Glutamate and GABA Regulation by MK801 and Clozapine

All experiments were designed with equal-sized groups (n = 6) that were predetermined based on our previous studies [13 (link),14 (link),21 (link),48 (link)]. All values are expressed as mean ± standard deviation (SD), and a p-value less than 0.05 was considered statistically significant. Analyses were performed in IBM SPSS for Windows, Version 25 (IBM Corp., Armonk, NY, USA) and BellCurve for Excel ver. 3.00 (Social Survey Research Information Co., Ltd., Tokyo, Japan). The concentration-dependent effects of the local administration of MK801 (1, 10, and 50 μM) and CLZ (30, 100, and 300 μM) on extracellular levels of l-glutamate and GABA were compared using a linear mixed effects model (LME) (IBM SPSS), followed by Tukey’s post hoc test (BellCurve) when the F-value of the concentration factor was significant (Figure 1, Figure 2, Figure 3 and Figure 4). The effects of MK801, CLZ, LY341495, (RS)-α-cyclopropyl-4-phosphonophenyl glycine (CPPG), (S)-4-carboxyphenylglycine (CPG), and carbenoxolone (CBX) on an extracellular l-glutamate level were compared using LME, followed by Tukey’s post hoc test when the F-value of the drug factor was significant (Figure 5 and Figure 6). Particularly, the effect of the local administration of CPPG into the mPFC on the biphasic kinetics of l-glutamate release induced by CLZ was analyzed by LME followed by Tukey’s post hoc test when the F-value is the reciprocal factor of CPPG × time (Figure 5A,D). The concentration-dependent effects of CLZ on basal and on cystine- and K⁺-evoked astroglial l-glutamate release from primary cultured astrocytes were analyzed using logistic regression analysis (BellCurve) (Figure 7). The data and statistical analysis comply with the recommendations on experimental design and analysis in pharmacology [54 (link)].