Regional density of monoamine-accumulating amacrine cells in the rabbit retina

The spatial distribution of noradrenaline (NA)- and indoleamine-accumulating (IA) amacrine cells was studied by fluorescence microscopy in flatmounts and tangential cryosections (15 μm thickness) of albino rabbit retinas. The two classes of cells were found to be distributed over the retinal field in a mixed and random fashion. The regional density (mean ± S.D. cells/mm²) of monoamine-accumulating cells was highest in the visual streak (NA cells, 88 ± 5; IA cells, 1507 ± 92), and lowest (41 ± 7; 625 ± 105, respectively) in the inferior periphery. The density ratio of NA:IA cells was 1:15 on average. Among cells located in the amacrine cell layer, NA and IA cells accounted for 0.3 and 3.9% of the total cell population, respectively. Monoamine-accumulating amacrine cells displaced into the ganglion cell layer were few; these displaced cells were only 2% and 0.6% of the cell number of normally situated cells in the amacrine cell layer for NA and IA cells, respectively.     

Dye coupling between amacrine cells in carp retina

Amacrine cells in isolated retinas of the carp (Cyprinus carpio) were intracellularly recorded and marked with a fluorescent dye, Lucifer yellow. On occasion, dye coupling was found to occur between amacrine cells when the dye was iontophoretically injected into an amacrine cell, generating one of the transient or sustained types of photoresponse. Dye-coupled cells in the vicinity of the marked cell were very similar to the marked cell in soma shape and dendritic stratification. Dye diffusion is assumed to take place at gap junctions between dendrities of amacrine cells which belong to a population of similar type cells in morphology and possibly in function.     

Cell populations of the ganglion cell layer: displaced amacrine and matching amacrine cells in the pigeon retina

Summary The proportion and size distribution of ganglion and non-ganglion cells in the ganglion cell layer of different areas of the pigeon retina was examined in whole-mounts of the retina by retrograde axonal transport of horseradish peroxidase (HRP) from large brain injections. A maximum of 98% of cells were labelled in the red field and a maximum of 77% in the peripheral yellow field. Unlabelled cell bodies were 30% smaller than labelled ganglion cells and had a mean diameter of 6.2 m and a size range of 4 to 9 m. The morphology of cells in the ganglion cell layer was examined by Golgi staining of retinal whole-mounts. Small glia, displaced amacrine and ganglion cells were found. Displaced amacrine cell bodies were about 30% smaller than ganglion cells and their size distribution was similar to the unlabelled cells in HRP preparations. Displaced amacrine cells had small rounded cell bodies (mean diameter 6.2 m) increasing in size with eccentricity, and a unistratified dendritic tree of fine, nearly radial, varicose dendrites in sublamina 4 of the inner plexiform layer. They had elliptical dendritic fields (mean diameter 66 m) aligned parallel to the retina's horizontal meridian. A population of amacrine cells was found with somas at the inner margin of the inner nuclear layer and soma and dendritic morphology matching those of displaced amacrines. These amacrine cells had unistratified dendritic trees at the junction of sublaminae 1 and 2 of the inner plexiform layer. Pigeon displaced amacrine cells and their matching amacrines are similar to starburst cells of the rabbit retina. They may participate in on and off pathways to ganglion cells and their lamination suggests that they are cholinergic.     

Neuropeptide Y potentiates calcium-channel currents in single vascular smooth muscle cells

The effect of neuropeptide Y (NPY) on Ca²⁺- channel currents in isolated vascular smooth muscle cells was studied with the perforated-patch recording technique. Using Ba²⁺ (10 mM) as the charge carrier, inward currents sensitive to Cd²⁺ and nifedipine were potentiated by NPY in a concentration-dependent manner. The threshold concentration for the potentiating effect of NPY was 50 nM and reached a maximum at 150 nM. NPY shifted the steady-state activation curve to less positive membrane potentials by about 6 mV so that the potentiating effect was most prominent near the activation threshold of the current. It had no effect on steady-state inactivation of the current. These results suggest that NPY may potentiate vasoconstriction by promoting calcium entry through L-type voltage-dependent Ca²⁺-channels.     

