S. Diloreto et M. Balestrino, DEVELOPMENT OF VULNERABILITY TO HYPOXIC DAMAGE IN IN-VITRO HIPPOCAMPAL-NEURONS, International journal of developmental neuroscience, 15(2), 1997, pp. 225-230
We investigated the relationship between sensitivity to hypoxia and cu
lture age in in vitro hippocampal neurons. Hypoxia was induced by 24 h
r incubation in an oxygen-free environment. Up to 6 days in vitro (DIV
) mortality was very low or negligible, with few exceptions. Starting
at 7 DIV, significant mortality began to be observed: in the age range
7-10 DIV, mortality of 50% or more was observed in five out of 11 exp
eriments (45%) and average mortality was 51 +/- 15% (mean +/- standard
deviation, N = 11). In older (12-18 DIV) cultures, mortality of 50% o
r more was the rule (13 out of 13 experiments) and average mortality w
as 83 +/- 16% (mean +/- standard deviation, N = 13). The data could be
fitted by a sigmoid line (r = 0.87, P < 10(-6)) in which 50% mortalit
y corresponds to 8.6 DIV. The N-methyl-D-aspartate antagonist amino-ph
osphono-valerate and the nitric oxide synthase inhibitor nitroarginine
both provided protection. Degree of protection was comparable for the
two compounds, but was not observed in cultures younger than approxim
ately 7 DIV. By contrast, exogenous creatine was not protective, at va
riance with findings from other models. The data represent the first d
escription of how sensitivity to hypoxic damage varies during the life
time of an in vitro neuronal hippocampal culture. Moreover, they sugge
st the hypothesis that some maturational changes occurring at 7-9 days
in vitro may make previously resistant in vitro neurons significantly
sensitive to hypoxic damage, and that at least some of these changes
may reflect the development of N-methyl-D-aspartate-mediated glutamate
rgic transmission. (C) 1997 ISDN.