A comparison of neurodegeneration linked with neuroinflammation in different brain areas of rats after intracerebroventricular colchicine injection

Figures & data

Table 1. Memory parameter measures for the ICIR rats.

	ICIR rats
	Pre-injection	Post-injection
Memory parameters	Days 1–5	Day 9	Day 12	Day 15	Day 18	Day 21
Re-Entries: bited arms (Errors)	0	8.00 ± 0.01^a	8.58 ± 0.01^a	9.72 ± 0.02^a,c	11.76 ± 0.09^a,b	15.36 ± 0.53^a,b
Entries: unbited arms (Errors)	0	4.80 ± 0.20^d	10.23 ± 0.21^d,c	17.00 ± 0.37^d,c	19.70 ± 0.43^d,c	25.24 ± 1.53^d,c

Values at all timepoints for S and C rats were 0. Values shown are mean ± SEM (n = 6/group).

Number of re-entries in baited arms: ^aSignificant difference (p < 0.001) from pre-injection values for ICIR or for time-matched C or S rats; ^b,csignificant difference (^bp < 0.001, ^cp < 0.05) from previous timepoint value.

Number of entries in unbaited arms: ^dSignificant difference (p < 0.001) from pre-injection values for ICIR or for time-matched C or S rats; ^esignificant difference (p < 0.001) from previous timepoint value.

Figure 1. Nissl (cresyl violet) staining of neurons in different brain areas in rats. Representative micrographs are shown. Control rats: (A) (top row); sham-operated rats: (B) (middle row); ICIR [icv colchicine injected]: (C) (last row). Frontal cortex: 1 (left column), parietal cortex: 2 (middle column), occipital cortex: 3 (right column). Letter and number indicate group and specific brain region (e.g. A1: Frontal cortex, control rat). Magnification: 400 × , length of bar = 16.18 μm. Arrows indicate Nissl granules.

Figure 2. Nissl (cresyl violet) staining of neurons in different brain areas in rats. Representative micrographs are shown. Control rats: (A) (top row); sham-operated rats: (B) (middle row); ICIR [icv colchicine injected] rats: (C) (last row). Hippocampus: 4 (left column), corpus striatum: 5 (middle column), amygdala: 6 (right column). Letter and number indicate group and specific brain region (e.g. A4: Hippocampus, control rat). Magnification: 400 × , length of bar = 16.18 μm. Arrows indicate Nissl granules.

Figure 3. Intensity of Nissl granules in different brain areas of rats. Significant difference (p < 0.001) between control (C)/sham-operated (S) rats vs ICIR hosts in (a) frontal cortex, (b) parietal cortex, (c) corpus striatum, (d) amygdala and (e) hippocampus. In ICIR hosts, significant difference (p < 0.001) between (f) hippocampus/(g) frontal cortex vs amygdala, corpus stratum, occipital cortex. In ICIR hosts, significant difference (p < 0.01) between (h) parietal cortex vs corpus striatum. In control/sham operated hosts, significant difference (p < 0.01) between (i) hippocampus vs frontal, parietal and occipital cortex. A,Amygdala; CS, Corpus striatum; FC, Frontal cortex; H, Hippocampus; OC, Occipital cortex; PC, Parietal cortex. Values shown are means ± SEM (n = 6/group).

Figure 4. Staining (Congo red) of plaques in different brain areas in rats. Representative micrographs are shown. Control rats: (A) (top row); sham-operated rats: (B) (middle row); icv colchicine injected rats: (C) (last row). Frontal cortex: 1 (left column), parietal cortex: 2 (middle column), occipital cortex: 3 (right column). Letter and number indicate group and specific brain region (e.g, A1: Frontal cortex, control rat). Magnification: 400×, length of bar = 16.18 μm. Arrows indicate plaques.

Figure 5. Staining (Congo red) of plaques in different brain areas in rats. Representative micrographs are shown. Control rats: (A) (top row); sham-operated rats: (B) (middle row); icv colchicine injected rats: (C) (last row). Hippocampus: 4 (left column), corpus striatum: 5 (middle column), amygdala: 6 (right column). Letter and number indicate group and specific brain region (e.g. A4: Hippocampus, control rat). Magnification: 400×, length of bar = 16.18 μm. Arrows indicate plaques.

Figure 6. Number of plaques in different brain areas of intracerebroventricular colchicine injected rats (ICIR). Significant difference (p < 0.001) between hippocampus vs (a) frontal cortex; (b) parietal cortex; (c) corpus striatum; and (d) amygdala. Significant at p < 0.001 between amygdala vs (e) parietal cortex or (f) corpus striatum in ICIR hosts. Values shown are means ± SEM (n = 6/group). Abbreviations are as outlined in legend to Figure 3.

Figure 7. TNFα levels in different brain areas of rats. Significant difference between control (C)/sham-operated (S) rats vs ICIR hosts in (a) frontal cortex (p < 0.05), (b) amygdala (p < 0.001) and (c) hippocampus (p < 0.001). Significant difference (p < 0.001) between (d) hippo-campus/(e) amygdala vs frontal cortex, parietal cortex, occipital cortex and corpus striatum in ICIR hosts. Values shown are means ± SEM (n = 6/group). Abbreviations are as outlined in legend to Figure 3.

Figure 8. IL 1β levels in different brain areas of rats. (a) Significant difference (p < 0.001) between hippocampus levels in C and S rats vs in ICIR hosts. (b) Significant difference (p < 0.001) between hippocampus vs amygdala, frontal cortex, parietal cortex, occipital cortex and corpus striatum in ICIR hosts. (c) Significant difference (p < 0.05) between parietal cortex vs corpus striatum and occipital cortex in ICIR hosts. (d) Significant difference (p < 0.05) between hippocampus vs frontal cortex in control/sham operated rats. (e) Significant difference (p < 0.01) between hippocampus vs parietal cortex in C and S rats. Values shown are means ± SEM (n = 6/group). Abbreviations are as outlined in legend to Figure 3.

Figure 9. ROS levels in different brain areas of rats. (a) Significant difference (p < 0.001) between hippocampus levels in C and S rats vs in ICIR hosts. (b) Significant difference (p < 0.001) between hippocampus vs amygdala, frontal cortex, parietal cortex, occipital cortex and corpus striatum in ICIR hosts. Values shown are means ± SEM (n = 6/group). Abbreviations are as outlined in legend to Figure 3.

Figure 10. Nitrite levels in different brain areas of rats. (a) Significant difference (p < 0.001) between hippocampus levels in C and S rats vs in ICIR hosts. (b) Significant difference (p < 0.001) between hippocampus vs amygdala, frontal cortex, parietal cortex, occipital cortex and corpus striatum in ICIR hosts. Values shown are means ± SEM (n = 6/group). Abbreviations are as outlined in legend to Figure 3.