A study of a dendritic marker, microtubule-associated protein 2 (MAP-2), in rats neonatally treated neurosteroids, pregnenolone and dehydroepiandrosterone (DHEA).

Neurosteroids administered during the neonatal period affect the development of several brain systems. We examined the effects of neonatal treatment with pregnenolone and dehydroepiandrosterone (DHEA) on a marker of neuronal dendrites, microtubule-associated protein 2 (MAP-2), in rat brain. Neonatal treatment with pregnenolone and DHEA increased the expression of MAP-2 in the hippocampus and nucleus accumbens but not in the prefrontal cortex, striatum or amygdala in adulthood.

Neuropathological examination of fetal rat brain in the 5-bromo-2'-deoxyuridine-induced neurodevelopmental disorder model.

The majority of prior developmental neurotoxicity studies focused on postnatal subjects rather than on the fetus. In the present paper, we demonstrate the use of histological examination of fetal rat (embryonic day 16.5) brain serial sections, employing Nissl staining and microtubule-associated protein 2 (MAP2) immunohistochemistry, in evaluating a chemical-induced neurodevelopmental disorder.

Locomotor hyperactivity following prenatal exposure to 5-bromo-2'-deoxyuridine: neurochemical and behavioral evidence of dopaminergic and serotonergic alterations.

Prenatal exposure to 5-bromo-2'-deoxyuridine (BrdU) has been reported to induce abnormal behaviors in offspring, including marked hyperactivity. In this study, the contribution of the serotonin (5-HT) and dopamine (DA) systems to BrdU-induced developmental neurotoxicity was investigated. Sprague-Dawley rats were treated with BrdU on gestational days 9 through 15 (50mg/kg, i.

5-Hydroxytryptamine7 (5-HT7) receptor immunoreactivity-positive 'stigmoid body'-like structure in developing rat brains.

We examined the expression of 5-hydroxytryptamine(7) (5-HT(7)) receptor protein in developing and adult rats with immunohistochemical technique. In adult male rats, 5-HT(7) receptor immunoreactivity was detected in the septum, striatum, indusium griseum, tenia tecta, thalamus, hippocampus and hypothalamus in the forebrain as well as the pons and cerebellum. In brains of 1, 7, 15 and 21 days old male rats but not of adult ones, 5-HT(7) receptor immunoreactivity-positive dot-like structures were detected.

Transient expression of S-100beta immunostaining in developing thalamus and somatosensory cortex of rat.

Serotonin is thought to affect the development of barrel fields in somatosensory cortex of rat and transient expression of the serotonin transporter has been reported in relevant thalamic (ventral posterior) and cortical (layer IV of parietal) regions in support of this. Much of the developmental role of serotonin is mediated by release of the neurotrophic protein S-100beta. The current work was thus undertaken to determine if S-100beta also shows a transient expression pattern in thalamus and barrel fields.

Effects of a neurosteroid, pregnenolone, during the neonatal period on adenosine A1 receptor, dopamine metabolites in the fronto-parietal cortex and behavioral response in the open field.

Neuronal dysfunction in the frontal cortex has been reported in the etiology of mental disorders, including schizophrenia. The adenosine A(1) receptor system, as well as the dopaminergic system, are important in the control of cortical neuronal activity. We hypothesize that neuroexcitability in early life is critical to the normal development of the brain, and neurosteroids are factors that modulate neuroexcitability during the development period.

A neuroactive steroid, pregnenolone, alters the striatal dopaminergic tone before and after puberty.

Neuroactive steroids are known to modulate excitability in neurons. Neuronal activity during early development is critical to normal development of the brain. A neuroactive steroid, pregnenolone, was administered (10 microg/g) to rats from postnatal day 3 (PD 3) through PD 7.