Chemoarchitecture and afferent connections of the "olfactostriatum": a specialized vomeronasal structure within the basal ganglia of snakes

The olfactostriatum, a portion of the striatal complex of snakes, is the major tertiary vomeronasal structure in the ophidian brain, receiving substantial afferents from the nucleus sphericus, the primary target of accessory olfactory bulb efferents. In the present study, we have characterized the olfactostriatum of garter snakes (Thamnophis sirtalis) on the basis of chemoarchitecture (distribution of serotonin, neuropeptide Y and tyrosine hydroxylase) and hodology (afferent connections). The olfactostriatum is densely immunoreactive for serotonin and neuropeptide Y and shows moderate-to-weak immunoreactivity for tyrosine hydroxylase. In addition to afferents from the nucleus sphericus, the olfactostriatum receives inputs from the dorsal and lateral cortices, nucleus of the accessory olfactory tract, external and dorsolateral amygdalae, dorsomedial thalamic nucleus, ventral tegmental area and raphe nuclei. Double labeling experiments demonstrated that the distribution of serotonin and neuropeptide Y in this area almost completely overlaps the terminal field of projections from the nucleus sphericus. Also, serotonergic and dopaminergic innervation of the olfactostriatum likely arise, respectively, from the raphe nuclei and the ventral tegmental area, whereas local circuit neurons originate the neuropeptide Y immunoreactivity. These results indicate that the olfactostriatum of snakes could be a portion of the nucleus accumbens, with features characteristic of the accumbens shell, devoted to processing vomeronasal information. Comparative data suggest that a similar structure is present in the ventral striatum of amphibians and mammals.     

瘦素（leptin）与肥胖

Obesity is a severely public health problem the whole society faces, and it is correlated closely with many diseases, such as diabetesⅡ, hypertension, coronary heart disease,gallqtone, and so on.Therefore it threatens people‘ s survival quality severely. Obesity is a multiple - factor disease including genetic, metabolic and behavioral factor, and the gene is the main determining factor. With the development of molecular biology technique, people have founded several genes involved in obesity. Among these genes, the research on obese gene is the most profound. The protein leptin is the expression product of the obese gene.This review elucidates the structure, the main biological function, the mechanism of leptin and it‘‘s relationship with obesity.     

Evans蓝用于鼠皮肤炎症反应损害程度的量化分析

目的：利用Evans蓝对由组胺和神经肽P物质引起的局部皮肤炎症损害、渗出，进行量化分析。方法：从Balb/c鼠尾静脉注射标定浓度的Evans蓝100 μL，麻醉后在脊背局部皮内分别注射20 μL组胺、神经肽物质P及生理盐水，15 min后处死动物，切下反应皮肤区，取约1 cm×1 cm×1 cm组织放入600 μL二甲酰胺溶液的小瓶中保存。实验时取出组织55 ℃避光孵育24 h，取200 μL孵化液用分光光度计进行测定，测量渗出的Evans蓝的吸光度进行定量分析。结果：Evans蓝注射后5 min给予组胺3.0 μg/0.2 cm2诱导效果最佳，可得到最大的Evans蓝吸光度。Evans蓝注射后10 min，给予0.1 μg/0.2 cm2神经肽P物质可得到最大的Evans蓝吸光度。Evans蓝在0.312-100 mg/L浓度范围内与吸光度呈线性关系。结论：Evans蓝可用于由组胺和神经肽P物质诱导的鼠局部皮肤炎症损害渗出的定量监测分析，所建立的评估超敏反应程度的方法简单、敏感且可定量。     

