Fig. 3. Neurogenesis of TH+ cells after 6-OHDA injection.
(A) Time course of cellular proliferation within the ventral
diencephalon and mesencephalon following sham- or 6-OHDA-lesioning. At days 7
and 10, a significant increase was seen in the number of BrdU+
cells in 6-OHDA-lesioned as compared with sham-lesioned animals. Control (grey
line) represents the number (3.1±1.5) of BrdU+ cells in
animals receiving no surgery/injection. Data represent mean±s.e.m.;
n=3-11; Student's t-test; *, P<0.05.
(B') Localisation of NeuN+ (neurons) and
GFAP+ (ependymoglia) cells along the third ventricle.
(B'') The cells lining the ventricle also express Sox2.
(C') Significantly more BrdU+ cells were seen away
from the ependymoglia layer at 13 days as compared with 6 hours after a single
BrdU pulse (n=3 lesion; n=3 sham; mean±s.e.m.;
Student's t-test; ***, P<0.001).
(C'') Merged confocal image showing several BrdU+
GFAP+ cells lining the ventricle 6 hours after BrdU pulse.
(C''') After a 13-day chase period, BrdU+ cells appear
in neuronal layers. (D') Total number of BrdU+
TH+ cells following lesioning. Sham-lesioned animals pulsed days
0-30, n=11; lesioned animals pulsed days 0-30, n=8. Lesioned
animals pulsed days 0-3, n=8. Lesioned animals pulsed days 4-23,
n=8. Mean±s.e.m.; ANOVA with Tukey post-hoc test;
***, P<0.001. (D'') Confocal image of two
BrdU+ TH+ neurons (arrows). (E) Total number of
cells (DAPI) and neurons (NeuN) in the TM at 3 and 30 days after lesioning
confirming that the number of cells returned to control levels by 30 days.
(F') Behavioural response following amphetamine challenge at day
3, 8 and 14 after AraC treatment. AraC has no effect on the behaviour of
control animals. However, it blocks all the behavioural recovery at 8 and 14
days normally seen in lesioned animals. (F'') AraC blocks all TH
recovery at 8 days and significantly reduces recovery at 14 days in lesioned
animals as compared with lesioned animals not treated with AraC
(mean±s.e.m.; Student's t-test; ***,
P<0.001). (F''') No new cells (BrdU+) were
seen at 8 days in AraC-treated lesioned newts confirming the action of AraC
(n=4-8 newts per group).