用细胞原位杂交方法检测NPY mRNA在PC12细胞中的表达

目的：建立ＮＰＹ ｍＲＮＡ物细胞原位杂交检测方法,并以ＮＧＦ为诱导因子研究Ｄｅｘ对大鼠嗜铬细胞瘤ＰＣ１２细胞中ＮＰＹｍＲＮＡ表达的影响。方法：采用细胞原位杂交方法。方法：ＮＧＦ具有诱导ＮＰＹ基因表达的生物学效应且呈剂量效应关系;Ｄｅｘ对ＮＰｘＲＮＡ表达具有双相调节效应,即早期（〈８ｈ）可促进ＮＧＦ的诱导作用,而晚期（〉１６ｈ）则具有抑制作用（Ｐ〈０．０１）,但单独Ｄｅｘ对ＮＰＹｍＲＮＡ表达无显著影     

Bistratified amacrine cells in the retina of the tammar wallaby — Macropus eugenii

Summary Cajal (1911) noted that bistratified amacrine cells were common in non mammalian species and extremely rare in the mammalian retina. An examination of the marsupial retina of the tammar wallaby, stained with a modified Golgi procedure, revealed that a particular type of bistratified amacrine was frequently impregnated with the silver stain. Flat mount and transverse sections showed that the morphology of this cell did not correspond with any of the species-dependent bistratified amacrines reproduced in Cajal's drawings. Instead, the cell appeared to be almost identical to the AII or rod amacrine that has been observed in a number of mammalian retinas. The relative frequency with which the cell appears in our material, and its confirmed rod input in other species, are both consistent with the grazing habits of the tammar wallaby which is a crepuscular animal that does most of its feeding at dusk and after dark.     

维持性血透患者血小板提取液中NPY与NT的表达和意义

为研究慢性肾功能衰竭（ＣＲＦ）患者血液透析（ＨＤ）过程中血小板神经肽Ｙ（ＮＰＹ）与神经降压素（ＮＴ）的含量变化及其作用机制。从患者血闪中分离出血小板,采用放射免疫分析法,对血小板提取液和血浆中ＮＰＹ与ＮＴ含量进行ＨＤ前后的动态。结果显示：撮的血小板组比较,ＨＤ患者血小板提取液中ＮＰＹ含量明显降低,血浆中ＮＰＹ含量则明显增高,而血小板中提取液与血小板提取液中ＮＰＹ含量明显降低,血浆中ＮＰＹ含量则明显     

尿毒症患者血液透析治疗对瘦素和神经肽Y水平的影响

研究尿毒症患者血液透析前后血浆瘦素和血清神经肽Y(NPY)的变化,探讨改善尿毒症营养不良的有效措施.本文尿毒症患者69例,分为3组:低通量纤维素膜透析组(A组)32例,低通量血仿膜F6透析组(B组)21例,F60高通量血滤器透析滤过并血液透析组(C组)16例.对照组18名.用RIA测定患者透析前、后及对照组血浆瘦素及血清NPY水平.结果三组瘦素与NPY水平透析前明显高于对照组(P＜0.01);透析后A、B组瘦素、NPY水平未降低,C组瘦素水平明显降低(P＜0.05),但NPY无显著变化.尿毒症患者存在高瘦素及NPY血症,二者无相关性,都不能通过单纯血液透析清除.利用高通量血滤器进行血液滤过有助于增加瘦素的清除率,改善患者营养状态.     

Different Regulation of Atrial ANP Release through Neuropeptide Y2 and Y4 Receptors

Neuropeptide Y (NPY) receptors are present in cardiac membranes. However, its physiological roles in the heart are not clear. The aim of this study was to define the direct effects of pancreatic polypeptide (PP) on atrial dynamics and atrial natriuretic peptide (ANP) release in perfused beating atria. Pancreatic polypeptides, a NPY Y₄ receptor agonist, decreased atrial contractility but was not dose-dependent. The ANP release was stimulated by PP in a dose-dependent manner. GR 23118, a NPY Y₄ receptor agonist, also increased the ANP release and the potency was greater than PP. In contrast, peptide YY (3-36) (PYY), an NPY Y₂ receptor agonist, suppressed the release of ANP with positive inotropy. NPY, an agonist for Y_{1, 2, 5} receptor, did not cause any significant changes. The pretreatment of NPY (18-36), an antagonist for NPY Y₃ receptor, markedly attenuated the stimulation of ANP release by PP but did not affect the suppression of ANP release by PYY. BIIE0246, an antagonist for NPY Y₂ receptor, attenuated the suppression of ANP release by PYY. The responsiveness of atrial contractility to PP or PYY was not affected by either of the antagonists. These results suggest that NPY Y₄ and Y₂ receptor differently regulate the release of atrial ANP.     

COPD患者血清NPY含量及其临床意义

目的 :探讨慢性阻塞性肺病 (COPD)患者血清神经肽Y(NPY)水平的变化及其临床意义。方法 :采用放射免疫分析测定 4 0例COPD患者和 30例非COPD患者的血清NPY水平进行统计分析。结果 :COPD组血清NPY水平显著高于对照组 (130 36± 2 0 5 8) pg/mlvs (86 6 2± 13 0 2 ) pg/ml(t =10 .2 0 1,P <0 0 1)。Ⅰ、Ⅱ、Ⅲ期COPD患者间神经肽Y水平有显著差异 (F =2 0 .334,P <0 0 1)。结论 :COPD患者血清NPY显著升高 ,且与分期相关。     

Immunocytochemical localization of putative cholinergic neurons in the goldfish retina

The presence of putative cholinergic neurons in goldfish retina was demonstrated by immunocytochemical localization of choline acetyltransferase (ChAT), the synthesizing enzyme for acetylcholine. Four populations of ChAT-immunoreactive neurons were localized: two with cell bodies in the inner nuclear layer and two with cell bodies in the ganglion cell layer. The processes of these neurons ramified in lamina 2 and/or 4 (of 5) in the inner plexiform layer. These cell populations are comparable to populations of putative cholinergic neurons that have been identified by [3H]choline uptake [3, 10].     