心包积液中几种多肽类物质的观察

目的 :为探讨C型利钠多肽 (CNP)、神经肽Y(NPY)、降钙素基因相关肽 (CGRP)在心包积液时的变化及其作用。方法 :用放射免疫分析测定心包积液患者的血液和心包积液中的CNP、NPY、CGRP水平。并与正常对照组的血液中的水平进行比较。结果 :血液和心包积液中的CNP显著高于对照组 (p <0 0 1) ,血液中NPY和CGRP则与对照组无显著性差异 (p >0 0 5 ) ,心包积液中NPY水平显著低于血液中 (p <0 0 5 ) ,心包积液中的CGRP水平则显著高于血液中 (p <0 0 1)。心包积液的量与心包积液中CNP、CGRP呈正相关 (r=0 71,p <0 0 1,r=0 5 7,p <0 0 1)与NPY呈负相关 (r=- 0 6 7,p <0 0 1) ,心包积液中的CNP、NPY和CGRP与其血液中的浓度间无显著相关性 (p >0 0 5 )。结论 :心包积液中有一定量的CNP、NPY和CGRP ,很可能由心包分泌。心包积液患者体内的CNP、NPY和CGRP的改变可能对心包积液的病理生理状况起到重要的调节作用。     

Intracerebroventricular infusion of neuropeptide Y up-regulates synthesis and accumulation of luteinizing hormone but not follicle stimulating hormone in the pituitary cells of prepubertal female lambs

Neuropeptide Y (NPY) is a putative neuroregulator of the reproductive axis in the central nervous system. In this study we evaluated the effects of central infusion of exogenous NPY on the secretory activity of pituitary gonadotrophic cells in prepubertal lambs. Immature female Merino sheep (n=12) were infused of Ringer solution (control) or 50 microg of NPY to the third ventricle for 5 min and then slaughtered 3 h later. Immunoreactive luteinizing hormone (LH) and follicle stimulating hormone (FSH) cells were localised by immunohistochemistry using antibody raised against LHbeta and FSHbeta. Messenger RNA analyses were performed by in situ hybridisation using sense and antisense riboprobes produced from beta subunits of LH and FSH cDNA clones. The results were generated by computer image analysis to determine the area fraction occupied by immunoreactive and/or hybridising cells and optical density for immunostaining and hybridisation signal. LH in the blood plasma was determined by radioimmunoassay. It was found, that in the lambs infused with NPY the area fraction and optical density for immunoreactive LH cells and mRNA LHbeta-expressing cells increased significantly (P<0.001), compared to the vehicle-infused animals. The concentration of LH in the blood plasma did not differ between control and treated groups. The NPY infusions had no effect on the immunoreactivity of FSH cells or on expression of mRNA for FSHbeta. In conclusion we suggest that NPY may be an important component of mechanisms stimulating the synthesis and storage but not the release of LH in the pituitary gonadotrophs from prepubertal female sheep. In addition, this effect is specific for LH, no such effect was apparent on FSH.     

Neuropeptide gene expression in brain is differentially regulated by midbrain dopamine neurons

Summary In situ hybridization was used to study the expression of prepro-neuropeptide Y (NPY), preprosomatostatin (SOM), preprotachykinin (PPT) and preprocholecystokinin (CCK) mRNA in caudate-putamen and frontoparietal cortex of rat brain with unilateral lesion of midbrain dopamine neurons. Neurons expressing NPY and SOM mRNA showed a similar distribution and the expression of both NPY and SOM appears to be regulated by dopamine in a similar fashion. Following a dopamine deafferentation, the numerical density of both NPY and SOM mRNA producing neurons almost doubled in the lesioned caudate-putamen with no change in the average grain density over positive neurons. Hence, in the intact caudate-putamen dopamine appears to suppress expression of these two neuropeptide genes leading to an activation of both NPY and SOM mRNA expression in many non- or low-expressing neurons when the level of dopamine is decreased. In the fronto-parietal cortex, on the other hand, dopamine appears to stimulate NPY and SOM gene expression. Thus, in the absence of dopamine about half of the NPY positive neurons disappeared. However, for SOM the number of positive neurons did not change, but rather most positive neurons appeared to have down-regulated their SOM mRNA expression. No evidence was found for a change in CCK mRNA expression by the dopamine deafferentation, while PPT mRNA expression decreased in the deafferented caudate-putamen. Consequently, dopamine exerts dissimilar effects on the expression of different neuropeptide genes, that in turn do not respond in the same way in different brain regions.     

