. Astrocytes in the spinal cord have an important role in the process of myelin degeneration and regeneration. In the present study, the authors examined the role of FABP7 in astrocytes in a mouse model of experimental autoimmune encephalomyelitis (EAE), which is an established model of multiple sclerosis (MS). ⋯ Moreover, the area exhibiting expression of fibronectin, which is an extracellular matrix protein mainly produced by astrocytes and inhibits remyelination of oligodendrocytes, was significantly decreased in FABP7-KO compared with WT mice. Collectively, FABP7 in astrocyte may have a role to protect from the induction of inflammation leading to demyelination in CNS at early phase of EAE. Moreover, FABP7 may be involved in the regulation of fibronectin production through the modification of astrocyte activation at late phase of EAE.
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Parkinson's disease (PD) is the most common neurodegenerative movement disorder and is characterized by the loss of neurons in the substantia nigra that project to the striatum and release dopamine (DA), which is required for normal movement. Common non-motor symptoms likely involve abnormalities with other neurotransmitters, such as serotonin, norepinephrine, acetylcholine, glycine, glutamate and gamma-aminobutyric acid (GABA). As part of a broad effort to provide better PD research tools, the Michael J. ⋯ Parkin KO rats had increased glycine release while DJ-1 KO rats had decreased glutamate release and increased acetylcholine release compared to WT rats. All lines except DJ-1 KO rats showed age-dependent changes in release of one or more neurotransmitters. Our data suggest these rats may be useful for studies of PD-related synaptic dysfunction and neurotransmitter dynamics as well as studies of the normal and pathogenic functions of these genes with PD-linked mutations.
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Review
New Perspectives for the Modulation of Mind-Wandering Using Transcranial Electric Brain Stimulation.
When our attention is decoupled from an ongoing task and becomes coupled to thoughts and feelings not being subject to task engagement, we are mind-wandering. This transient and pervasive mental process can occupy a considerable amount of our waking hours. Mind-wandering is understood to exert both positive and negative effects on well-being, and has been shown to play a role in mood disorders and depression. ⋯ For instance, tDCS effects on deliberate versus undeliberate mind-wandering should be disentangled. The hippocampus as an important hub for mind-wandering-related processes may be targeted. Most importantly, research efforts related to mind-wandering and rumination should be integrated.