Thus, we detected the levels of glutamate in the cerebral cortex and hippocampus of mice. receptors were detected in a variety of ways. The protective mechanism of PBMT was further studied by stimulating CPDA primary astrocytes and neurons with CORT to construct a pathological model (ab75991), rabbit polyclonal AMPA receptor (ab183797), Alexa Fluor? 680 (ab175774), Alexa Fluor? 790 (ab175781), and Alexa 488/555-conjugated goat anti-mouse/rabbit anti-IgG (ab150113, ab150078) were purchased from Abcam Plc. (Cambridge, UK). Mouse monoclonal (sc365615), and mouse monoclonal GAPDH (sc47724) were bought from Santa Cruz Bio. (CA, USA). Rabbit polyclonal CPDA MAP2 (17490-1-AP), rabbit polyclonal NeuN (26975-1-AP), and rabbit polyclonal PSD95 (20665-1-AP) were purchased from ProteinTech. 2.2. Animals Five-week-old C57BL/6J male mice were purchased from Guangdong Medical Laboratory Animal Center, Guangzhou, China. Mice were housed in a standard laboratory environment (22 2C; 12?h light/dark cycle, with lights on from 07:00 to 19:00; and humidity: 50%-60%) and had free access to food and water except when mice were subjected to light/dark cycle disturbance or food/water deprivation stressors during the chronic unpredictable mild stress (CUMS) BIRC3 procedure. All of the experimental procedures were carried out in accordance with the protocols set and approved by the Institutional Animal Care and Use Committee of South China Normal University. 2.3. Experimental Design 2.3.1. Experiment 1: CUMS Procedure and PBMT Treatment (Related to Figure 1(a)) Open in a separate window Figure 1 Antidepressant effects of PBMT in CUMS- and CORT-induced mouse models of depression. (a) The experimental design of CUMS, treatment schedule, and behavioral tests. (bCd) PBMT significantly attenuated the decreased sucrose preference induced by CUMS but did not affect total fluid consumption. (e, f) PBMT significantly attenuated the increased immobility time of FST and TST induced by CUMS. (g) Glutamate concentration CPDA in CUMS-exposed mice was significantly higher than that in control mice, and PBMT could restore glutamate levels to normal (= 6 per group). (h) The experimental design of CORT, treatment schedule, and behavioral tests. (iCk) PBMT significantly attenuated the decreased sucrose preference induced by CORT but did not affect total fluid consumption. (l, m) PBMT significantly attenuated the increased immobility time of FST and TST induced by CORT. Number of mice used in behavior tests: control/vehicle, = 23 mice; CUMS, = 23 mice; CUMS+PBMT, = 14 mice; CORT, = 20 mice; and CORT+PBMT, = 14 mice. Data represent mean SEM. ns: not significant. ? 0.05, ?? 0.01, and ??? 0.001, one-way ANOVA with Tukey’s analysis. CUMS: chronic unpredictable mild stress; CORT: mice treated with corticosterone at a dose of 20?mg/kg for 28 days; PBMT: photobiomodulation therapy; SPT: sucrose preference test; FST: forced swimming test; TST: tail suspension test. C57BL/6J male mice were randomly divided into control and CUMS groups. The CUMS procedure was performed as previously described [53, 54], with some modifications, and the method’s description partly reproduces their wording. CUMS mice were housed in individual cages and were exposed to a variable sequence of 10 unpredictable and mild stressors: (1) food deprivation for 24?h, (2) water deprivation for 24?h, (3) clip the tail for 1?min (clamp 1?cm from the tip of the tail), (4) cold swimming at 8C for 10?min, (5) warm water swimming at 40C for 10?min, (6) soiled bedding overnight (150?mL of water in 100?g of sawdust bedding per cage), (7) reversal of the light/dark cycle, (8) restriction for 2?h (mice were restrained in a 50?mL centrifuge tube with holes for 2?h), (9) cage CPDA tilting 45 overnight, and (10) CPDA odor overnight (50?g of SD rats’ dirty sawdust bedding in 100?g of sawdust bedding per cage). Two kinds of stimulation were given at random every day, and the same kind of stimulation would not appear continuously to prevent habituation. After 6 weeks of stimulation, the mice underwent the depression-related behavioral tests. And then, the CUMS.