AIM:To establish a rapid in vitro method for mast cell degranulation tracing by raster image corre-lation spectroscopy (RICS).METHODS:RBL-2H3, a basophilic granulocyte mast cell line transfected with CD 63-GFP plasmid, was used for evaluating the methods , including β-hexosaminidase ( HEX) colorimetric assay, scanning electron microscopy (SEM) and RICS in the detection of mast cell degranulation .The sensibilities of these methods were com-pared.RESULTS:The sensitivities of β-HEX colorimetric assay and SEM were 5 mg/L and 3.9 ×10 -2 mg/L, respec-tively.RICS detection showed obvious decrease in the diffusion coefficient at dose of 3.9 ×10 -2 mg/L.CONCLUSION:Fluorescent molecular diffusion dynamic measurement can be used for rapid tracing of allergic substances in vitro.Accord-ing to the results, RICS can achieve nearly the same extent of sensitivity as the SEM does and is far more sensitive than β-HEX colorimetric assay.Compared with SEM, RICS has several advantages: it is faster, simpler and cheaper; it can be used in living cells;it is more suitable for rapid in vitro allergenic compounds tracing .Therefore, RICS is applicable in clinic allergic antigen screening and may also be used in pharmaceutical quality control .

Isolation rearing (IR) enhances aggressive behavior, and the central serotonin (5-hydroxytryptamine, 5-HT) system has been linked to IR-induced aggression. However, whether the alteration of central serotonin is the cause or consequence of enhanced aggression is still unknown. In the present study, using mice deficient in central serotonin Tph2 and Lmx1b, we examined the association between central serotonin and aggression with or without social isolation. We demonstrated that central serotonergic neurons are critical for the enhanced aggression after IR. 5-HT depletion in wild-type mice increased aggression. On the other hand, application of 5-HT in Lmx1b mice inhibited the enhancement of aggression under social isolation conditions. Dopamine was downregulated in Lmx1b mice. Similar to 5-HT, L-DOPA decreased aggression in Lmx1b mice. Our results link the serotoninergic system directly to aggression and this may have clinical implications for aggression-related human conditions.