Distribution of galanin-binding sites in the monkey and human telencephalon: preliminary observations

Summary Using X-ray film autoradiography the distribution of ¹²⁵I-galanin binding sites was studied in the forebrain of monkey and man. In the monkey a high density was found in all areas of the neocortex, especially layer 4, and in certain subfields in the hippocampal region. Also in the human brain high activity was seen in neocortex, mainly layer 6 and in hippocampal areas, as well as in amygdala, piriform cortex and hypothalamus. These results suggest that the 29-amino acid peptide galanin may be involved in the regulation of higher cortical functions in primates.     

交感神经化学切除后大鼠心窦房结区神经递质的变化

用６－羟多巴胺化学切除大鼠心内交感神经后，有免疫组织化学结合图像分析法和放免测定观察窦房结区神经肽Ｙ及降钙素基因相关肽的变化；同时应用组织化学方法结合图像分析、生物化学测量观察了ＳＡＮ区去甲肾上腺素及乙酰胆碱酯酶的变化，实验发现，静脉注射６－ＯＨＤＡ５０ｍｇ／ｋｇ一周后，ＳＡＮ区ＮＡ及ＮＰＹ含量明显减少，ＡＣＨＥ活性显著增加，ＣＧＲＰ含量增加不明显。     

Galanin-positive nerves of trigeminal origin innervate rat cerebral vessels

Galanin (GAL)-positive nerve fibers in rat cerebral vessels were demonstrated by immunohistochemistry, and their origin in the trigeminal ganglia and pathway in the nasociliary nerve to the vessels was shown by retrograde tracer technique and nerve transection. Some fibers in the vertebrobasilar system appear to originate in extracranial sources. With the antiserum used only few GAL fibers could be seen in the vessels, mostly in the vertebrobasilar system. In neonatally sympathectomized animals a rich network could be visualized in most pial arteries - still particularly in the vertebrobasilar system - probably as a result of a diminished competition for nerve growth factor. No vasomotor effect of GAL could be detected in isolated segments of pial arteries, neither in normal nor in sympathectomized animals, which rules out a direct postsynaptic effect on vascular tone. GAL did not display prejunctional modulatory action on the adrenergic nerves present in the vascular preparations. A sensory function of GAL is discussed.     

Effects of carotid sinus nerve transection on changes in neuropeptide Y and indolamines induced by long-term hypoxia in rats

 Long-term hypoxia induces changes in neuropeptide-Y-like immunoreactivity (NPY-LI) and/or in the content of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) at the central level. To determine whether these alterations depend on the integrity of carotid body (CB) chemoreceptors, intact rats or those whose carotid sinus nerve was transected (CSNT) were exposed to hypoxia (10% O₂) or to normoxia for 14 days. Thereafter, NPY-LI, 5-HT and 5-HIAA levels in discrete brain regions were determined. The increase in NPY-LI in the ventrolateral medulla oblongata (VLM) of intact hypoxic rats was mostly abolished after CSNT and therefore is mainly mediated by CB chemoreceptors. In contrast, other hypoxia-induced changes were similar or even enhanced in CSNT as compared to intact rats and therefore do not depend on the integrity of CB chemoreceptors. This was the case for the increase of NPY-LI in the striatum and the caudal dorsomedian medulla oblongata (DMM), as well as for all the changes in 5-HT and 5-HIAA in the DMM, the VLM, the raphe nuclei, the striatum and the frontal cortex. We propose that long-term hypoxia alters brain NPY-LI and indolamine content through the stimulation of CB chemoreceptors or ancillary chemoreceptors, as well as through local biochemical or morphological mechanisms. Received: 5 May 1998 / Received after revision: 27 July 1998 / Accepted: 3 September 1998