Fig. 1. (A ) Comparison of glycine transporter (GlyT) messenger RNA expression in different cell types of the central nervous system. In order to screen the different cell types obtained from rat cortical brain preparation for GlyT messenger RNA expression, quantitative real time polymerase chain reaction analysis was employed. Data are presented as mean ± SD (n = 4). (B–E ) GlyT1 and GlyT2 protein expression levels in primary astrocytes cell culture. Western blot analysis of GlyT protein expression revealed high GlyT1 protein (70 kDa) levels (B ) in primary astrocytes, whereas GlyT2 protein (87 kDa) (C ) was not detected. Homogenized tissue from brain and spinal cord was used as a positive control in both analyses, including brainstem regions, explaining the positive result for GlyT2 expression. Similarly, immunofluorescence microscopy in astrocytes indicated expression of GlyT1 (D ), but not of GlyT2 (E ). GlyT1 = glycine transporter 1; GlyT2 = glycine transporter 2.