The development of Schwann cells, which myelinate axons in the peripheral nervous system, is critically dependent on MEK/ERK signaling. While Ets-domain transcription factors ( Etv1 , Etv4 , Etv5 ) are downstream effectors of this pathway, only Etv1 has been specifically linked to Schwann cell development. Here, we examined the functions of Etv5 , which is expressed in Schwann cell precursors, neural crest cells and satellite glia, at embryonic stages and at low levels in mature Schwann cells. In hypomorphic Etv5tm1Kmm homozygous mutant mice, no overt defects in Schwann cell differentiation were observed at embryonic stages. To study the function of Etv5 in juvenile (postnatal days 21–30) and mature adult (6 month) mice, we generated Etv5 conditional knock-outs (cKOs) using a Sox10-Cre driver. In juvenile male Etv5 -cKO mice, Schwann cell numbers increased normally after a peripheral nerve crush injury, a response that was attenuated by 6 months. Transmission electron microscopy of the naive sciatic nerve ...

The development of motor control over sensory organs is a critical milestone, enabling active exploration and shaping of the sensory environment. Whether the onset of sensory organ motor control directly influences the development of corresponding sensory cortices remains unknown. Here, we confirm and exploit the late onset of whisking behavior in mice to address this question in the somatosensory system. Using ex vivo electrophysiology, we describe a transient increase in the intrinsic excitability of excitatory neurons in layer IV of the barrel cortex, which processes whisker input, immediately following the onset of active whisking on postnatal days 13 and 14. This increase in neuronal gain is specific to layer IV, independent of changes in synaptic strength, and requires prior sensory experience. Further, these effects are not expressed in inhibitory interneurons in barrel cortex. The transient increase in excitability is not evident in layer II/III of barrel cortex or in the visual cortex upon eye ope...

When you navigate your home, you do so with certainty that when you open your bedroom door, you will enter your bedroom. Underlying this knowledge are top down predictions driven by learning, experience and familiarity. Visual cognition relies heavily o...

Lipopolysaccharide (LPS) is a bacterial endotoxin that induces innate immune responses. The present study aimed to elucidate alterations in cerebral cortical surface morphology induced by neonatal exposure to LPS using gyrencephalic ferrets. Male ferret pups received a subcutaneous injection of LPS (500 µg/g of body weight) on Postnatal Day (P)6 and P7. Furthermore, EdU and BrdU were administered on P5 and P7, respectively, to label postproliferative and proliferating cells that were exposed to LPS in the late stage of cortical neurogenesis. On P20 when the primary sulci and gyri had formed, MRI-based morphometry revealed an anterior shift in sulcal infolding in the medial and dorsolateral cortices of LPS-exposed ferrets. Immunofluorescence analysis showed that LPS increased the density of BrdU-labeled cells and reduced their apoptosis, as indicated by cleaved caspase-3 (cCasp3) immunostaining, in the outer stratum of the lateral sulcus located on the parietal association cortex. Furthermore, cCasp3 immuno...

Functional neuroimaging studies have repeatedly demonstrated widespread neural activation in response to adminstration of noxious stimuli. Many of these brain regions, such as prefrontal cortex and cerebellum, are not part of the presumed functional anatomy of pain perception. In this study we designed an experimental paradigm to test the hypothesis that some brain regions are activated during pain administration because they support the cognitive processes involved in the evaluation of the painful stimulus. To date six subjects have completed this 3T fMRI event-related imaging study that is approved by the MGH IRB. The data has been analyzed with SPM 2B using a random effects model. Preliminary analysis of the first half of the planned cohort has been performed and the results confirm our hypothesis. Using the contrast between stimulus trials that required subjects to rate the intensity of the stimulus as compared to trials in which they performed a matched target detection task, significantly increased B...

The Society for Neuroscience is seeking a new editor-in-chief for BrainFacts.org.

X-linked Dystonia-Parkinsonism (XDP) is an inherited, X-linked, adult-onset movement disorder characterized by degeneration in the neostriatum. No therapeutics alter disease progression. The mechanisms underlying regional differences in degeneration and adult onset are unknown. Developing therapeutics requires a deeper understanding of how XDP-relevant features vary in health and disease. XDP is possibly due, in part, to a partial loss of TAF1 function. A disease-specific SINE-VNTR-Alu (SVA) retrotransposon insertion occurs within intron 32 of TAF1 , a subunit of TFIID involved in transcription initiation. While all XDP males are usually clinically affected, females are heterozygous carriers generally not manifesting the full syndrome. As a resource for disease modeling, we characterized eight iPSC lines from three XDP female carrier individuals for X chromosome inactivation status and identified clonal lines that express either the wild-type X or XDP haplotype. Furthermore, we characterized XDP-relevant t...

Not every graduate student will follow the footsteps of their mentor and become a professor in academia.

The prepositus hypoglossi nucleus (PHN), involved in horizontal gaze control, contributes to this function via cooperation with the vestibulocerebellum (VC). Furthermore, some PHN neurons have also been observed to project to cerebellar regions outside the VC. We previously reported a neuronal population in the ventral caudal PHN that projects to lobules III–V of the anterior vermis or to the cerebellar hemispheric crus. Because the properties of these neurons have not been clarified, this study aimed to determine their localization, projections, and electrophysiological and morphological characteristics in male rats. Tracing experiments revealed that these neurons were clustered within the ventral caudal PHN, approximately between bregma -12.72 mm and -12.00 mm, and did not project to the uvula/nodulus (UN), which is part of the VC. Whole-cell recordings and morphological experiments revealed that these PHN neurons exhibited high input capacitance, low input resistance, low-frequency firing, prominent vol...

There is a growing imperative to understand the neurophysiological impact of our rapidly changing and diverse technological, social, chemical, and physical environments. To untangle the multidimensional and interacting effects requires data at scale across diverse populations, taking measurement out of a controlled lab environment and into the field. Electroencephalography (EEG), which has correlates with various environmental factors as well as cognitive and mental health outcomes, has the advantage of both portability and cost-effectiveness for this purpose. However, with numerous field researchers spread across diverse locations, data quality issues and researcher idle time due to insufficient participants can quickly become unmanageable and expensive problems. In programs we have established in India and Tanzania, we demonstrate that with appropriate training, structured teams, and daily automated analysis and feedback on data quality, nonspecialists can reliably collect EEG data alongside various surv...