Lipocalin 2 in the Paraventricular Thalamic Nucleus Contributes to DSS-Induced Depressive-Like Behaviors / 神经科学通报·英文版

The incidence rate of anxiety and depression is significantly higher in patients with inflammatory bowel diseases (IBD) than in the general population. The mechanisms underlying dextran sulfate sodium (DSS)-induced depressive-like behaviors are still unclear. We clarified that IBD mice induced by repeated administration of DSS presented depressive-like behaviors. The paraventricular thalamic nucleus (PVT) was regarded as the activated brain region by the number of c-fos-labeled neurons. RNA-sequencing analysis showed that lipocalin 2 (Lcn2) was upregulated in the PVT of mice with DSS-induced depressive behaviors. Upregulating Lcn2 from neuronal activity induced dendritic spine loss and the secreted protein induced chemokine expression and subsequently contributed to microglial activation leading to blood-brain barrier permeability. Moreover, Lcn2 silencing in the PVT alleviated the DSS-induced depressive-like behaviors. The present study demonstrated that elevated Lcn2 in the PVT is a critical factor for DSS-induced depressive behaviors.

study on the postnatal development and aging changes of the neurosecretory nuclei of the hypothalamus [supraoptic and paraventricular nuclei] in the albino rat

The hypothalamus is a distinct neurological entity concerned with a variety of regulatory processes. Recently, the prescence of variations in the level of neurosecretions wth the progress of age was reported. To study the changes in the structure of magnocellular neurons in the paraventricular and supraoptic nuclei during the period of postnatal development. Furthermore, to study the changes which occurred in the structure of these neurons in the old age had been studied. A total of 52 albino rats were used. The age groups of the animals include: one day, 10 days, 20 days, 2 months and 2 years old animals. Brains were processed to be studied with Einarson's gallocyanin-chrome alum stain, Golgi- Cox method and transmission electron microscope. In addition, the number of cells in the magnocellular part of the paraventricular and supraoptic nuclei were measured in all studied age groups and statistically analyzed. In the newly born rats, the paraventricular and supraoptic nuclei were composed of small rounded condensed cells. At the age of 10 days old rats, the paraventricular nucleus appeared to be well differentiated into ventromedial [parvocellular] and dorsolateral [magnocellular] parts. With the progress of age from 10 days up to the adult stage, the cells of the supraoptic nucleus and the magnocellular part of the paraventricular nucleus appeared to be densely stained which indicated increase in the Nissl granules. Ultrastructural study showed that the cells had abundant amount of free ribosomes, rough endoplasmic reticulum and mitochondria. The nucleus had fine dispersed chromatin. Golgi-Cox study showed marked increase in extension and branching of dendrites with the progress of age during the developmental period. Morphometric study showed significant increase in the number of cells from the new born up to the adult stage. In old aged rats, the cells of the paraventricular nucleus and the supraoptic nucleus appeared to be faintly stained. Some cells had vacuolated cytoplasm. Ultrastructural study showed marked decrease in the free ribosomes and the presence of many lipofuscin pigment in the cytoplasm of cells. The nucleus showed chromatin condensation and irregularity of the nuclear membrane. In addition, there was apparent decrease in the amount of the synaptic vesicles in the presynaptic terminals making contacts with the magnocellular neurons. Golgi-Cox study revealed marked decrease in the extension and branching of dentrites. Morphometric analysis showed significant decrease in the number of cells. This study demonstrated in the presence of structural changes in the magnocellular part of the paraventricular nucleus and supraoptic nucleus during the period of development. In old age, the presence of many degenerative changes was observed. This cytoarchitectonic analysis and morphological study could help in the explanation of the functional differences in the various ages

Computational macroscopical patterning of the medullary striae of fourth ventricle

