Meta-analysis of pre-clinical studies on the effects of opioid receptor ligands on food intake, motivation, and choice.

The opioid receptors (OR) regulate food intake. Still, despite extensive pre-clinical research, the overall effects and individual contribution of the mu (MOR), kappa (KOR), and delta (DOR) OR subtypes to feeding behaviors and food intake remain unclear. To address this, we conducted a pre-registered systematic search and meta-analysis of rodent dose-response studies to evaluate the impact of central and peripheral administration of non-selective and selective OR ligands on intake, motivation, and choice of food. All studies had a high bias risk. Still, the meta-analysis confirmed the overall orexigenic and anorexigenic effects of OR agonists and antagonists, respectively. Our results support a larger orexigenic role for central MOR agonists among OR subtypes and that peripheral OR antagonists reduce motivation for and intake of preferred foods. In binary food choice studies, peripheral OR agonists selectively increase the intake of fat-preferred foods; in contrast, they did not increase the intake of sweet carbohydrate-preferred foods. Overall, these data support that OR regulation of intake, motivation, and choice is influenced by food macronutrient composition.

Dataset for evaluating WRF-Chem sensitivity to biogenic emission inventories in a tropical region. Global online model (MEGAN) vs local offline model (BIGA).

This article presents a dataset comparing emissions of Biogenic Volatile Organic Compounds (BVOC) in a zone of complex topography in the tropical Andes, which presents elevations ranging from 250 to more than 4000 m above sea level in a radius of only 50 km. Two approximations were evaluated, (1) online with the Model of Emissions of Gases and Aerosols from Nature (MEGAN) coupled with the Weather Research and Forecast model with Chemistry (WRF-Chem) and (2) offline applying the Biogenic Altitudinal Gradient Model (BIGA). Modeled concentrations of pollutants (mainly isoprene and tropospheric ozone) were obtained with WRF-Chem employing the biogenic emission models mentioned previously. This information identified areas where BVOC emissions vary significantly, comparing the global emission inventory (MEGAN) and the local inventory (BIGA). Re-evaluation of the emission factors and land cover assigned to those areas in the global online biogenic models should be considered in order to reduce the uncertainty in the values. In addition, the dataset shows the impact of the biogenic emission inventories on the air quality simulations on a tropical high mountain area, where vegetation is diverse, and the altitudinal changes influence meteorological variables.

Apoptosis inhibition of Atlantic salmon (Salmo salar) peritoneal macrophages by Piscirickettsia salmonis.

To improve the understanding of the piscirickettsiosis pathogenesis, the in vivo apoptosis modulation of peritoneal macrophages and lymphocytes was studied in juvenile Salmo salar intraperitoneally injected with Piscirickettsia salmonis. Five fish were sampled at post-exposure days 1, 5, 8 (preclinical), 20 (clinical) and 40 (post-clinical period of the disease), and the leucocytes of their coelomic washings were analysed by flow cytometry (using the JC-1 cationic dye), TUNEL and cytology to detect apoptotic cells. A selective and temporal pattern of apoptosis modulation by P. salmonis infection was observed. Apoptosis in lymphocytes was not affected, whereas it was inhibited in macrophages but only during the preclinical stage of the induced piscirickettsiosis. Hence, it is postulated that P. salmonis inhibits macrophage apoptosis at the beginning of the disease development to survive, multiply and probably be transported inside these phagocytes; once this process is complete, macrophage apoptosis is no longer inhibited, thus facilitating the exit of the bacteria from the infected cells for continuing their life cycle.

Neurotrophin-dependent plasticity of neurotransmitter segregation in the rat superior cervical ganglion in vivo.

Neurons are able to segregate transmitters to different axon endings. Segregation is a plastic neuronal feature; it can be modulated by synaptic environment. We have demonstrated that neurotrophin and other cellular factors regulate segregation in sympathetic neurons in culture. Herein we tested the hypothesis that sympathetic neurons in vivo are also capable to exhibit neurotrophin-dependent plasticity of segregation. To explore the effect of neurotrophin on segregation, we reduced ganglionic NGF content by the transection of postganglionic nerves (axotomy) of the superior cervical ganglia. By immunohistochemistry, Western blot, and PCR analyses, we explored the effect of axotomy on the NGF and BDNF content of ganglionic neurons, and on the segregation extent of vesicular acetylcholine transporter (VAChT) and methionine enkephalin (mENK) in pre-ganglionic varicosities. We analyzed NGF-dependence of the changes found by applying exogenous NGF. Axotomy reduced ganglionic NGF and BDNF content, increased NGF transcripts, and increased VAChT-mENK segregation. Axotomy also increased the number of VAChT immunopositive varicosities, and caused the appearance of a population of VAChT-, mENK- or SV2-containing varicosities lacking Synaptophysin (Syn). Administration of NGF prevented changes in NGF content, kept NGF transcripts increased, and counteracted changes in segregation and in the number of cholinergic varicosities. The exogenous NGF did not preclude change in BDNF content or in the occurrence of the VAChT- or mENK-containing varicosities lacking Syn. Data demonstrate that segregation of transmitters in vivo is plastic and it is modulated by environmental signals like NGF. We propose a possible functional correlate of segregation plasticity in the sympathetic ganglia. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 832-846, 2016.

