Serotonin immunoreactivity in the central nervous system of the marine molluscs Pleurobranchaea californica and Tritonia diomedea

The central nervous systems of the marine molluscs Pleurobranchaea californica (Opisthobranchia: Notaspidea) and Tritonia diomedea (Opisthobranchia: Nudibranchia) were examined for serotonin-immunoreactive (5-HT-IR) neurons and processes. Bilaterally paired clusters of 5-HT-IR neuron somata were distributed similarly in ganglia of the two species. In the cerebropleural ganglion complex, these were the metacerebral giant neurons (both species), a dorsal anterior cluster (Pleurobranchaea only), a dorsal medial cluster including identified neurons of the escape swimming network (both species), and a dorsal lateral cluster in the cerebropleural ganglion (Pleurobranchaea only). A ventral anterior cluster (both species) adjoined the metacerebral giant somata at the anterior ganglion edge. Pedal ganglia had the greatest number of 5-HT-IR somata, the majority located near the roots of the pedal commissure in both species. Most 5-HT-IR neurons were on the dorsal surface of the pedal ganglia in Pleurobranchaea and were ventral in Tritonia. Neither the buccal ganglion of both species nor the visceral ganglion of Pleurobranchaea had 5-HT-IR somata. Afew asymmetrical 5-HT-IR somata were found in cerebropleural and pedal ganglia in both species, always on the left side. The clustering of 5-HT-IR neurons, their diverse axon pathways, and the known physiologic properties of their identified members are consistent with a loosely organized arousal system of serotonergic neurons whose components can be generally or differentially active in expression of diverse behaviors.     

Neuronal elements that mediate escape swimming and suppress feeding behavior in the predatory sea slug Pleurobranchaea

1. The white, bilaterally paired A1 interneurons of the cerebropleural ganglion of Pleurobranchaea californica fire rhythmic bursts of action potentials during escape swimming behavior. We studied the role of the A1s in swimming behavior and pattern generation in whole animal and isolated CNS preparations. 2. The escape swim is a cyclic sequence of dorsal and ventral flexions of the body. During the swim, A1 bursts precede and accompany the dorsal flexion phase of the cycle. Hyperpolarization of A1 to prevent spike activity interrupts swimming behavior in the whole animal and fictive swimming in the isolated CNS. Stimulated A1 activity was not observed to cause swimming in whole animals, and was only occasionally sufficient to trigger fictive swimming activity in the isolated CNS. 3. In quiescent whole animal preparations, stimulation of a single A1 normally causes a single dorsal flexion followed by body flexion to the side contralateral to the stimulated cell; characteristically, A1 spike activity stimulates feedback inhibition coinciding with the end of dorsal flexion and the onset of contralateral flexion. 4. A1 spike activity suppresses feeding behavior and causes proboscis retraction in whole animal preparations induced to feed. A1 activity also suppresses fictive feeding driven by stimulation of the critical phasic paracerebral neurons (PCps) of the motor network of feeding in the isolated CNS. Concomitantly, A1 spikes cause potent inhibition of the PCp interneurons. 5. The A1s are specifically excited by noxious mechanical and chemical stimuli, but are not affected by feeding stimuli or the occurrence of feeding behavior. 6. We conclude that the A1 neurons are elements of an escape swimming pattern generator, and that they are probably homologous to the similar C2 neurons of the nudibranch Tritonia diomedea. One of their functions outside of generating the swim pattern may be the suppression of feeding behavior in response to noxious stimulation. These observations provide a neural mechanism for the original observations of the dominance of escape swimming behavior over feeding.     

Primary CNS lymphoma. Infratentorial localization and prolonged survival

A case of a 35-year-old woman presenting infratentorial CNS lymphoma is reported. In 1990 she complained of diplopia, blurred vision and left horizontal nistagmus. An MRI disclosed a lesion in the medulla, pons, and cerebellar vermis and peduncles. Although no treatment was administered, a later RMI showed less extension of the tumor. One year after clinical diagnosis, she received corticosteroids; during the second year a stereotaxic biopsy of the cerebellar lesion was done showing a diffuse B cell non-Hodgkin's lymphoma. A whole brain irradiation was given (50 Gy). She did well for five years, and remains alive (79 months).     

