Hypermotility induced by vasoactive intestinal peptide in the rat: its reciprocal action to cholecystokinin octapeptide

Intracerebroventricular administration of vasoactive intestinal peptide (VIP) shortened the duration of pentobarbital-induced sleep and produced significant hypermotility in the rat. Although hypermotility induced by methamphetamine was not potentiated by central administration of VIP, L-DOPA-induced hypermotility in pargyline-pretreated rats was markedly enhanced by VIP and this hypermotility was suppressed by simultaneous administration of cholecystokinin octapeptide (CCK-8) in a dose-related manner. Apomorphine-induced hypermotility was also potentiated by VIP. These results suggest that VIP may stimulate postsynaptic dopaminergic receptor, causing an increase in motility, and that a possible reciprocal interaction exists between VIP and CCK-8.     

蝮蛇毒抗凝血活酶组份及几种蛇毒粗毒对人红细胞和血小板的作用

蝮蛇毒抗凝血活酶组分及蝗蛇毒、圆斑蝰蛇毒和眼镜蛇毒粗毒,不仅能够水解血浆中的磷脂,而且还能水解完整人红细胞膜和完整人血小板膜上的磷脂。但是五步蛇毒和金环蛇毒粗毒却不能水解完整人血小板膜上的磷脂。 扫描电镜观察表明,由于抗凝血活酶组份和几种蛇毒粗毒的作用,人红细胞和人血小板的形态发生了巨大的变化;人红细胞由正常的双圆盘形变成带刺的小球,人血小板的外形变成蜂窝状。     

Immunocytochemical detection of 28000-MW calcium-binding protein in horizontal cells of the rat retina

Summary Horizontal cells of rat retina were labeled intensely by a specific antibody to cerebellar calcium-binding protein. The amacrine cells stained very weakly. The presence of calcium-binding protein in horizontal cells could be of interest for the understanding of the feedback action of these cells on photoreceptors.Abbreviations used CaBP calcium-binding protein - DAB 3,3-diaminobenzidine - PAP unlabelled antibody peroxidase-antiperoxidase immunocytochemical complex On leave from the Department of Physiology, University of British Columbia, Vancouver, Canada     

Influence of melatonin and serotonin on the number of rat pineal “synaptic” ribbons and spherules in vitro

Summary Previous studies have shown that the synaptic ribbons (SR) and spherules (SS) of the mammalian pineal gland may respond differently under physiological and various experimental conditions. The aim of the present study was to gain insight into the mechanisms that may be responsible for the numerical changes of these organelles during a 24-h cycle. As the possibility exists that the structures are influenced by substances synthesized within the pinealocyte, rat pineal glands were cultured with and without added melatonin or serotonin, using an experimental protocol such that the addition of melatonin and serotonin mimicks the circadian changes of the respective substances within the pineal. The tissue was processed for electron microscopy and the numbers of SR and SS were counted in a unit area of pineal tissue. The results obtained indicate that melatonin added to the incubation medium increases the number of SR in the first half of the night; serotonin decreases SR numbers in the morning. SS numbers, by contrast, decrease following melatonin administration in the afternoon, and increase in the morning following serotonin administration. It thus appears that the numbers of SR and SS are influenced by melatonin and serotonin and that the two structures are regulated by differential, but nevertheless biochemically closely related mechanisms.Financial support of the Deutsche Forschungsgemeinschaft (Schwerpunktprogramm Neuroendokrinologie, Vo 135/8-4), the Polish Academy of Sciences (Research Program 10.4.04.6), and the Freunde der Universität Mainz e.V. is gratefully acknowledged.On leave from Department of Anatomy, University Medical School, Pécs, Hungary     

Blood supply of the bed nucleus of the stria terminalis in rat

Summary The topographical distribution of the blood vessels in the bed nucleus of the stria terminalis (NIST) has been mapped in rats. Arteries and veins were visualized in red and blue by using a double-ink perfusion technique. Arteries supplying the NIST arise from the anterior cerebral artery directly or through the anterior communicating and interhemispheric arteries. Only a few, dorsal branches derive from the medial cerebral artery through thalamostriatal arteries. According to their terminal branches, NIST arteries can be divided into five groups: medial, ventral, lateral, septal and dorsal, which have only a relatively small overlap in their territories. About 90% of veins from the NIST drain into the major basal veins. Medial branches run into the perioptic and interhemispheric veins, while the ventral branches and the large lateral vein drain directly into the anterior cerebral vein. A small proportion of NIST veins run dorsalward into the vena cerebri magna via thalamostriatal veins.     

