Article Figures & Data
Figures
- Fig. 1.
Percent survival of TH-IR neurons in the substantia nigra of the time course study. The open barsrefer to the cell survival in non-GDNF-treated groups, whereas thefilled bars correspond to the cell survival of the GDNF recipients. Values are represented as the mean ± SEM (*p < 0.0001, significantly different from the 6-OHDA group at the 0 hr time point).
- Fig. 2.
Percent survival of TH-IR neurons in the ventral tegmental area. Cell survival of the non-GDNF recipients is shown in the open bars, whereas the filled barsdemonstrate the cell survival in GDNF-treated groups. Values are expressed as the mean ± SEM (**p < 0.05, significantly different from the 6-OHDA group at the 0 hr time point).
- Fig. 3.
Representative sections are shown through the midbrain of animals in all treatment groups processed for TH immunocytochemistry. A–C, The 0 hr time point. The 6-OHDA alone (A), citrate and 6-OHDA (B), and GDNF and 6-OHDA (C) treatment groups all show extensive loss of midbrain dopamine neurons. D, GDNF treatment 1 hr before 6-OHDA neurotoxicity also results in a severe loss of dopamine neurons in the substantia nigra. E, In contrast, at the 6 hr time point of GDNF administration, there is complete sparing of dopamine neurons in the substantia nigra. F,G, There is also significant sparing of dopamine neurons in the substantia nigra of animals treated with GDNF at the 12 and 24 hr time points, respectively, but this sparing does not seem to be as complete as the sparing observed at the 6 hr time point. A needle track (arrows) can be identified either above or entering the substantia nigra in all photomicrographs.
- Fig. 4.
Effects of cycloheximide on GDNF administration in the substantia nigra and ventral tegmental area. Values are expressed as the mean percent survival of TH-IR neurons ± SEM (*p < 0.05, statistically different from the saline plus citrate-treated group).
- Fig. 5.
Representative sections processed for TH immunocytochemistry of all treated midbrains of the cycloheximide study. A, Animals that received intranigral injections of saline and citrate and 6-OHDA show extensive loss of midbrain dopamine neurons. B, Similarly, there is also a severe depletion of dopamine neurons in the substantia nigra of animals treated intranigrally with cycloheximide and citrate and 6-OHDA.C, In contrast, animals treated with intranigral injections of saline and GDNF and 6-OHDA show complete sparing of nigral dopamine neurons. D, However, when the rat midbrain is treated with cycloheximide and GDNF and 6-OHDA, there is a significant depletion of nigral dopamine neurons reflecting the inhibition of GDNF neuroprotection by cycloheximide. The needle track is shown (arrow) in D passing through the substantia nigra.
Tables
Region Dopamine DOPAC Substantia nigra (SN) Citrate Left SN 1179 ± 162 382 ± 34 GDNF 995 ± 150 648 ± 123 Citrate Right SN 509 ± 199 175 ± 58 GDNF 1276 ± 204* 619 ± 981-160 Striatum (Str) Citrate Left Str 9749 ± 918 2298 ± 380 GDNF 10412 ± 1011 2747 ± 320 Citrate Right Str 3505 ± 1602 1137 ± 442 GDNF 8323 ± 1139* 2609 ± 3351-160
