Pathological pain or clinical pain is caused by tissue and nerve injuries,and is usually chronic and mainly divided into inflammatory pain and neuropathic pain. Pathological pain is typically characterized by hyperalgesia (increased responsiveness to noxious stimuli) and allodynia (painful responses to normally innocuous stimuli). The MAPKs are a family of evolutionally conserved molecules that play a critical role in cell signaling,consisting of extracellular signal-regulated kinase (ERK),p38,and c-Jun N-terminal kinase (JNK),which play an important role in neural plasticity of pathological pain. Inhibition of MAPKs alleviates inflammatory pain and neuropathic pain in different animal models. It is very important to study the inhibition of MAPKs as a therapeutic approach to treating pathological pain. All the studies suggest that MAPKs is a promising therapeutic target for pathological pain.

Objective To compare the differences of laboratory rodents endolymphatic sac (ES) in histology , and to provide an anatomic basis for the clinical research of ES -related diseases .Methods The temporal bones of guinea pigs ,SD rats and KM mice were fixed by heart perfusion ,sectioned by paraffin at the horizontal position and stained by hematoxylin -eosin (HE) .Results All 3 rodents ES contained sac ,epithelium ,sub-mucosal tissue and saccal stroma .The cells were bulky ,stained deep and protruded into the cavity to form a large number of nipples and wrinkles in the middle ES epithelial of guinea pigs .But the nipples or wrinkles was rarely observed in the middle ES epithelial in rat and mouse .Conclusion The histology of ES has significant difference among guinea pig ,mouse and rat .While the difference betweeen mouse and rat is not obvious .

Objective To study the distribution and properly of the transparent globules within Hensen cells (HC) of guinea -pig Corti organ .Methods The cochlear epithelial cells were isolated from 10 guinea pigs .The cells of cochlea were marked by Bodipy493/503 ,sudan III ,oil red O ,and osmium tetroxide .Results The transpar‐ent globules within the HCs of the guinea -pigs were green staining by Bodipy493/503 ,jacinth staining by Sudan III ,ruby red by oil red O .And they were black globules stripe as post -fixed in 1% osmium tetroxide .Conclusion The results indicate that the transparent globules within guinea -pigs HCs'lipid droplets by four methods .