Objective To study the change of frequency tuning in inferior collicular neurons when added weak noise forward masking.Methods We examined the changes in neuronal frequency tuning resulted from a weak white noise as forward masking relative to 5dB beyond minimum threshold (reMT+5) and different duration (40、60、80、100 ms) under free field stimulation conditions.Results Weak noise forward masking sharpens frequency tuning curves (FTCs) of most neurons (P

OBJECTIVE Based on different drug loading models,three types of nanoparticulated HI-6 were prepared and their reactivations on inhibited acetylcholinesterase (AChE)in peripheral and central nervous syste ms were evaluated and compared in so man-intoxicated mice.METHODS Three kinds of nano-reactivators including HI-6 loaded human serum albunin nanoparticle (HSA-HI-6 NP),HI-6 absorptive mesoporous silica nanoparticle(MSN-HI-6),polylactico-glycolic acid nanoparticle coated HI-6 (PLGA-HI-6 NP)were prepared.The characteristic of all blank nanocarriers was observed through elec-tron microscope.HI-6 release rate of nano-reactivators was also determined in vitro.Then the reactiva-tion rate of nano-reactivators at a constant HI-6 dosage(22 mg·kg -1 )on so man-inhabited AChE both in blood and brain was assessed the so man intoxicated mice(120 μg·kg -1 ,sc).RESULTS All the syn-thetic nanocarriers met the de mand for nanodrug use in vivo.The rate of HI-6 release of nano-reactiva-tors was HI-6 >HSA-HI-6 NPs >MSN-HI-6 >PLGA-HI-6 NP in vitro.On the reactivations of so man-inhibited mice blood AChE,the free HI-6 and HSA-HI-6 NPs,as well as MSN-HI-6 showed co mparable reactivation rates(20% -30%)but were greater than that of PLGA-HI-6 NPs (6.2%)(P <0.01 ). However on the reactivations of so man-inhibited mice brain AChE,the reactivation rate of HSA-HI-6 NP (15.3%)was significantly higher than that of PLGA-HI-6 NP(3.3%)and free HI-6(6.3)(P<0.01 ).In addition,MSN-HI-6 group had a significant reactivation rate compared to PLGA-HI-6 NPs(P <0.01 ). But there was no statistic difference between MSN-HI-6 and free HI-6.CONCLUSION The reactivation potency changed obviously with different drug loading models and HSA-HI-6 NPs had the most potent reactivation on so man-inhibited AChE in both blood and brain.