Effect of Maternal Thyroxine Treatment on the Postnatal Development of Brain-derived Neurotrophic Factor-containing Purkinje Cell in Fetal Alcohol Effects in the Rat Cerebellum / 체질인류학회지

Maternal alcohol abuse is thought to be the common cause of mental retardation. Even moderate maternal alcohol consumption may produce fetal alcohol effects with behavioral and learning difficulties, if the drinking is associated with malnutrition. Especially, continuous alcohol consumption during critical period of brain development is very likely to produce fetal alcohol effects. The aims of this study are to investigate whether exogenous thyroxine treatment to alcohol -fed dams may ameliorate the detrimental effects of alcohol on the postnatal development of BDNF -containing Purkinje cell of the cerebellar cortex of the offspring. The morphological features of the growth and maturation were observed at 0, 7, 14, 21, 28 postnatal days via immunohistochemistry. In addition, electron microscopic finding of BDNF -containing Purkinje cell at P14 was also examined. Time -pregnant rats were divided into three groups. Alcohol -fed group received 35 calories of liquid alcohol diet daily from gestation day 6; control pair -fed group was fed a liquid diet in which dextrin replaced alcohol isocalorically; alcohol +/-T4 group received 35 calories liquid alcohol diet and exogenous thyroxine subcutaneously. As a result, a similar developmental pattern of BDNF -immunoreactive Purkinje cells was observed in control pair - fed and alcohol+/-T4 group on and after P14. These cells of alcohol -fed group showed immature features. Single -layer arrangement of these cells in alcohol -fed group was not completely achieved throughout postnatal life. Electron microscopic observations of BDNF -immunoreactive Purkinje cells at P14 revealed large nucleus, small cytoplasm, small amount of ribosomal collection and rudimentary cytoplasmic organelles in alcohol -fed group. The morphology of BDNF -immunoreactive Purkinje cell in alcohol +/-T4 group was similar to that in control pair -fed group. It was characterized by numerous short segments of rough endoplasmic reticulum, many of which showed a tendency of parallel alignment that suggested an attempt at Nissl body configuration. The cytology of Golgi complexes was also found within the cytoplasm in perinuclear location. Those observed differences of postnatal maturation patterns between alcohol -fed and alcohol +/-T4 group may indicate the beneficial effects on the postnatal development of BDNF -containing Purkinje cells in cerebellar cortex in the pups of thyroxine -treated alcohol -exposed dams. These results suggest that the increase of BDNF synthesis during early postnatal life caused by maternal administration of exogenous thyroxine may ameliorate fetal alcohol effects as a result of the dysthyroid state following maternal alcohol abuse.

Postnatal Development of Transforming Growth factor-alpha-immunoreactive Neurons in the Diencephalon of the Rat / 체질인류학회지

Transforming growth factor-alpha (TGF-alpha) immunoreactivity during postnatal development was examined in the rat diencephalon using immunohistochemistry. The time of appearance and localization of TGF-alpha immunoreactivity was slightly different in many areas of diencephalon during postnatal development. At birth, TGF-alpha immunoreactivity was mainly evident in thalamic medial, median and parafascicular thalamic nucleus of intralaminar nuclei. In addition, TGF-alpha immunoreactivity was clearly evident at the first postnatal week in most hypothalamic nuclei. Therefore, TGF-alpha immunoreactivity was found at postnatal days 7 in most diencephalic nuclei excepting the vental posterior thalamic nuclei, metathalamus and epithalamus. The quantitative increase of number was first apparent in the midline structures of thalamus in the first postnatal week. And then TGF-alpha-immunoreactive cells progressively increased throughout diendephalon by postnatal days 15. Adult patterns were reached at postnatal days 20. These results indicate that TGF-alpha-immunoreactive cells were first appeared in thalamic midline structures, increased progressively in the first two postnatal weeks, and followed mediolateral gradient. In addition to maturation of TGF-alpha-immunoreactive cells requires a relatively prolonged period of time to achieve an adult configuration. Also, the early appearance of TGF-alpha immunoreactivity in most diencephalic nuclei may be related to the early appearance of EGFR immunorecativity in many other brain regions. Taken together, these findings suggest that TGF-alpha immunoreactivity correlated with the appearance of the related functional activity in the different regions of diencephalon.

Immunocytochemical Localization of Transforming Growth Factor-alpha in the Forebrain of the Rat / 대한해부학회지

The distribution of Transforming growth factor-alpha (TGF-alpha) was examined in the rat forebrain by immunocytochemistry. TGF-alpha immunoreactivity was observed in the cerebral hemispheres, thalamus and hypothalamus. Neurons in the olfactory and septal area, cerebral cortex, hippocampus, striatum, amygdala, and different nuclei of the thalamus and hypothalamus showed immunoreactivity. The intensity of the immunoreaction was high in the hippocampus, pyramidal cell layers of cerebral cortex, reticular and ventral thalamic nuclei, and paraventricular and supraoptic hypothalamic nuclei. In addition, a few labelled glial cells appeared at random in the forebrain. These results indicate that both neurons and glial cells appear to synthesize TGF-alpha in normal forebrain of the rat. However, TGF-alpha immunoreactivity was more widely distributed in neurons than glial cells. Therefore, although the role of TGF-alpha in the central nervous system remains elusive, the present data support the concept that TGF-alpha may act as a trophic factor in the adult rat forebrain.

Immunocytochemical Studies of Calbindin D-28k and Parvalbumin-Containing GABAergic Neurons in the Midbrain of the Cat / 체질인류학회지

This study was carried out to investigate the morphology, distribution and co-localization of calbindin D-28k and parvalbumin-containing GABAergic cells in the midbrain of the cat. The results obtain by immunocytochemical observation were as follows : 1. Calcium binding protein calbindin D-28k and parvalbumin immunoreactive neurons were mainly found in the red nucleus, substantia nigra, oculomotor nucleus and locus ceruleus of the cat midbrain. 2. Parvalbumin immunoreactive cells in the red nucleus were more than twice in number compared to the calbindin D-28k immunoreactive cells. 3. Calbindin immunoreactive cells in the substans nigr were more than twice in number compared to the parvalbumin immunoreactive cells. 4. Double labelled immunocytochemical study revealed that parvalbumin and GABA were colocalized neurons in the same cells of the transverse section of the midbrain. 5. Calbindin D-28k and parvalbumin-immunoreactive cells were round, oval, spindle or polygonal in shape and were 15~20 micrometer in diameter. Positive neurons displayed unipolar, bipolar, or multipolar feature.