[Characteristics of Soil Organic Carbon Components and Their Correlation with Other Soil Physical and Chemical Factors in Cotton Fields with Different Continuous Cropping Years in the Oasis on the Northern Edge of Tarim Basin].

The study of soil organic carbon components in continuous cropping cotton fields in oases is helpful to reveal the change characteristics of the soil organic carbon stability mechanism in arid areas under the effects of man-land relationships. In this study, the contents of soil organic carbon, easily oxidized organic carbon, dissolved organic carbon, and microbial biomass carbon in cotton fields with different continuous cropping years (2 a, 5 a, 12 a, 20 a, and 35 a) were collected and analyzed by using space instead of the time series method. Through redundancy analysis, the relationship between soil organic carbon components and other soil physical and chemical factors was discussed. The results showed that:① continuous cropping for different years had a significant impact on the content of soil organic carbon components in the study area. The contents of soil organic carbon, easily oxidized organic carbon, dissolved organic carbon, and microbial biomass carbon in continuous cropping cotton fields for 12 a, 20 a, and 35 a were higher than those in continuous cropping cotton fields and wasteland for 2 a and 5 a. ω(soil organic carbon) reached the peak value (7.06 g·kg-1) in the cotton field in 20 a, which was 76.91% higher than that in the wasteland. The content of soil organic carbon decreased with the deepening of the soil layer. ② Based on the redundancy analysis of soil organic carbon content and soil environmental factors, the results showed that the content of soil organic carbon was positively correlated with total nitrogen, available phosphorus, and water content and negatively correlated with pH value and bulk density. The importance of soil environmental factors on the interpretation of soil organic carbon content was as follows:total N>available P>pH value>bulk density>water content>available K>total salt.

Activation of Parvalbumin Neurons in the Rostro-Dorsal Sector of the Thalamic Reticular Nucleus Promotes Sensitivity to Pain in Mice.

The calcium-binding protein, parvalbumin (PV), is highly expressed in thalamic reticular nucleus (TRN) GABAergic neurons, which receive input from the cerebral cortex and thalamus and send inhibitory output to the thalamic relay nucleus. Previous studies suggest that the TRN is involved in pain regulation as an important relay nucleus of the ascending pain pathway. However, little is known about its functional role in pain regulation and interconnectivity. In our study, the role of rostro-dorsal sector of TRN (TRNrd) PV-positive neurons in pain regulation was studied using chemogenetics based on designer receptors exclusively activated by designer drugs (DREADD). Then, projections from the TRNrd PV-positive neurons were explored using PV-Cre transgenic mice, conditional anterograde axonal tract tracing, and optogenetics, combined with immunohistochemistry and electrophysiology. The results showed that activation of PV-positive neurons in the TRNrd decreased the mechanical threshold and thermal latency of behaving mice during the light period when neuronal activity was low. Furthermore, the anterodorsal and paratenial thalamic nucleus received innervation from PV-positive neurons in the TRNrd. They were specifically inhibited by GABA, which is released from local axonal endings of PV neurons. These findings indicate that activation of PV neurons in the TRNrd increases pain sensitivity in PV-Cre transgenic mice.