Regional differences in the vulnerability of substantia nigra dopaminergic neurons in weaver mice.
Vulnerability of midbrain dopaminergic (DA) neurons in the weaver mouse was studied at postnatal (P) days 8 and 90, in chosen coronal levels throughout the anteroposterior (AP) extent of the substantia nigra pars compacta (SNc). Wild-type (+/+) and homozygous weaver (wv/wv) mice used were the offspring of pregnant dams injected in several cases with tritiated thymidine on embryonic days 11-15. DA neurons were identified for their tyrosine hydroxylase immunoreactivity. Data reveal that at P8, the frequency of both +/+ and wv/wv late-generated DA cells increases from rostral to caudal SNc. No apparent DA-cell loss was observed at P8 in the mutant genotype, irrespective of the AP level considered. However, throughout the AP, there was a significant reduction in the number of these neurons at any level in 90-day-old weavers. Comparison of P8 and P90 +/+ SNc suggests that cell death is not a major aspect in the developmental regulation of normal DA neurons, although numerical cell depletion in the postnatal development of weaver SNc probably results from the amplification of a basal cell-death process, which affected all the coronal levels studied.
Marti
Joaquín
J
Faculty of Biosciences, Department of Cellular Biology, Physiology and Immunology, Citology and Histology Unit, Autonomous University of Barcelona, Barcelona, Spain. joaquim.marti.clua@uab.es.
Santa-Cruz
María C
MC
Molina
Vanessa
V
Serra
Roger
R
Bayer
Shirley A
SA
Ghetti
Bernardino
B
Hervás
José P
JP
D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001345:Autoradiography / Q000379:methods; D002470:Cell Survival; D004298:Dopamine / Q000378:metabolism*; D004622:Embryo, Mammalian; D005260:Female; D051379:Mice; D008818:Mice, Neurologic Mutants / Q000033:anatomy & histology*; D009474:Neurons / Q000502:physiology*; D011247:Pregnancy; D013378:Substantia Nigra / Q000166:cytology / Q000196:embryology / Q000254:growth & development; D013936:Thymidine / Q000378:metabolism; D014316:Tritium / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D014316:Tritium; D014446:Tyrosine 3-Monooxygenase; D013936:Thymidine; D004298:Dopamine