Journal of chemical neuroanatomy
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J. Chem. Neuroanat. · Nov 2010
Single-prolonged stress induced mitochondrial-dependent apoptosis in hippocampus in the rat model of post-traumatic stress disorder.
Post-traumatic stress disorder (PTSD) is a stress-related mental disorder caused by experience of a traumatic event, and presents with characteristic symptoms including intrusive memories, hyperarousal, and avoidance. Recently, structural neuroimaging studies showed that hippocampal volumes were relatively low in PTSD patients. However, the mechanisms that cause such atrophy are not well understood. ⋯ Apoptotic cells were assessed by TUNEL method. Our results showed apoptotic cells were significantly increased in hippocampus of SPS rats, accompanied by release of cytochrome c from the mitochondria into the cytosol, increase of caspase-9 and caspase-3 expression and decrease of the Bcl-2/Bax ratio. The results indicate that SPS-induced apoptosis in hippocampus of PTSD rats, and the mitochondrial pathway was involved in the process of SPS-induced apoptosis.
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J. Chem. Neuroanat. · Oct 2010
Regulatory mechanism of hypothalamo-pituitary-adrenal (HPA) axis and neuronal changes after adrenalectomy in type 2 diabetes.
Diabetes, especially type 2, is closely associated with hypothalamo-pituitary-adrenal (HPA) axis regulation. Short-term effects of adrenalectomy (ADX) in type 2 diabetes are well characterized; however, there have been few reports on the long-term effects of ADX in genetically engineered type 2 diabetes and the neuroendocrine system. We performed bilateral ADX in Zucker Lean Control rats (ZLC; ADX-ZLC), Zucker Diabetic Fatty rats (ZDF; ADX-ZDF), and sham control rats to evaluate how the HPA axis would be regulated in long-term corticosterone deficient type 2 diabetic animals. ⋯ The long-termed lack of corticosterone in the blood stream is a very important factor for normal regulation of the HPA axis even in diabetic animals. From the data, we can conclude that the stimulated HPA axis regulation in the developing type 2 diabetic animals following long-term adrenalectomy has remained elevated rather than diminished. Therefore, the current study may provide useful information to better understand patients suffering from both type 2 diabetes and Addison's disease.
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J. Chem. Neuroanat. · Oct 2010
Early expression of injury-induced neuropeptide Y in primary sensory neurons and the cuneate nucleus in diabetic rats with median nerve transection.
In this study we examined the temporal changes in neuropeptide Y (NPY) expression in dorsal root ganglion (DRG) neurons and cuneate nucleus (CN) in streptozotocin (STZ)-induced diabetic rats with or without median nerve transection (MNT). Numerous NPY-like immunoreactive (NPY-LI) neurons and fibers were detected in the DRG and CN of the diabetic MNT (DMNT) rats respectively, but not in those with diabetes-alone. Following MNT, the time-course of NPY expression pattern in the diabetic DRG and CN was similar and both peaked at 2 weeks, which was earlier than those in the non-diabetic MNT rats. ⋯ In the diabetic CN, the number of c-Fos-LI cells also peaked at 2 weeks after MNT, which was consistent with the temporal pattern of changes in NPY expression. The results suggest that in diabetes, MNT induced NPY expression via the reduction of NT-3, and electrical stimulation of the injured median nerve evoked the release of NPY and accordingly more c-Fos-LI cells were identified in the CN. Furthermore, this study demonstrated early NPY and c-Fos expression in the diabetic rats after MNT, suggesting that the development of neuropathic signs may be advanced in hyperglycemic rats.
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J. Chem. Neuroanat. · Jul 2010
Expression profile of multiple secretory phospholipase A(2) isoforms in the rat CNS: enriched expression of sPLA(2)-IIA in brainstem and spinal cord.
Phospholipases A(2) (PLA(2)) are enzymes which cleave the sn-2 ester bond in membrane phospholipids to release free fatty acids and lysophospholipids. The present study aimed to elucidate the expression profile of multiple secretory phospholipase A(2) (sPLA(2)) isoforms in the normal rat CNS with focus on sPLA(2)-IIA in the brainstem and spinal cord. Quantitative RT-PCR analysis showed that sPLA(2)-IB expression was low throughout the CNS, sPLA(2)-IIA expression was high in the brainstem and spinal cord, sPLA(2)-IIC expression was high in the cerebral neocortex, hippocampus and thalamus/hypothalamus, sPLA(2)-V expression was high in the olfactory bulb and cerebellum, and sPLA(2)-X was expressed at very low levels in the normal CNS. ⋯ Western blot analysis showed high level of sPLA(2)-IIA expression in the brainstem and cervical, thoracic and lumbar spinal segments but low level of expression in other parts of the brain. sPLA(2)-IIA was localized by immunohistochemistry to the spinal trigeminal and facial motor nuclei and dorsal- and ventral-horns of the spinal cord. The enzyme was found on the endoplasmic reticulum of neuronal cell bodies and small diameter dendrites or dendritic spines at electron microscopy. The expression of sPLA(2)-IIA in the dorsal horn and spinal trigeminal nucleus is consistent with previous results which showed an important role of CNS sPLA(2) in nociceptive transmission.
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J. Chem. Neuroanat. · Sep 2009
Expression patterns of 5-HT receptor subtypes 1A and 2A on GABAergic neurons within the spinal dorsal horn of GAD67-GFP knock-in mice.
5-HT plays an important role in GABA transmission at the spinal cord level. The main purpose of the present article is to find out, which 5-HT receptor subtypes may be involved in the regulation of GABAergic transmission in the spinal dorsal horn, by using the combination of tissue RT-PCR, single-cell RT-PCR and double immunofluorescent staining on the GAD(67)-GFP knock-in mice. The present result showed that 5-HT(1A) receptor subtype mRNA was present on about half of GFP-positive GABAergic interneurons in the spinal dorsal horn, which suggests a role of 5-HT(1A) receptor in GABA-mediated modulation of nociception at the spinal cord level. However, it is unexpected that just a very limited sub-population of the total GABAergic interneurons express 5-HT(2A) receptor mRNA or proteins in the spinal dorsal horn, which suggests that the 5-HT(2A) receptor subtype may not be important for spinal GABAergic effects in nociceptive modulation.