Neuroscience
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Few researchers have investigated the direction of commissural axon projections on the contralateral side of the vertebrate embryonic spinal cord, especially for comparison between its different regions. In this study, pCAGGS-GFP plasmid expression was limited to different regions of the chicken embryonic spinal cord (cervical, anterior limb, anterior thorax, posterior thorax and posterior limb) at E3 using in ovo electroporation with modified electrodes and optimal electroporation conditions. Then open-book technique was performed at E6 to analyze the direction of axon projections in different spinal cord regions. ⋯ The ratio of rostral and caudal projections was significantly different between the five investigated regions (P<0.05), except between the cervical region and the anterior limb (P>0.05). The projections were most likely to be rostral for the posterior limb followed by the posterior thorax, cervical region, anterior limb and anterior thorax. Our data for the direction of the commissural axon projections will be helpful in the future analyses of axon projection mechanisms and spinal cord-brain circuit formation.
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Previous studies have shown that Event-related potentials (ERPs) are sensitive to violations of gender-based stereotypes. In the present investigation, we used ERPs to measure the detection of a discrepancy between gender-based occupational stereotypes and written material presented to fifteen Italian viewers in a completely implicit task. No awareness or judgment about stereotypes was required, no decision had to be made on sentence acceptability or congruence, and no prime words related to gender were presented (which might reveal the matter of the investigation). ⋯ LAN modulation suggests that gender stereotypes are processed automatically (as if they were morpho-syntactic errors) and hints at how they are deeply rooted in our linguistic brain. According to the inverse solution, the neural representation of gender-based stereotypes mostly involved the middle frontal gyrus (MFG). The temporo/parietal junction (TPJ) supporting theory of mind (TOM) processes was also engaged, along with the superior and middle temporal gyri representing person information.
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Numerous experimental and clinical studies have suggested that the interaction between the immune system and the brain plays an important role in the pathophysiology of chronic fatigue syndrome (CFS). The NLRP3 inflammasome is an important part of the innate immune system. This complex regulates proinflammatory cytokine interleukin-1β (IL-1β) maturation, which triggers different kinds of immune-inflammatory reactions. ⋯ The NLRP3 KO mice displayed significantly moderated fatigue behaviors along with decreased PFC and serum IL-1β levels under the same treatment. These findings demonstrated the involvement of NLRP3 inflammasome activation in the mechanism of swimming-induced fatigue. Future therapies targeting the NLRP3/IL-1β pathway may have significant potential for fatigue prevention and treatment.
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Cholecystokinin (CCK)-expressing neurons within the nucleus of the solitary tract (CCKNTS) of the mouse are responsive to satiety signals and their chemogenetic activation suppresses appetite. Optogenetic activation of CCKNTS axon terminals within either the parabrachial nucleus (PBN) or the paraventricular nucleus of the hypothalamus (PVH) is sufficient to suppress feeding. ⋯ Activation of the CCKNTS→PBN pathway is also aversive; however, stimulating the CCKNTS→PVH pathway is appetitive when assayed using a real-time, place-preference task. Thus, these two projections from CCKNTS neurons reduce food intake through opposite motivational states; one pathway signals positive valence (CCKNTS→PVH) and the other signals negative valence (CCKNTS→PBN).
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The NMDA receptor (NMDAr) hypofunction theory of schizophrenia suggests that aberrant signaling through NMDAr underlies the pathophysiology of this disease. This is commonly modeled in rodents via treatment with NMDAr antagonists, which causes a range of behavioral effects that represent endophenotypes related to schizophrenia. These drugs also disrupt high-frequency neural oscillations within the brain, also potentially relevant to disease. ⋯ Regardless of MK801 infusion location, gamma oscillations and HFOs significantly and consistently increased in all three regions studied, similar to that observed following systemic injection. Locomotor activity, stereotypies and ataxia were also observed following infusion into all regions. We conclude that localized regions exhibiting NMDAr hypofunction are sufficient to disrupt local as well as diffuse neural circuits and global brain function, and concomitantly cause psychosis-related behavioral effects.