Figure 7

Very low glial reactivity in the spinal cord of Tg-treated animals. (a) Representative confocal Z-stack images of S100β immunofluorescence (green) in each experimental condition. Whereas in Non-Tg images, S100β appeared surrounding the nucleus, there was an increased density of positive swollen cells with coarse processes in Tg-untreated rats. Violacein treatment modulated both the number and appearance of S100β positive cells in the Tg-treated condition. Hoechst 33342 stained cell nuclei (blue). (b) Representative Z-stack images of GFAP immunofluroescences in all experimental conditions. Non-Tg and Tg-treated images exhibited delicate positive cell processes whereas in Tg-untreated rats there was a predominance of GFAP positive swollen cells with gross and short positive processes. (c) Confocal Z-stack images of the microglial cell marker Iba1 in all experimental conditions. Images from Non-Tg and Tg-treated sections showed positive cells with thin processes whereas in the Tg-untreated image there was an increased signal mostly present in swollen cells with short and coarse processes. Blood vessels were delicately positive to Iba1 . For each marker analyzed ((a), (b) and (c)), white arrows point positive cells representative of each experimental condition. Calibration: 100 µm, 40 µm and 20 µm for (a), (b) and (c), respectively. (d) Quantitation of S100β, GFAP and Iba1 cellular density related to Hoechst 33342 positive cells indicated that Tg-untreated versus Non-Tg samples had increases in S100β (p < 0.0001), GFAP (p < 0.0001) and Iba1 (p < 0.0001), respectively. Violacein caused less but yet significant increased values in Tg-treated versus Non-Tg conditions as indicated by S100β (p < 0.0001), GFAP (p < 0.0001) and Iba1 (p < 0.0001), respectively. In all cases, quantitation was done by measuring the cells that co-localized with Hoechst 33342 positive cell nuclei. Hoechst 33342 signal was omitted to emphasize violacein modulation of GFAP and Iba1 immunoreactivity in (b) and (c), respectively.