Ultrastructural localization of the calcium-binding protein parvalbumin in neurons of the song system of the zebra finch,Poephila guttata

Summary The distribution of parvalbumin (PV) within neurons of the vocal motor nucleus hyperstriatum ventralepars caudalis (HVc) was investigated in the forebrain of adult male zebra finches by means of light and electron microscopy using the indirect immunoperoxidase technique. Parvalbumin-reaction product was located in the amorphous material of perikarya, dendrites and nuclei, and associated to microtubuli, postsynaptic densities and intracellular membranes; it was found in some axons and Gray type-2 boutons, but rarely in type-1 boutons and never in the Golgi apparatus. These observations suggest that parvalbumin may regulate calcium-dependent processes at the postsynaptic membrane and in the cytosol. Furthermore, the partial association of parvalbumin to microtubuli points to an involvement in calcium-dependent tubular functions. Calcium currents and microtubular assembly or transport may be relevant for the known functions of HVc in song learning.     

Neuropeptides in the gastrointestinal canal of Necturus maculosus

Summary The presence and distribution of regulatory peptides in nerves and endocrine cells of the stomach, intestine and rectum of a urodele amphibian, the mudpuppy, Necturus maculosus, was studied immunohistochemically in sections or whole-mount preparations of the gut wall. The effect of the occurring peptides on gut motility was studied in isolated strip preparations of circular and longitudinal smooth muscle from different parts of the gut.Bombesin-, neurotensin-, substance P- and VIP-like immunoreactivity was present in abundant nerve fibres in the myenteric plexus of both stomach, intestine and rectum. Single fibres or bundles were present in the circular muscle layer and in a well-developed deep muscular plexus in the intestine and rectum. Immunoreactive nerve cells were found in the myenteric plexus of the stomach, intestine (neurotensin only) and rectum. Gastrin/CCK-like immunoreactivity was observed only in a few fibres in stomach and rectum.Endocrine cells containing bombesin-, met-enkephalin-, gastrin/CCK-, neurotensin-, somatostatin- or substance P- like immunoreactivity were present in the mucosa.The effect of bombesin was an inhibition of the rhythmic activity in circular muscle preparations and in longitudinal muscle from the rectum, while longitudinal muscle from the stomach usually responded with a weak increase in tonus. Neurotensin, like bombesin, was inhibitory on the spontaneous rhythmic activity of circular muscle throughout the gut, while the effect on longitudinal muscle was an increase in tonus. Met-enkephalin and substance P increased the tonus of all types of preparations, and often, in addition, initiated a rhythmic activity superimposed on this maintained tonus. VIP had a general inhibitory effect on the preparations, decreasing tonus and/or abolishing rhythmic activity.It is concluded that bombesin-, neurotensin-, substance P- and VIP-like peptides are present in nerves throughout the urodele gut and may have physiological functions in regulating the motility of the gut. The gastrin/CCK-like peptide present in nerves of the stomach and rectum may affect the function of these parts of the gut. The regulatory peptides present in endocrine cells may, perhaps with the exception of the somatostatin-like peptide, affect the motility humorally.     

Immunohistochemical localization of cyclic AMP and ultrastructural demonstration of adenylate cyclase activity in the testis of Esox lucius at time of spermiation

Summary In the testis of Esox lucius at the time of spermiation, activity of cyclic adenosine 3,5-monophosphate (cAMP) was immunocytochemically localized at the level of the Sertoli cells. In these cells adenylate cyclase activity was also ultracytochemically demonstrated by using adenylyl imidodiphosphate as a substrate. Reaction products of adenylate cyclase were primarily detectable on the basal and adluminal plasma membranes and on the surface of protrusions of the cell body into the lumen.     

