Neonatal 6-OHDA lesions upregulate adult expression of tyrosine hydroxylase mRNA.
We explored the consequences of postnatal day 1 (P1) intrastriatal 6-hydroxydopamine (6-OHDA) lesions on the developing mesostriatal dopamine system by performing in situ hybridization histochemistry for tyrosine hydroxylase (TH) in the substantia nigra-ventral tegmental area (SN-VTA) complex of neonatally-lesioned and non-lesioned animals at P90. There were significant reductions in the expression of TH mRNA from both the rostral and caudal levels of the lateral and medial SNc of 6-OHDA treated animals. The VTA was preferentially spared from the neurotoxic effects of 6-OHDA and showed elevated levels of TH mRNA in the caudal VTA compared with controls. This heterogeneous pattern of TH mRNA expression suggests that early intrastriatal 6-OHDA lesions selectively damage certain DA systems and affect the development of other systems.
Frohna
P A
PA
Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia 19104-6141.
Neal-Beliveau
B S
BS
Joyce
J N
JN
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001923:Brain Chemistry / Q000502:physiology; D004298:Dopamine / Q000502:physiology; D005260:Female; D006651:Histocytochemistry; D017403:In Situ Hybridization; D008636:Mesencephalon / Q000201:enzymology / Q000254:growth & development; D015345:Oligonucleotide Probes; D016627:Oxidopamine; D011247:Pregnancy; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis*; D015854:Up-Regulation / Q000187:drug effects*
D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D016627:Oxidopamine; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine