Effects of pentylenetetrazol-induced seizures on dopamine and norepinephrine levels and on glucose utilization in various brain regions of the developing rat.
Levels of dopamine and norepinephrine were measured in seven brain areas after 60 min of sustained seizure activity induced by intraperitoneal repetitive timed administrations of pentylenetetrazol in rats at 10, 14, 17 and 21 days of postnatal life. The tissue levels of norepinephrine were markedly reduced in the majority of brain structures, except for striatum at 10 and 14 days. Conversely, dopamine concentrations increased in many areas and at various ages, except in cerebral cortex at 10 and 14 days and in midbrain between 14 and 21 days. PTZ seizures induced marked increases over control levels in the rates of glucose utilization, measured by the quantitative autoradiographic [14C]2-deoxyglucose method, in all dopamine- and norepinephrine-innervated areas studied at 10 and 14 days, except in cerebellar cortex at both ages and in frontal cortex and anteroventral thalamus at 14 days. At 17 and 21 days, glucose utilization remained increased over control levels in some areas, mainly in catecholaminergic cell groupings such as substantia nigra, ventral tegmental area and locus coeruleus, but was significantly reduced in cortex, caudate nucleus and thalamus, and similar to control rates in other regions. The present results suggest that pentylenetetrazol-induced seizures lead to a simultaneous increase in functional activity of norepinephrine neurons and an inhibition of dopaminergic-mediated neurons. They also confirm the maturation of connections, of metabolic activity and of neurotransmitter interaction within the brain, occurring mainly during the third week of postnatal life, paralleled by an increased selective vulnerability of some regions to this kind of insult.
el Hamdi
G
G
INSERM U 272, Université de Nancy I, France.
Boutroy
M J
MJ
Nehlig
A
A
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000254:growth & development; D001923:Brain Chemistry / Q000187:drug effects*; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D010433:Pentylenetetrazole; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism*
D005947:Glucose; D004298:Dopamine; D010433:Pentylenetetrazole; D009638:Norepinephrine