The aim of this study was to pattern macroscopically, by use of computational tools, the number and distributionof the medullary striae (MS) of fourth ventricle. After removing 71 fresh human brain stems, each respectiverhomboid fossa was photographed. The MS were carefully identified to be shaped and fulfilled by means ofa digital pen, using the Adobe Photoshop CS3® program. For absolute and relative analyses of number anddistribution, it was considered the maximum and minimum numbers of striae; striae that reached the ipsilaterallateral recess; presence of horizontal or oblique striae, with or without parallelism; and striae located at pontineor bulbar part of the rhomboid fossa. At least two MS per side were macroscopically detectable in 90.6% ofcases; they were bilaterally absent in 5.3% of pieces; and at least one medullary stria was present in both sidesof the rhomboid fossa in 92% of cases. As on the right side (36% of cases) as on the left (26.6%), two MS werefrequently more present. In 60% of cases, striae reached ipsilateral lateral recess on the left, and in 40% of caseson the right. It was detected horizontal, (non-parallel) oblique and parallel striae in 50.7, 86.7 and 26.7%of cases, respectively. Medial medullary striae were observed in the bulbar part of rhomboid fossa in 80% ofpieces, and in 36% of cases in the pontine part. The MS of fourth ventricle show high morphological variabilitydegree in relation to number and distribution.

Postnatal Development of Brain -Derived Neurotrophic Factor: Immunoreactive Neuron System of the Rat Brain / 대한해부학회지

BDNF is a protein that allows the survival and differentiation of the central nervous system. In the present study, we have examined the postnatal development of BDNF -immunoreactive (IR) neuron system in the forebrain and the upper brain stem of the rat using immunohistochemistry. In the piriform cortex, claustrum, CA2 and 3, anterodorsal and paraventricular thalamic nucleus (nu.), ventromedial hypothalamic nu. and substantia nigra, BDNF-IR neurons were detected at postnatal day 1. BDNF-IR neurons in the anterior olfactory n., layers V and VI of the neocortex, claustrum, dentate gyrus, basolateral amygdaloid nu., paraventricular hypothalamic nu., mammillary nu. first appeared at postnatal 1 week of age and tended to increase in number as the rats grew. BDNF -IR neurons in ventromedial and paraventricular hypothalamic nu., mammillary nu., and substantia nigra decreased in number and none or only a few BDNF-IR neurons were seen in these areas of the adult rats. However, after treatment of colchicine, these areas showed numerous BDNF-IR neurons. BDNF-IR axon terminals were found in the septal nu., central amygdaloid nu., bed nu., of the stria terminalis, anterior ventral, anterior medial, interanteromedial and paravertricular thalamic nu., at postnatal day 1 and in dentate gyrus and paraventricular hypothalamic nu., at 1 week of age, respectively. These terminals in general continued to increase in number as the rats grew. Our results showed that BDNF immunoreactivity increased in various regions of the postnatally developing rat brain and suggest that BDNF might play an important role in neuronal maturation.

Distribution of Brain-Derived Neurotrophic Factor-Immunoreactive Neurons in the Rat Brain after Colchicine Treatment / 대한해부학회지

Widespread brain-derived neurotrophic factor (BDNF) mRNA and protein expression has been detected in the brain. Despite substantial overlap between BDNF mRNA and protein expression, there is general anatomical regions, where there is discordance of these expression. We performed, therefore, immunohistochemistry after colchicine treatment into the ventricle to evaluate the possible presence of BDNF-immunoreactive (IR) in the regions where BDNF mRNA was expressed, but not BDNF-IR. The results obtained were as follows; There was substantial increase in the number of BDNF-IR neurons in the anterior olfactory nucleus, the piriform cortex, the cerebral cortex, the claustrum, the stratum pyramidale of the CA2 and the CA3, the granule cell layer of the dentate gyrus, the basolateral amygdaloid nucleus, the lateral geniculate nucleus, the anteromedial thalamic nucleus, the anterodorsal thalamic nucleus, the paraventricular thalamic nucleus, the paraventricular hypothalamic nucleus and the ventromedial hypothalamus nucleus, compared to the same brain area of non-colchicine treated rat. We detected many new BDNF-IR neurons in the stratum pyramidale of the CA1, A1, A2, A4-A10 cell groups, C1-C3 cell groups, the raphe magnus nucleus, the lateral paragigantocellular nucleus and the spinal vestibular nucleus. The results show that the localization of BDNF-IR neurons after colchicine treatment is consistant with that of BDNF mRNA containing neurons in the brain.