Expression of somatostatin receptor subtype 5 in rat retinal amacrine cells

Somatostatin (SRIF), as a neuroactive peptide in the CNS, exerts its actions via five subtypes of specific receptors (ssts). In this work, the localization of sst(5) was studied immunocytochemically in rat retinal amacrine cells (ACs). Labeling for sst(5) was diffusely distributed throughout the full thickness of the inner plexiform layer (IPL) and formed two distinct fluorescence bands in the distal part of the IPL. Double labeling experiments showed that sst(5) was expressed in GABAergic ACs. It was further shown that labeling for sst(5) was observed in both dopaminergic and cholinergic ACs, stained by tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT), respectively. The immunostaining appeared mainly on the cell membranes and somatodendritic compartments of these ACs. For the cholinergic ACs, weak sst(5)-immunoreactivity was also observed in the processes terminating in the IPL. In contrast, no sst(5)-immunoreactivity was found in glycinergic AII ACs, stained by parvalbumin (PV). Furthermore, labeling for SRIF was co-localized with sst(5) in both dopaminergic and cholinergic ACs. These results suggest that sst(5) may serve as an autoreceptor or conventional receptor in retinal ACs.     

Neuropeptide Y and maternal behavior in the female native Thai chicken

Maternal care behaviors in birds include incubation and rearing behaviors. During incubating period, the hens stop laying and eating less due to food restriction as a natural fasting when compared with the rearing hens, resulting in low production of eggs and chicks. Neuropeptide Y (NPY), a neurotransmitter/neuromodulator, is very well known to be involved in food intake regulation in birds and mammals. The objective of this study is to elucidate the association between NPY and maternal behaviors in the female native Thai chicken. The distributions of NPY-immunoreactive (-ir) neurons and fibers in the brain of the incubating (INC), nest-deprived (ND), and replaced-egg-with-chicks (REC) hens at day 6 were determined utilizing immunohistochemistry technique. The results revealed that the distributions of NPY-ir neurons and fibers were observed within the septalis lateralis, nucleus rotundus, and nucleus dorsolateralis anterior thalami, with predominantly located within the the nucleus paraventricularis magnocellularis (PVN). NPY-ir fibers were located throughout the brain and the densest NPY-ir fibers were distributed in a discrete region lying close to the ventriculus tertius (third ventricle) through the hypothalamus. Changes in the number of NPY-ir neurons within the PVN of the INC, ND, and REC hens were compared at different time points (at days 6 and 14). Interestingly, the number of NPY-ir neurons within the PVN was significantly higher (P < 0.05) in the INC hens when compared with those of the ND and REC hens at day 14 but not day 6. In addition, the number of NPY-ir neurons within the PVN of the INC hens was significantly increased (P < 0.05) from day 6 to day 14 but not the ND and REC hens. These results indicated, for the first time, the asscociation between NPY and maternal behaviors in the femle native Thai chicken. Change in the number of NPY-ir neurons within the PVN during the transition from incubating to rearing behavior suggested the possible role of NPY in the regulation of the maternal behaviors in this equatorial species. In addition, the native Thai chicken might be an excellent animal model for the study of this phenomenon.     

神经肽Y与神经降压素两者比例失调在原发性高血压发病中的意义

为探讨神经肽Y(NPY)和神经降压素(NT)两者在原发性高血压(EH)发病中的意义,本文利用RIA法检测了298例EH患者血浆NPY和NT浓度。结果提示,EH患者血浆NPY浓度升高,与病情的严重程度呈正相关;NT浓度下降,与病情的严重程度呈负相关。NPY/NT比例明显升高,与病情相一致。NPY/NT比例失调可能是导致EH发病机制之一。     

Neuropeptide Y immunoreactive axons in the corpus callosum of the cat during postnatal development

