Disparity in the temporal appearance of methamphetamine-induced apoptosis and depletion of dopamine terminal markers in the striatum of mice.
Methamphetamine (METH) causes damage in the striatum at pre- and post-synaptic sites. Exposure to METH induces long-term depletions of dopamine (DA) terminal markers such as tyrosine hydroxylase (TH) and DA transporters (DAT). METH also induces neuronal apoptosis in some striatal neurons. The purpose of this study is to demonstrate which occurs first, apoptosis of some striatal neurons or DA terminal toxicity in mice. This is important because the death of striatal neurons leaves the terminals in a state of deafferentation. A bolus injection (i.p.) of METH (30 mg/kg) induces apoptosis (TUNEL staining) in approximately 25% of neurons in the striatum at 24 h after METH. However, in contrast to apoptosis, depletion of TH (Western blotting) begins to appear at 24 h after METH in dorsal striatum while the ventral striatum is unaffected. The peak of TH depletion (approximately 80% decrease relative to control) occurs at 48 h after METH. Autoradiographic analysis of DAT sites showed that depletion begins to appear 24 h after METH and peaks at 2 days (approximately 60% depletion relative to control). Histological analysis of the induction of glial fibrillary acidic protein (GFAP) by METH in striatal astrocytes revealed an increase at 48 h after METH that peaked at 3 days. These data demonstrate that striatal apoptosis precedes the depletion (toxicity) of DA terminal markers in the striatum of mice, suggesting that the ensuing state of deafferentation of the DA terminals may contribute to their degeneration.
Zhu
Judy P Q
JP
Department of Biological Sciences, Hunter College of the City University of New York, New York, NY 10021, USA.
Xu
Wenjing
W
Angulo
Jesus A
JA
D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D001345:Autoradiography / Q000379:methods; D015153:Blotting, Western / Q000379:methods; D002452:Cell Count / Q000379:methods; D003342:Corpus Striatum / Q000166:cytology*; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D018765:Dopamine Uptake Inhibitors / Q000633:toxicity*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D020287:In Situ Nick-End Labeling / Q000379:methods; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D008694:Methamphetamine / Q000633:toxicity*; D051379:Mice; D008813:Mice, Inbred ICR; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism; D013997:Time Factors; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D050483:Dopamine Plasma Membrane Transport Proteins; D018765:Dopamine Uptake Inhibitors; D005904:Glial Fibrillary Acidic Protein; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493215:Slc6a3 protein, mouse; D008694:Methamphetamine; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine