Publications (3)5.51 Total impact
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Article: Morphological evidence of an altered process of synaptic transcytosis in adult rats exposed to ethanol.
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ABSTRACT: Aims: The effects of ethanol exposure on synaptic structure were investigated in the nucleus of solitary tract (NST) in rats, using the horse-radish peroxidase (HRP) method. Methods: Eight-week-old experimental rats were allowed free access to a liquid diet containing ethanol for 3 weeks, while controls were given an isocaloric diet. Some of the control and experimental animals were given an injection of wheat germ agglutinin conjugated with HRP (WGA-HRP) into the vagus nerve toward the end of the treatment period. After the treatment, the neuropil region of the NST was examined under an electron microscope. Results: We observed that a few terminals were characterized by deep indentation of axodendritic membranes into the post-synaptic neurons. This appeared to be similar to that commonly seen in exocrine glands. Interestingly, the indented portion often contained various sizes of vacuoles and flattened cisternae. HRP-reaction product (RP) transported to terminals was recognized easily as an electron-dense lysosomal substance when lead citrate staining was omitted. Terminals containing HRP-RP also revealed quite a similar structure with indentation of axodendritic membranes as described earlier. The results are considered to confirm that terminals forming 'apocrine-like structures' observed in the ethanol-fed animals with no injection of WGA-HRP originate from afferent fibers of the vagus nerve. Conclusion: The present study suggests the possibility that the alteration of the synaptic structure induced by ethanol exposure can lead to the neuronal transcytosis of materials including proteins which is different from the normal vesicular exocytosis involved in chemical synaptic transmission.Alcohol and Alcoholism 08/2012; 47(6):671-6. · 2.95 Impact Factor -
Article: Neonatal repetitive maternal separation causes long-lasting alterations in various neurotrophic factor expression in the cerebral cortex of rats.
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ABSTRACT: This study was carried out to examine the effects of early postnatal maternal separation stress on the development of the cerebral cortex with respect to time-dependent fluctuations of neurotrophic factor ligand and receptor expression. Wistar rats were separated from their mothers for 3h per day during postnatal days (PND) 10 to 15. The cerebral cortex was analyzed by real-time RT-PCR for the evaluation of the expression of mRNA for brain-derived neurotrophic factor (BDNF), TrkB, insulin-like growth factor-1 (IGF-1), and type 1 IGF receptor (IGF-1R) on PND16, 20, 30, and 60. The expression of these neurotrophic factor ligands and receptors in the cerebral cortex was enhanced on PND16 and PND20, and then it returned to baseline levels on PND30. By PND60, however, the expression levels were attenuated. The important implication of this study is the persistent abnormal fluctuation of neurotrophic factor expression for a prolonged period, triggered even after the brain growth spurt. Given that neurotrophic factors play important roles in brain development, it can be speculated that the altered expression of these factors induced by maternal separation may interrupt normal brain development and ultimately lead to functional disruption. However, the possibility of such changes leading to various functional disruptions and the underlying mechanisms involved require further study.Life sciences 02/2012; 90(15-16):578-84. · 2.56 Impact Factor -
Article: GABA expression in c-Fos immunoreactive neurons of the rat periaqueductal gray induced by electroacupuncture at the point of Zusanli
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ABSTRACT: Immunofluorescent investigation of the periaqueductal gray (PAG) was made in the rat receiving electroacupuncture (EA) delivered to the acupoint (AP) called Zusanli (ST36) on the hindlimb. The EA led to strong expression of c-Fos-and gamma aminobutylic acid (GABA)-immunoreactivity (IR) mainly in the ventrolateral to lateral subdivision of the PAG. The double immunofluorescent experiments showed GABA expression in c-Fos immunoreactive neurons in the PAG. Morphometric analysis revealed that the number of double-labeled neurons in the AP case is approximately three times higher than that in the non-AP case. The present findings might indicate that PAG neurons activated by the EA at the AP of Zusanli participate in the descending pain control system of GABA.