Immunohistochemical localization of enkephalin in peripheral sensory axons in the rat

Impaired energy metabolism plays an important role in neuronal cell death after brain ischemia, and apoptosis has been implicated in cell death induced by metabolic impairment. In the present study, metabolic impairment was induced by 3-nitropropionic acid (3-NP), an irreversible inhibitor of succinate dehydrogenase. In order to clarify the involvement of poly(ADP-ribosyl)ation and apoptotic pathway in 3-NP induced cell death, we examined poly(ADP-ribosyl)ation and the apoptosis related gene protein expression after systemic administration of 3-NP by immunohistochemistry. Poly(ADP-ribosyl)ation was evidently detected in the striatal lesion but not in any other region. Immunoreactive ratio of Bcl-2 to Bax significantly increased both in the striatum and cortex. The data suggest that striatal cell death involves poly(ADP-ribosyl)ation and also apoptotic pathway in part following administration of 3-NP.     

Sound localization in a predatory rodent, the northern grasshopper mouse (Onychomys leucogaster).

A comparison of the ability of mammals to localize sound revealed that among the animals examined to date, none of the rodents have been able to localize as accurately as the carnivores. Because all of these rodents are prey animals, the question arises as to whether their poor localization acuity is a phyletic trait of Rodentia or whether it is a trait common to prey species that may be under less selective pressure than predators to localize sound accurately. To answer this question, sound localization acuity was determined in a species that is both predatory and a rodent, the northern grasshopper mouse. Localization thresholds for a single 100-ms noise burst were determined for three grasshopper mice using a conditioned avoidance procedure. Their 50% discrimination threshold of 19° is larger than that of any of the previously tested carnivores and well within the range of other rodents. However, calculations of the binaural sound localization cues available to rodents (based on their head size) suggest that the grasshopper mouse may make more efficient use of the available locus cues than other rodents. Thus, although the grasshopper mouse cannot localize as accurately as carnivores, it appears to be more accurate than predicted for a nonpredatory rodent of its size. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immunohistochemical localization of peroxisomal enzymes in developing rat kidney tissues

We studied the developmental changes in the localization of peroxisome-specific enzymes in rat kidney tissues from embryonic Day 16 to postnatal Week 10 by immunoblot analysis and immunohistochemistry, using antibodies for the peroxisomal enzymes catalase, d-amino acid oxidase, l-alpha-hydroxyacid oxidase (isozyme B), and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase bifunctional protein. Peroxisomal enzymes were detected in the neonatal kidney by immunoblot analysis and their amount increased with kidney development. By light microscopic immunohistochemistry, they were first localized in a few proximal tubules in the juxtamedullary cortex of 18-day embryos. The distribution of proximal tubules positive for them expanded towards the superficial cortex with development. The full thickness of the cortex became positive for the staining by 14 days after birth. Peroxisomes could be detected by electron microscopy in structurally immature proximal tubules in 18-day embryos. Their size increased and the ultrastructure of subcompartments became clear with continuing development of proximal tubules. These results show that peroxisomal enzymes appear in the immature proximal tubules in the kidney of embryos and that the ultrastructure of the peroxisomes and localization of the peroxisomal enzymes develop along with the maturation of proximal tubules and kidney tissues.     

Expression and localization of membrane type 1 matrix metalloproteinase in tooth tissues

Matrix metalloproteinases (MMPs) have been detected in forming dental enamel and are thought to play an important role during enamel biomineralization. Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a membrane bound member of the MMP gene family that has previously been shown to be expressed by cells associated with bone and cartilage formation (osteoclasts, osteoblasts and chondrocytes). Thus, we asked if MT1-MMP was also expressed by the cells responsible for the formation of enamel and dentin. A porcine MT1-MMP cDNA composed of 3284 bp was isolated from an enamel organ-specific cDNA library. Multiple tissue Northern blot analysis revealed that the MT1-MMP message was expressed highly in the enamel organ and pulp organ when compared to the expression levels observed in other non-mineralizing tissues. Northern blot analysis of stage-specific enamel organs (early secretory, late secretory, or maturation stage) and their corresponding pulp organs revealed that MT1-MMP expression increased as the dentin matured. In the enamel organs, however, the MT1-MMP message level became reduced only during the late secretory stage. Immunohistochemical analysis showed that MT1-MMP was present on the surface of the cells (ameloblasts and odontoblasts) responsible for dentin and enamel formation. Thus, MT1-MMP is highly expressed in developing tooth tissues and may play a role in the biomineralization of enamel and dentin.     