Many immunocytochemical studies have identified different types of neurotransmitters localized in the corpus callosum (CC) axons in the adult mammal. Few studies have looked at the development of different neurochemically identified CC systems. Previous studies on the development of cat CC axons have indicated that a large number of transitory CC axons project to the cortex during early postnatal development. The present study focuses on the development of one neurochemically identified group of CC axons in the cat, labeled with an antibody against neuropeptide Y (NPY), to determine if this group participates in transitory CC axonal growth. Cats at specified ages from birth to adulthood were studied with a routine method of immunocytochemistry for antiserum to NPY. NPY-immunoreactive (ir) CC axons were detected at all stages examined, from newborn to adult; the peak density occurred during postnatal weeks (PNW) 3–4. During PNW 1–2, the denisty of NPY-ir CC axons increased gradually; some NPY-ir axons at this age had growth cones located within the CC bundle between the cerebral hemispheres. The density of the NPY-ir CC axons decreased gradually during PNW 5–7, and from PNW 8 to maturity only a few NPY-ir CC axons were observed. These results indicate that at least two types of NPY-ir CC axons (i.e., transitory and permanent) exist during development, and that most of these axons are eliminated or only express NPY-ir for a short period during development. The results also indicate that neurochemical subsets of CC axons participate in the extensive transitory growth observed by means of the membrane tracer DiI but they may follow unique developmental timetables.     

Neuropeptide Y immunoreactivity in the cat claustrum: A light- and electron-microscopic investigation

The claustrum is a telencephalic nucleus located ventrolateral to the basal ganglia in the mammalian brain. It has an extensive reciprocal connectivity with most if not all of the cerebral cortex, in particular, primary sensory areas. However, despite renewed and growing interest amongst investigators, there remains a paucity of data concerning its peptidergic profile. The aim of the present study was to examine the presence, morphology, distribution and ultrastructure of neuropeptide Y-immunoreactive (NPY-ir) neurons and fibers in the claustrum of the cat. Ten adult healthy cats from both sexes were used. All animals received human and ethical treatment in accordance with the Principles of Laboratory Animal Care. Subjects were irreversibly anesthetized and transcardially perfused with fixative solution containing glutaraldehyde and paraformaldehyde. Brains were promptly removed, postfixed and sectioned. Slices were incubated with polyclonal anti-NPY antibodies according to the standard avidin–biotin–peroxidase complex method adopted by our Department of Anatomy, Histology and Embryology. NPY-ir neurons and fibers were found to be diffusely distributed throughout the claustrum, with no obvious topographic or functional patterning other than larger numbers in its central/broadest part (stereotaxic planes A12–A16). Neurons were generally classified by diameter into three sizes: small (under 17 μm), medium (17–25 μm) and large (over 25 μm). Staining density is varied with some neurons appearing darker than others. At the electron-microscopic level NPY immunoproduct was observed within neurons, dendrites and terminal boutons, each differing relative to their ultrastructural attributes. Two types of NPY-ir synaptic boutons were found. Lastly, it is of interest to note that gender-specific differences were not observed.     

Expression patterns of the opsin 5-related genes in the developing chicken retina.

The opsin gene family encodes G protein-coupled seven-transmembrane proteins that bind to a retinaldehyde chromophore for photoreception. It has been reported that opsin 5 is expressed in mammalian neural tissue, but its function has been elusive. As a first step to understand the function for opsin 5 in the developing eye, we searched for chicken opsin 5-related genes in the genome by a bioinformatic approach and isolated opsin 5 cDNA fragments from the embryonic retina by RT-PCR. We found that there are three opsin 5-related genes, designated cOpn5m (chicken opsin 5, mammalian type), cOpn5L1 (chicken opsin 5-like 1), and cOpn5L2 (chicken opsin 5-like 2), in the chicken genome. Quantitative PCR analysis has revealed that cOpn5m is the most abundant in the developing and early posthatching neural retina. In situ hybridization analysis has shown that cOpn5m is specifically expressed in subsets of differentiating ganglion cells and amacrine cells. These results suggest that the mammalian type opsin 5 may contribute to the development of these retinal cells in the chicken.     

Neuropeptide Y inhibits Ca2+-activated K+ channels in vascular smooth muscle cells from the rat tail artery

The effects of neuropeptide Y (NPY) on the Ca²⁺-activated K⁺ channel in smooth muscle cells from the rat tail artery were studied by whole-cell and single-channel patch-clamp recording techniques. In the presence of nifedipine (1 M), whole-cell outward currents through Ca²⁺-activated K⁺ channels were inhibited by NPY in a dose-dependent manner from 20 to 200 nM. A maximum inhibition to about 48% of the control current could be achieved. Recordings from outside-out patches showed that the open probability of Ca²⁺-activated K⁺ channels were similarly inhibited by NPY. At 200 nM NPY, the open probability was reduced to about 36% of the control value. NPY did not affect the open times or current amplitude, but increased significantly the short (from 0.49 to 0.58 ms) and long (from 441 to 728 ms) closed times. Inhibition of Ca²⁺-activated K⁺ channels by NPY may contribute to its excitatory action on vascular smooth muscle cells.