Location of CNS Labeled Neurons Innervating the Rat Thymus Using the Pseudorabies Virus / 체질인류학회지

This experimental studies was to investigate the location of CNS labeled neurons following injection of pseudorabies virus (PRV), Bartha strain, into the rat thymus. After survival times of 96~120 hours following injection of PRV, the rats were perfused, and their spinal cord and brain were frozen sectioned(30micrometer). These sections were stained by PRV immunohistochemical staining method, and observed with light microscope The results were as follows: 1. The PRV labeled spinal cord segments projecting to the rat thymus were founded in cervical and thoracic segments. Densely labeled areas of each spinal cord segment were founded in lamina V, VII, X, intermediolateral nucleus and dorsal nucleus. 2. In the rhombencephalon, PRV labeled neurons projecting to the thymus were founded in the A1 noradrenalin cells/C1 adrenalin cells/caudoventrolateral reticular nucleus, rostroventro-lateral reticular nucleus, medullary reticular nucleus, area postrema, nucleus solitary tract, nucleus raphe obscurus, nucleus raphe pallidus, nucleus raphe magnus, gigantocellular reticular nucleus, lateral paragigantocellular nucleus and spinal trigeminal nucleus. 3. In the mesencephalon, PRV labeled neurons were founded in parabrachial nucleus, Kolliker-Fuse nucleus, central gray matter, substantia nigra, nucleus dorsal raphe, A8 dopamin cells of retrorubral field, Edinger-Westphal nucleus, locus coeruleus, subcoeruleus nucleus and A5 noradrenalin cells. 4. In the prosencephalon, PRV labeled neurons were founded in reuniens thalamic nucleus, paraventricular thalamic nucleus, precommissural nucleus, paraventricular hypothalamic nucleus, anterior hypothalamic nucleus, lateral hypothalamic nucleus, preoptic hypothalamic nucleus, retrochiasmatic area, arcuate nucleus, dorsomedial hypothalamic nucleus and ventromedial hypothalamic nucleus. These results suggest that PRV labeled neurons of the spinal cord projecting to the rat thymus might be the neurons related to the viscero-somatic sensory and sympathetic preganglionic neurons, and PRV labeled neurons of the brain may be the neurons response to the movement of smooth muscle in blood vessels. These PRV labeled neurons may be central autonomic center related to the integration and modulation of reflex control linked to the sensory system monitoring the internal environment. These observations provide evidence for previously unknown projections from spinal cord and brain to the thymus which may be play an important role in the regulation of thymic function.

The Distribution of Brain-stem and Hypothalamus Fos like Immunoreactivity Associated with blockade of Superior Cervical Ganglion in Rats / 대한마취과학회지

BACKGROUND: Recently there have been many experiences regarding systemic effects of stellate ganglion block(SGB). During sympathetic hyperactivation, the SGB can be helpful to impaired microcirculation in brain-stem and hypothalamus. However, the exact mechanism and possible central action sites of SGB have not yet been investigated. In the present study, we traced central neural pathways following superior cervical ganglion block using the protein product(Fos) of c-fos protooncogene as a metabolic marker in a rat's brain. Method: The animals were divided into a superior cervical ganglion block group(n=5) using Marcaine 0.2 ml and a control block group(n=5) using saline 0.2ml. Medulla oblongata, pons, midbrain and hypothalamus were sectioned transversely with a sliding microtome. After imunohistochemical staining using rabbit polyclonal antibody we observed the distribution and grade of Fos expression under a light microscope. RESULTS: A blockade of superior cervical ganglion in rat led to the induction of c-fos in areas related to pain modulation sites and the autonomic nervous system; such as the parabrachial nucleus and central gray of the pons including dorsal raphe nucleus, as well as the substatia nigra of the midbrain, paraventricular hypothalamic nucleus, paraventricular thalamic nucleus posterior and habenular nucleus. CONCLUSIONS: Expressions of c-fos-like protein as a marker for neuronal activity following the blockade of the superior cervical ganglion in the rat have a part in the transcriptional control of the neurons which are related to the autonomic nervous system and endogenous pain modulation sites in the brain-stem.