PACAP and PACAP receptors in insulin producing tissues: localization and effects

Intracellular electrical recordings and fluorimetric measurement of intracellular Ca2+ concentration ([Ca2+]i) were made from enteric neurons of the guinea-pig myenteric and submucosal plexuses to examine the actions of 2-n-butyl-1-(4-methylpiperazinyl)5,6-ethylendioxyindene x 2HCl (TN-871) on neural activity in the single cell. TN-871 affected neuronal electrophysiological properties and synaptic transmission in the enteric nervous system in a concentration-dependent manner; TN-871 at lower concentrations hyperpolarized enteric neurons and/or facilitated synaptic transmission, whereas at higher concentrations it depolarized enteric neurons and/or inhibited synaptic transmission. Experiments with fura-2 showed that TN-871 modulated both resting [Ca2+]i and [Ca2+]i-transient associated with action potentials. Thus, the present results demonstrated that TN-871 at lower concentrations facilitates but at higher concentrations depresses Ca2+-dependent or Ca2+-involving processes, suggesting that TN-871 may affect the Ca2+ dynamics in enteric neurons either directly, indirectly or both.     

Subcellular localization of the K+ channel subunit Kv3.1b in selected rat CNS neurons

Voltage-gated potassium channels constitute the largest group of heteromeric ion channels discovered to date. Over 20 genes have been isolated, encoding different channel subunit proteins which form functional tetrameric K+ channels. We have analyzed the subcellular localization of subunit Kv3.1b, a member of the Kv3 (Shaw-like) subfamily, in rat brain at the light and electron microscopic level, using immunocytochemical detection. Detailed localization was carried out in specific neurons of the neocortex, hippocampus and cerebellum. The identity of Kv3.1b-positive neurons was established using double labeling with markers for specific neuronal populations. In the neocortex, the Kv3.1b subunit was expressed in most parvalbumin-containing bipolar, basket or chandelier cells, and in some bipolar or double bouquet neurons containing calbindin. In the hippocampus, Kv3.1b was expressed in many parvalbumin-containing basket cells, as well as in calbindin-positive neurons in the stratum oriens, and in a small number of interneurons that did not stain for either parvalbumin or calbindin. Kv3.1b protein was not present in pyramidal cells in the neocortex and the hippocampus, but these cells were outlined by labeled presynaptic terminals from interneuron axons that surround the postsynaptic cell. In the cerebellar cortex, granule cells were the only population expressing the channel protein. Careful examination of individual granule cells revealed a non-uniform distribution of Kv3.1 staining on the somata: circular bands of labeling were present in the vicinity of the axon hillock. In cortical and hippocampal interneurons, as well as in cerebellar granule cells, the Kv3.1b subunit was present in somatic and unmyelinated axonal membranes and adjacent cytoplasm, as well as in the most proximal portion of dendritic processes, but not throughout most of the dendrite. Labeling was also seen in the terminals of labeled axons, but not at a higher concentration than in other parts of the axon. The distribution in the cells analyzed supports a role in action potential transmission by regulating action potential duration.     

Kynurenic acid distribution into brain and peripheral tissues of mice

Kynurenic acid (KYN), an antagonist of excitatory amino acid receptors, is a putative antidote against neuroexcitatory amino acid toxicity. We studied various doses (0.05-3.17 mmol/kg, i.p.) and the effects of probenecid coadministration (0.70 mmol/kg, i.p.) on tissue distribution of KYN in male and female Swiss-Webster mice. After injection of [3H]KYN, samples of brain, heart, liver, kidney, skeletal muscle, and gut were collected at selected times and assayed for KYN by liquid scintillation counting. The substance was absorbed rapidly and distributed into all tissues. Its content (nmol/g, mean +/- SE) at 60 min was 0.26 +/- 0.05, 1.80 +/- 0.05, and 40.4 +/- 8.1 in brain (for 0.05, 0.53, and 3.17 mmol/kg), 1.43 +/- 0.11, 14.3 +/- 3.7, and 212 +/- 32 in heart, 1.16 +/- 0.21, 10.6 +/- 2.6, and 254 +/- 21 in liver, and 7.41 +/- 2.65, 180 +/- 63, and 1899 +/- 254 in kidney. Net accumulation of KYN in brain was much lower than in other tissues. Probenecid increased KYN concentration in brain 2.5-fold. Peak brain:blood concentration ratio occurred between 60 and 180 min, was inversely associated with dose, and was not affected by probenecid. Although brain content was similar, female mice had an earlier peak brain:blood ratio (120 min) than males (180 min) for the 0.05 mmol/kg dose. Our results suggest the presence of a restricted transfer process for KYN with delayed egress from brain.     

