Short- and long-term effects of perinatal asphyxia on monoamine, amino acid and glycolysis product levels measured in the basal ganglia of the rat

Birth Insult Alters Dopamine-Mediated Behavior in a Precocial Species, the Guinea Pig Implications for Schizophrenia

“…to the one used in the current study, rat neonates are able to survive up to 20-22 min of added anoxia, without artificial resuscitation (Loidl et al 1994;Boksa et al 1995;Chen et al 1995Chen et al , 1997. However, guinea pigs survived only 2 min of birth anoxia due to the relative maturity of guinea pig CNS at birth.…”

“…In contrast to the long term changes in dopaminergic parameters already mentioned (Brake et al 1997b; El-Khodor and Boksa 1997, 1998;) (El-Khodor and Boksa, submitted), adult rats born by C-section with or without 15 min of added anoxia show no changes in levels of serotonin, 5-hydroxyindole acetic acid or norepinephrine in nucleus accumbens, striatum and prefrontal cortex, compared to vaginal birth (El-Khodor and Boksa 1997). Chen et al (1997) have reported no change in levels of glutamate or aspartate in striatum, nucleus accumbens, ventral tegmental area and substantia nigra in 8-day-old rats that had been born by C-section with or without 2 to 22 min of anoxia. Additionally, 4-week-old rats born by C-section or by C-section with 20-21 min of anoxia showed no significant change in basal or K ϩ -evoked glutamate or GABA release from the striatum, compared to vaginal birth, whereas basal glutamate release was decreased in rats born by C-section plus 21-22 min of anoxia (Chen et al 1997).…”

“…Chen et al (1997) have reported no change in levels of glutamate or aspartate in striatum, nucleus accumbens, ventral tegmental area and substantia nigra in 8-day-old rats that had been born by C-section with or without 2 to 22 min of anoxia. Additionally, 4-week-old rats born by C-section or by C-section with 20-21 min of anoxia showed no significant change in basal or K ϩ -evoked glutamate or GABA release from the striatum, compared to vaginal birth, whereas basal glutamate release was decreased in rats born by C-section plus 21-22 min of anoxia (Chen et al 1997). Thus, of the systems investigated in the rat model, dopaminergic systems appear to exhibit the greatest dysregulation compared to serotonin, glutamate, or GABA.…”

“…Using a rat model of global hypoxia during Caesarean section (C-section) birth, several laboratories have demonstrated that dopaminergic systems are sensitive to mild birth alterations (Bjelke et al 1991;Loidl et al 1994;Chen et al 1995Chen et al , 1997 Brake et al 1997a,b; Boksa 1997, 1998;Vaillancourt and Boksa 1998; Berger et al 2000a). Specifically, as adults, rats born by C-section, either with or without addition of a period of global hypoxia, show increased nucleus accumbens dopamine (DA) release in response to repeated stress (Brake et al 1997b) Vaillancourt et al 1999), similar to the reported increased incidence of mild respiratory distress in humans born by C-section (Hales et al 1993).…”

Caesarean Section Birth Produces Long Term Changes in Dopamine D1 Receptors and in Stress-induced Regulation of D3 and D4 Receptors in the Rat Brain

“…Given these findings in schizophrenia, several studies have used a rat model of global anoxia during Caesarean section (C-section) birth to directly test if birth hypoxia alters later dopaminergic function and its responsiveness to stress (Bjelke et al 1991;Loidl et al 1994;Brake et al 1997a,b;Chen et al 1995Chen et al , 1997aElKhodor andBoksa 1997, 1998;Vaillancourt and Boksa 1998). These studies demonstrated that repeated stressinduced DA release from nucleus accumbens (NAcc) and amphetamine-induced behavioral responses are enhanced in adult rats that had been born by C-section, either with or without addition of 15 min of global anoxia, compared to vaginally born controls (Brake et al 1997b;El-Khodor and Boksa 1998).…”