Allocentric and egocentric spatial representations coexist in rodent medial entorhinal cortex.

Successful navigation relies on reciprocal transformations between spatial representations in world-centered (allocentric) and self-centered (egocentric) frames of reference. The neural basis of allocentric spatial representations has been extensively investigated with grid, border, and head-direction cells in the medial entorhinal cortex (MEC) forming key components of a 'cognitive map'. Recently, egocentric spatial representations have also been identified in several brain regions, but evidence for the coexistence of neurons encoding spatial variables in each reference frame within MEC is so far lacking.

Intrinsic Bipolar Head-Direction Cells in the Medial Entorhinal Cortex.

Head-direction (HD) cells are a fundamental component in the hippocampal-entorhinal circuit for spatial navigation and help maintain an internal sense of direction to anchor the orientation in space. A classical HD cell robustly increases its firing rate when the head is oriented toward a specific direction, with each cell tuned to only one direction. Although unidirectional HD cells are reported broadly across multiple brain regions, computation modelling has predicted the existence of multiple equilibrium states of HD network, which has yet to be proven.

Border cells without theta rhythmicity in the medial prefrontal cortex.

The medial prefrontal cortex (mPFC) is a key brain structure for higher cognitive functions such as decision-making and goal-directed behavior, many of which require awareness of spatial variables including one's current position within the surrounding environment. Although previous studies have reported spatially tuned activities in mPFC during memory-related trajectory, the spatial tuning of mPFC network during freely foraging behavior remains elusive. Here, we reveal geometric border or border-proximal representations from the neural activity of mPFC ensembles during naturally exploring behavior, with both allocentric and egocentric boundary responses.

Magnesium-induced preparation of boron nitride nanotubes and their application in thermal interface materials.

The effective growth of boron nitride nanotubes (BNNTs) by boron oxide chemical vapor deposition (BOCVD) is extremely challenging, especially in a horizontal tube furnace. Herein, we propose a novel Mg-induction strategy, which is low cost and efficiently generates BNNTs by separating Mg from diverse boron sources (B2O3, H3BO3, borates, and so on). After careful analysis and discussion of the prepared BNNTs, the corresponding in situ generation of MgB2, an effective catalyst for the growth of BNNTs, was proposed and verified.

Growth of boron nitride nanotubes from magnesium diboride catalysts.

The difficulty in synthesizing boron nitride nanotubes (BNNTs) in a conventional horizontal tube furnace by chemical vapor deposition (CVD) may be ascribed to the failure to identify suitable catalysts and nucleation particles. This report demonstrates that magnesium diboride (MgB) can effectively catalyze the growth of BNNTs in such a tube furnace from various boron sources, including boron oxide (BO), boric acid (HBO), and a mixture of boron (B) and calcium oxide (CaO). This catalyst is more efficient than the possible magnesium oxide (MgO) or magnesium nitride (MgN) catalysts.

In Situ Generation of Photosensitive Silver Halide for Improving the Conductivity of Electrically Conductive Adhesives.

Electrically conductive adhesives (ECAs) can be regarded as one of the most promising materials to replace tin/lead solder. However, relatively low conductivity seriously restricts their applications. In the present study, we develop an effective method to decrease the bulk electrical resistivity of ECAs.

Bimetallic catalytic growth of boron nitride nanotubes.

Boron nitride nanotubes (BNNTs) have outstanding properties and potential applications. However, the fundamental issue regarding the growth mechanism remains an open question. Herein, we design a bimetallic catalyst that dissolves B and N simultaneously, which has been proved to be key for BNNT growth.

Freestanding Boron Nitride Nanosheet Films for Ultrafast Oil/Water Separation.

Freestanding boron nitride nanosheet (BNNS) films with designed structures are first fabricated by chemical vapor deposition (CVD) methods. As-prepared freestanding BNNS films exhibit outstanding hydrophobicity and lipophilicity properties. Such brilliant behaviors make them applicable in oil/water separation with very high fluxes up to 1 200 000 L m h bar and excellent separation efficiencies (ppm level in terms of the water content in the filtrate).

Median nerve stimulation reduces ventricular arrhythmias induced by dorsomedial hypothalamic stimulation.

Background: This study tested the hypothesis that median nerve stimulation (MNS) prevents ventricular arrhythmias (VAs) induced by dorsomedial hypothalamus stimulation (DMHS) and investigated the electrophysiological mechanisms underlying the anti-arrhythmic effects of MNS by recording left stellate ganglion activity (LSGA).

Methods: Eighteen rabbits were anesthetized, the median nerve was anchored by stimulating electrodes, and a bipolar electrode was implanted into the LSG to record nerve activity. The DMH was stimulated to induce arrhythmia.

Magnetogenetics: remote non-invasive magnetic activation of neuronal activity with a magnetoreceptor.

Current neuromodulation techniques such as optogenetics and deep-brain stimulation are transforming basic and translational neuroscience. These two neuromodulation approaches are, however, invasive since surgical implantation of an optical fiber or wire electrode is required. Here, we have invented a non-invasive magnetogenetics that combines the genetic targeting of a magnetoreceptor with remote magnetic stimulation.