Neuroscience
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Sex differences in brain and behavior exist across vertebrates, but the molecular factors regulating their development are largely unknown. Songbirds exhibit substantial sexual dimorphisms. In zebra finches, only males sing, and the brain areas regulating song learning and production are much larger in males. ⋯ The latter was also increased in males compared to females at post-hatching day 25. With double-label immunofluorescence and retrograde tract tracing, we also document that the majority of TBCA+ cells in LMAN are neurons, and that they include robust nucleus of the arcopallium-projecting cells. These results indicate that TBCA is both temporally and spatially primed to facilitate the development of a sexually dimorphic neural pathway critical for song.
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Randomized Controlled Trial
Finger-specific loss of independent control of movements in musicians with focal dystonia.
The loss of independent control of finger movements impairs the dexterous use of the hand. Focal hand dystonia is characterised by abnormal structural and functional changes at the cortical and subcortical regions responsible for individuated finger movements and by the loss of surround inhibition in the finger muscles. However, little is known about the pathophysiological impact of focal dystonia on the independent control of finger movements. ⋯ Interestingly, the movement features that contributed to successful classification differed across fingers. Compared to healthy pianists, pianists with an affected index finger were characterised predominantly by stronger keystrokes, whereas pianists with affected middle or ring fingers exhibited abnormal temporal control of the keystrokes, such as slowness and rhythmic inconsistency. The selective alternation of the movement features indicates a finger-specific loss of the independent control of finger movements in focal dystonia of musicians.
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Hyperbaric oxygen-induced seizures are classified as brief, generalized tonic-clonic seizures. They are believed to cause no residual cognitive damage, although this has not been investigated in depth. In the present study, we examined whether hyperbaric oxygen-induced seizures cause impairment of behavioral and cognitive abilities. ⋯ We conclude that hyperbaric oxygen-induced seizures result in transient impairment of performance on behavioral tests in a mouse model. Further investigation is required to establish the mechanism and location of injury, and to determine whether the performance decrement on the elevated plus maze test represents permanent damage or transient damage with slow resolution. These new findings should be taken into account when planning hyperbaric oxygen treatments, to ensure that the chosen protocol is therapeutic yet minimizes the risk of CNS oxygen toxicity.
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Accumulating evidence indicates that activation of spinal cord astrocytes contributes importantly to nerve injury and inflammation-induced persistent pain and chronic opioid-induced antinociceptive tolerance. Phosphorylation of extracellular signal-regulated kinase (pERK) and induction of interleukin-1 beta (IL-1β) in spinal astrocytes have been implicated in astrocytes-mediated pain. Tissue plasminogen activator (tPA) is a serine protease that has been extensively used to treat stroke. ⋯ Intrathecal injection of tPA results in up-regulation of GFAP and pERK in spinal astrocytes but not up-regulation of ionized calcium binding adapter molecule 1 in spinal microglia. Finally, intrathecal tPA elicits persistent mechanical allodynia, which is inhibited by the astroglial toxin alpha-amino adipate and the MEK (ERK kinase) inhibitor U0126. Collectively, these data suggest an important role of tPA in regulating astrocytic signaling, pain hypersensitivity, and morphine tolerance.
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The Kavli Prize in Neuroscience was awarded for the third time in September 2012, by the Norwegian Academy of Science and Letters in Oslo. The accompanying Kavli Prize Symposium on Neuroscience, held in Bergen and Trondheim, was a showcase of excellence in neuroscience research. The common theme of the Symposium presentations was the mechanisms by which animals adapt to their environment. ⋯ Innate behaviors can be stably transmitted from parent to offspring through generations even when those behaviors cannot be expressed, as illustrated by the elaborate burrowing behavior in a rodent species, in which independent genetic regions regulate distinct modules of the burrowing pattern (Hoekstra). Finally, at the other extreme of the nature-nurture scale, functional magnetic resonance imaging (fMRI) analysis in children and adults identified a brain area specifically involved in reading (Dehaene). As the area must originally have developed for a purpose other than reading, such as shape recognition, this illustrates the use of a previously formed neural structure to tackle a new challenge.