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...

Read advocacy news from the week of November 4, 2016.

Discounted registration is now open for Institutional Program (IP) members.

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...

Read advocacy news from the week of October 14, 2016.

It has long been hypothesized that the nervous system uses the direction of gravity to align the various sensory systems when interacting with the external world. In line with this hypothesis, systematic drift in hand-path orientation was recently observed during targeted arm motions performed with eyes closed in weightlessness or, on Earth, for longitudinal movements in a supine posture. No such drift was observed in upright posture on Earth. But the precise conditions under which participants exhibit such drift, and the factors that influence the magnitude of the drift, are not yet known. The objective of our study was to investigate if the upright posture, by virtue of being at a biomechanical singularity induced by the force of gravity, represents a unique condition in which drift in hand-path orientation is prevented. Human participants (male and female) performed sequences of repeated point-to-point arm movements between two visual targets aligned with the longitudinal body axis, first with eyes open...

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...

Recent fMRI studies reported transformed representations between perception and visual working memory (VWM) in the human early visual cortex (EVC). This is inconsistent with the still widely cited original proposal of the sensory account of VWM, which argues for a shared perception-VWM representation based on successful cross-decoding of the two representations. Although cross-decoding was usually lower than within-VWM decoding and consistent with transformed VWM representations, this has been attributed to experimental differences between perceptual and VWM tasks: once they are equated, the same representation is expected to exist in both. Including human participants of both sexes, this study compared target and distractor representations during the same VWM delay period for the same objects, thereby equating experimental differences. Even with strong VWM representations present throughout the occipitotemporal cortex (OTC, including EVC) and posterior parietal cortex (PPC), fMRI cross-decoding revealed s...

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

Principal neurons (PNs) of the lateral superior olive (LSO) are a critical component of brain circuits that compare information between the two ears to extract sound source-location-related cues. LSO PNs are not a homogenous group but differ in their transmitter type, intrinsic membrane properties, and projection pattern to higher processing centers in the inferior colliculus. Glycinergic inhibitory LSO PNs have higher input resistance than glutamatergic excitatory LSO PNs (∼double). This suggests that the inhibitory cell type has a lower minimum input or signal intensity required to produce an output (activation threshold) which may impact how they integrate binaural inputs. However, cell-type-specific differences in the strength of synaptic drive could offset or accentuate such differences in intrinsic excitability and have not been assessed. To evaluate this possibility, we used a knock-in mouse model to examine spontaneous and electrically stimulated (evoked) synaptic events in LSO PN types using volta...