The development of the human spleen

Summary Splenic tissue of human fetuses from the 14^th to the 24^th week of gestation (menstrual age) were investigated by light- and electron microscopy to describe the development of the red and white pulp in close relationship to the differentiation of the vascular tree. Special interest is focussed on the differentiation of the T-cell- and the B-cell regions and their specific stationary cells.The preliminary stage, here called the primary vascular reticulum, lasts up to the 14^th gestational week (gw). Numerous erythrocytes, normoblasts and macrophages are seen among a network of mesenchymal cells and argyrophilic fibers. Hematopoiesis, especially erythropoiesis, can be recognized.The characteristic organ structure becomes established during the subsequent transformation stage of the fetal spleen, beginning with the 15^th gw. Splenic lobules begin to form during the 15^th to 17^th gw. They consist of a central artery, surrounded by a sheath of lightly stained stationary cells which resemble myofibroblasts. At the periphery of these lobules the red pulp forms. Initially mobile cells are distributed throughout the reticulum. Soon they begin to accumulate in the venous sinuses, which develop from lacunae among the reticular network and come into contact with the venous system. The endothelial wall of these sinuses remains discontinuous, confirming the theory of the open vascularization of the spleen. The development of the larger veins is correlated with the differentiation of the splenic trabeculae.The development of the white pulp is correlated with the stage of lymphoid colonization within the spleen, beginning around the 18^th gw. An accumulation of lymphocytes around the central arteries can be recognized during the 19^th and 20^th gw. These lymphoid cells show morphological and immunohistochemical characteristics of T-precursor cells. Within the now assembling periarterial lymphoid sheath (PALS) a few precursors of interdigitating cells (IDC) are recognizable, giving evidence for the differentiation of the T-cell region.Around the 23^rd gw the assemblage of primary follicles is discernible at the periphery of the PALS. Precursors of the follicular dendritic reticulum cell (FDRC), the specific stationary cell of the B-cell region, have been recognized. This observation leads to the conclusion that the small primary follicles represent the beginning formation of the B-cell region.The significance of the vascular system for the differentiation of the specific splenic organization is discussed.This investigation was supported by grants from the Deutsche Forschungsgemeinschaft (Sonderforschungsbereich 111)The authors appreciate the contribution of human fetal material from Dr. von Hollweg and Dr. Körner from the Hospital Heidberg, Hamburg, and the excellent technical assistance of Mrs. H. Hansen, Mrs. I. Knauer, Mrs. M.v. Kolszynski, Mrs. J. Quitzau, Mrs. H. Siebke and Mrs. H. Waluk     

Multicellular antennal sensilla containing a sensory cell with a short dendrite and dense-core granules in the insect,Hypogastrura socialis (Collembola): intermolt and molting stages

Summary At the antennal tip of the collembolan insect Hypogastrura socialis two terminal-pore sensilla are located, which, in addition to normally structured and most probably chemosensitive sensory cells, also contain aberrant sensory cells. Portions of these cells resemble chemoreceptors but also shown are features that, as a rule, occur in mechanoreceptors. One cell in each sensillum is remarkable in two characteristics: (1) Its dendritic outer segment does not reach the cuticular outer structures of the sensillum; (2) it contains dense-core granules (diameter 60–110 nm) within its perikaryon, its dendritic inner segment and its axon. Additionally, these two cells do not show lengthening of their dendritic outer segment during molt as do all other sensory cells. Among the fibers of one major branch of the antennal nerve within the head capsule a single axon was observed to contain dense-core granules. This axon was traced to its termination where normal synaptical contacts were found. Based on the assumption that the axon belongs to one of the granule-containing sensory cells two alternative hypotheses are proposed: (1) an individual sensory cell of a sensillum may synthesize a transmitter that is different from that of the other sensory cells of this sensillum; (2) the aberrant cells have lost exteroceptive functions but act as neuromodulatorsSupported by the Deutsche Forschungsgemeinschaft (SFB 4/G1)