Immunohistochemical localization of chromogranin A in endocrine tissues and endocrine tumors of dogs

BACKGROUND: Research on health care quality and effectiveness often relies on global health status measures, such as functional status, but little is known about the functional status of patients in the primary care setting (without limitation to specific diseases) and even less about the function of the poor or ethnic minorities. In preparation for a planned practice-based research network, we administered a functional-status survey to patients visiting an inner-city family practice center. METHODS: Over 9 weeks, 555 established patients older than 18 years, as well as adolescents accompanied by a parent or guardian, completed a survey that included the SF-36 Health Survey and questions about demographic variables and cigarette use. The survey was self-administered in the waiting area and examination room, and patients received no assistance from staff. RESULTS: Functional-status scores reported by this primary care cohort were significantly lower than those of the general population (P < .001) and comparable with those reported nationally for patients with chronic diseases (e.g., congestive heart failure, diabetes). Functional-status scores were associated with age, sex, and, most strikingly, socioeconomic status. For example, patients with a yearly income of less than $15,000 had lower mean physical function scores than those reported nationally for patients with hypertension, diabetes, depression, recent myocardial infarction, or hypertension (P < .05). Patients who currently smoked reported lower physical function (P = .004) and strikingly lower mental function (P < .001) than nonsmokers. CONCLUSIONS: Although patients completing the survey included healthy persons seeking preventive care and sick patients with acute and chronic illnesses, their overall functional status resembled that reported nationally for patients with chronic disease, perhaps reflecting the influence of poverty. Few studies have reported the association we observed between smoking and lower functional status. Further longitudinal studies in the primary care setting are necessary to fully interpret these associations and to evaluate the true impact of interventions on outcomes.     

Immunochemical distribution and immunohistochemical localization of 20beta-hydroxysteroid dehydrogenase in neonatal pig tissues

Immunochemical distribution of 20beta-hydroxysteroid dehydrogenase (HSD) in neonatal pig tissues was investigated by Western blot analysis of the proteins reacting with anti-20beta-HSD antibody. 20beta-HSD was present in all organs investigated: brain, lung, thymus, submandibular gland, heart, liver, kidney, spleen, adrenal gland, testis, epididymis, prostate, vas deferens and seminal vesicle. In particular, high concentrations of 20beta-HSD were detected in the testis, followed by the kidney and liver, by the [125I]-protein A binding method. Immunohistochemical localization of the enzyme was achieved in paraffin sections of the testis, kidney, liver, epididymis, and vas deferens by the streptoavidin-biotin complex method. In the testis, very strong immunostaining was found only in interstitial Leydig cells, whereas the cells in seminiferous tubules, such as Sertoli cells and spermatogenic cells, were entirely negative. In the kidney, strong immunostaining was detected in epithelial cells of Henle's loop. The immunoreactive proteins were also localized in the hepatic lobules of the liver, tall columnar cells of the ductus epididymidis of the epididymis, and mucosal epithelium cells and muscularis of the vas deferens. These observations indicate that tissue distribution of 20beta-HSD is similar to that of carbonyl reductase in the human and rat. However, the specific and abundant expression of 20beta-HSD in testicular Leydig cells of the neonatal pig, which are concerned with the synthesis of androgens, suggests that 20beta-HSD has a very important physiological role in testicular function during the neonatal stage.     

Quantification of pericentral NADPH-diaphorase neurons in the spinal cord of rabbits

BACKGROUND: The freely diffusible radical nitric oxide is generated by nitric oxide synthase, and is bioregulatory molecule that functions as a major neurotransmitter. Constitutive nitric oxide synthase exhibits NADPH-diaphorase activity that can be demonstrated histochemically. OBJECTIVE: The purpose of the present investigation was to characterize and determine number of NADPH-diaphorase positive neurons around the central canal in all segments of the rabbit spinal cord. METHODS: Rabbits Chinchilla were used in this experiment. After intracardiac perfusion the spinal cords were removed, cut into slices and histochemical analysis of NADPH-diaphorase activity was performed. Sections were evaluated by using light microscope. RESULTS: NADPH-diaphorase positive pericentral neurons were present in cervical, thoracic, lumbar; sacral and coccygeal segments. They differed in the shape of their bodies and in length and branching of their processes. The main differentiation was observed in their number depending on the place of localisation. The highest number of these NADPH-diaphorase positive neurons was in sacral part (6 in average), the lowest one was noticeable in thoracic spinal cord (1-2 in average). CONCLUSION: Thus, our study suggests that pericentral neurons of the rabbit spinal cord which are capable of synthesizing nitric oxide, differs in number amount depending on the place of their localization in each spinal cord segments. (Tab. 2, Fig. 9, Ref. 21.)     

Characterisation of xenobiotic-metabolising enzyme expression in human bronchial mucosa and peripheral lung tissues

We examined the effects of amiodarone (AMI) and desethylamiodarone (DAM) on whole-cell inward rectifying potassium current (IK1) in freshly isolated adult rabbit ventricular myocytes by using the whole-cell voltage-clamp technique, as an index of their effects on resting membrane resistance (Rm). Under control conditions, the current showed a strong inward rectification with a maximal inward current measured at -130 mV of -26.4 +/- 1.3 pA/pF and a maximal outward current measured at -50 mV of 3.5 +/- 0.3 pA/pF The current also exhibit a time-dependent activation, with a time constant of activation (tau(a)) that increased with depolarization. The maximal slope conductance normalized to cell capacitance was 0.509 +/- 0.019 nS/pE After exposure to both DAM (50 microM; n = 8) and AMI (50 microM; n = 7), rapid decrease in inward IK1 was observed. Block was restricted almost exclusively to the inward component. DAM caused a significant reduction of the maximal inward current (-20.0 +/- 2.0 pA/pF; p < 0.05), whereas AMI induced an even greater reduction of the same component (-14.1 +/- 1.2 pA/pF; p < 0.05 with respect to control and to DAM). The outward component of IK1 was not changed by either AMI or DAM (4.0 +/- 0.3 pA/pF and 3.4 +/- 0.4 pA/pF, respectively). AMI and DAM also decreased the maximal slope conductance significantly (0.297 +/- 0.019 nS/pF and 0.421 +/- 0.038 nS/pF, respectively). In addition, AMI but not DAM significantly increased the tau(a). However, the voltage dependence of the acceleration of tau(a) remained unchanged after both AMI and DAM exposure. These results allow us to conclude that AMI may induce a greater increase in the resting Rm than its main metabolite. This effect may counterbalance, at least in part, the conduction slowing due to its sodium channel-blocking properties.     

Expression and localization of angiotensin II type 1 receptor mRNA in rat ocular tissues

OBJECTIVE: Hereditary hemorrhagic telangiectasia (HHT) is an inherited abnormality passed down as a dominant autosomal feature. Recurrent epistaxis usually constitutes the major clinical manifestation of this disease. The unsatisfactory results of conservative therapy have stimulated a research interest for the role of laser photocoagulation in telangiectatic vessels associated with this clinical entity. METHOD: The Nd:YAG laser was used to treat a group of 11 individuals suffering from HHT, all of whom had been previously treated using other modalities. RESULTS AND CONCLUSION: The excellent results of Nd:YAG laser irradiation are addressed in view of all treatment modalities proposed for the treatment of recurrent epistaxis in HHT.     

The NADPH-diaphorase activity of the bronchial epithelium in chronic lung diseases

Topochemistry and activity of NADP-H diaphorase co-localized with NO synthase was examined in operative material of lungs from patients with bronchial asthma (BA), chronic nonobstructive bronchitis (CNO) and chronic obstructive bronchitis. The enzyme activity was found to be dependent upon the types of obstruction and inflammation. In CNO the state of NO synthase was not changed. In conditions of progressive irreversible airway obstruction the enzyme activity was augmented in small bronchi epithelium and alveolar macrophages (AM). In reversible obstruction the activity of NO synthase was not changed in the epithelium but appeared high in resident cells of inflammation--AM and mast cells.     

An autoradiographic study on the localization of 131I-labeled thyroid hormones in the tissues of the pig

Autoradiographic studies on the localization of 131I-labeled thyroxine and triiodothyronine in the various organs and tissues of the pig have been conducted. The isotopes were compared as to the intensity of radioactivity on the basis of the concentration of developed silver grains in the tissues following the respective radioactive hormone injections. In general, for an identical dose of the isotope and with analogous processing procedures, the autoradiographs of most of the tissues after triiodothyronine were relatively more radioactive than after thyroxine. In both the hormone treatments, the tissues from younger pigs were relatively more radioactive than the tissues of older pigs. The various tissormones. Based on differential localization of radioactivity, the pigs excreted more radioiodine through bile, pancreatic and salivary secretions and in urine.