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.
Department of Histology and Neurobiology, Karolinska Institutet, Stockholm, Sweden.
B
B
Bjelke
K
K
Andersson
S O
SO
Ogren
P
P
Bolme
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