Asphyctic lesion: proliferation of tyrosine hydroxylase-immunoreactive nerve cell bodies in the rat substantia nigra and functional changes in dopamine neurotransmission.
Asphyxia was induced in male rat pups by performing a delayed cesarean section on pregnant Sprague-Dawley rats. Oxygen saturation and heart rate were recorded during induction of asphyxia. Animals were sacrificed at 3 weeks of age. Brain sections were stained for tyrosine-hydroxylase (TH), dopamine-and-cyclic-AMP-regulated-phosphoprotein-32 (DARPP-32) immunoreactivity (IR) and thionein. Increasing time of asphyxia caused a reduction in the number of nerve cell bodies in the CA1 and CA3 regions of the hippocampus reflecting neuronal death. Furthermore, asphyxia resulted in an increased number of TH-IR nerve cell bodies indicative of a proliferation of dopaminergic neurons in the zona compacta of the substantia nigra. Finally, a significant decrease in rearing was observed in asphyctic animals during the habituation phase, as well as following apomorphine-induced (1 mg/kg s.c.) postsynaptic dopamine receptor stimulation. On the other hand, the apomorphine-induced increase in locomotion was enhanced in asphyctic animals. The implications of these findings for hyperkinesia and attention deficits in disorders resulting from asphyxia are discussed.
Bjelke
B
B
Department of Histology and Neurobiology, Karolinska Institutet, Stockholm, Sweden.
Andersson
K
K
Ogren
S O
SO
Bolme
P
P
D000818:Animals; D001238:Asphyxia Neonatorum / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology*; D001835:Body Weight; D001921:Brain / Q000033:anatomy & histology*; D002585:Cesarean Section; D004298:Dopamine / Q000502:physiology*; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D005260:Female; D006185:Habituation, Psychophysiologic; D006339:Heart Rate; D006801:Humans; D007231:Infant, Newborn; D008124:Locomotion; D008297:Male; D009043:Motor Activity; D009411:Nerve Endings / Q000201:enzymology / Q000648:ultrastructure*; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009474:Neurons / Q000166:cytology / Q000201:enzymology / Q000473:pathology*; D010750:Phosphoproteins / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D013378:Substantia Nigra / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology*; D009435:Synaptic Transmission; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine