Electromyography and Fos immunostaining study establish a possible functional link between trigeminal proprioception and the oculomotor system in rats

The objective of this study was to explore whether there was a functional link between trigeminal proprioception and the oculomotor system mediated through jaw muscle afferents.Electromyography（EMG） was undertaken of the levator palpebrae（LP） and superior rectus（SR）,and Fos expression was detected in the brainstem following consecutive down-stretching of the lower jaw at 2-4 Hz in rats.Retrograde tracing was undertaken of the interstitial nucleus of Cajal and Darkschewitsch nucleus（INC/DN） pre-oculomotor neurons.FMG-like responses were recorded from the LP/SR during down-stretching of the lower jaw at 2-4 Hz in 3 out of 11 rats.Fos expression was induced by consecutive down-stretching of the lower jaw at 2-4 Hz for 20-30 seconds.Interestingly,Fos expression was distributed mainly in the bilateral INC/DN area.We also examined Fos-like immunoreactivity in central mesencephalic and paramedian pontine reticular formation that harbors premotor neurons controlling horizontal eye movement,but no Fos-like staining was observed therein.By injection of retrograde tracers into the oculomotor nucleus combined with Fos immunostaining,double labeled pre-oculomotor neurons were visualized to distribute in the INC/DN.In conclusions,there may exist a trigeminal proprioceptive-oculomotor system neural circuit through jaw muscle afferents in rats.Judging from Fos distribution pattern,this pathway might be related to vertical and torsional eye movements.

Effective electromagnetic shielding with multi-layer structure material on Shenguang laser facility

Electromagnetic pulses(EMPs)with high intensity and frequency bandwidth can be generated during the intensive laser irradiating solid targets in inertial confinement fusion(ICF).To shield the EMPs radiation and hence protect various diagnostics in and outside the target chamber,we designed a multi-layer structure material to shield the EMFs and demonstrate experimentally and numerically shielding performance of the material structure.The thickness of the multi-layer structure material has a great influence on the EMPs shielding.It is shown that,with the increase of the material thickness,the better shielding performance is obtained,and the material structure with polytetrafluoroethyIene of 0.5 mm,copper of 0.4 mm and lead of 2.4 mm reduces 448 times compared the maximum value of EMPs voltage to that without shielded.The design of multilayer structure material for EMPs shielding provides a promising way to reduce EMPs radiation,which is extremely useful for the diagnostics protection and signal processing in ICF.