Nasal Cavity Masses Resembling Chondro-osseous Respiratory Epithelial Adenomatoid Hamartomas in 3 Dogs.

Chondro-osseous respiratory epithelial adenomatoid hamartomas (COREAHs) are rare tumors in the nasal cavity of people, which have not been described in other species. COREAHs in people are minimally invasive and rarely recur following excision. Histologically, these tumors are composed of disorganized, mature, nasal turbinate tissue that is organized into polypoid growths. These growths are lined by respiratory epithelium, contain glandular elements, and are organized around central cores of chondro-osseous matrix. This report describes 3 cases of dogs with nasal tumors that have histomorphology similar to that of COREAH in people. The tumors were all identified within the nasal cavity and were associated with regional bony lysis of the turbinates and surrounding skull bones, a feature that has not been reported in COREAH in people. There was no evidence of metastasis or extension beyond the nasal cavity in any of the 3 cases.

Long-term potentiation in mammalian autonomic ganglia: an inclusive proposal of a calcium-dependent, trans-synaptic process.

Ganglionic synapses have the capability to express long-term potentiation (gLTP) after application of a brief high-frequency stimulus. It has been suggested a possible role of gLTP in some cardiovascular diseases. Although a number of characteristics of gLTP have been described, the precise locations and mechanisms underlying gLTP are not completely known. Current findings support two major conflicting presynaptic and postsynaptic hypotheses. The presynaptic hypothesis posits a presynaptic increase in acetylcholine (ACh) release, whereas the postsynaptic hypothesis proposes a long-lasting enhancement of the nicotinic response on the postsynaptic membrane. An alternative trans-synaptic hypothesis proposes the presynaptic release of a cotransmitter from large dense core vesicles, which postsynaptically enhances synaptic efficacy and accounts for gLTP. Here, we review the studies of LTP, with emphasis on gLTP in mammals, and we examine the findings that support the presynaptic, the postsynaptic and the trans-synaptic hypotheses. We then review our data on the contribution of calcium to gLTP as an approach to elucidate the mechanisms of gLTP. Data on the contribution of calcium to gLTP and on prolonged high-frequency stimulus-dependent fading of LTP have led us to support the trans-synaptic process as responsible for gLTP. Finally, we present a formal working model for the mechanisms of gLTP.

Review: Differential placental macrovascular and microvascular endothelial dysfunction in gestational diabetes.

Human endothelial dysfunction is a common feature in many diseases of pregnancy, such as gestational diabetes (GD). Metabolic changes include abnormal synthesis of nitric oxide (NO) and abnormal membrane transport of l-arginine and adenosine in primary cultures of human umbilical vein (HUVEC, macrovascular) and placental microvillus (hPMEC, microvascular) endothelial cells. These alterations are associated with modifications in the expression and activity of endothelial (eNOS) and inducible (iNOS) NO synthases, respectively, an effect that is maintained at least up to passage 5 in culture. HUVEC and hPMEC exhibit expression and activity of the human cationic amino acid transporter 1 (hCAT-1), equilibrative nucleoside transporters 1 (hENT1) and hENT2, as well as the corresponding SLC7A1, SLC29A1 and SLC29A2 gene promoter activities. Altered gene expression results from increased NO level, protein kinase C, mitogen-activated protein kinases, and hCHOP-C/EBPα transcription factor activation. Reduced ENT-mediated adenosine transport in GD is associated with stimulation of the l-arginine/NO pathway, and mainly due to reduced expression and activity of hENT1. In addition, hENT2 activity seems able to restore the reduced adenosine transport in GD. Additionally, insulin exerts a differential modulation of endothelial cells from macrocirculation compared with microcirculation, possibly due to expression of different insulin receptor isoforms. It is suggested that a common functional characteristic leading to changes in the bioavailability of adenosine and metabolism of l-arginine is evidenced by human fetal micro and macrovascular endothelium in GD.

Role of presynaptic and postsynaptic IP3-dependent intracellular calcium release in long-term potentiation in sympathetic ganglion of the rat.

In the rat superior cervical ganglion, a form of long term potentiation (LTP) can be elicited by a brief high frequency stimuli applied to the preganglionic nerve. Cumulative evidence shows that a transient increase in cytoplasmic Ca²+ concentration is essential for the generation of the ganglionic LTP. Calcium influx and calcium release from intracellular calcium stores contribute to LTP. However, the differential role of presynaptic and postsynaptic calcium signaling has not been established. Herein, by using heparin, a membrane-impermeant inositol trisphosphate receptor (IP3R) blocker, we explored the contribution of presynaptic and postsynaptic IP3-sensitive calcium stores to the ganglionic LTP. The LTP was produced by a conditioning train of 40 Hz for 3 s. We analyzed the effects of heparin on the posttetanic potentiation: PTP magnitude and PTP time constant, and on two parameters that describe the LTP: LTP decay time (elapsed time required by the potentiated response to fall to 20% above the basal value) and LTP extent (the integral of the potentiated response). Heparin (100 and 200 µg/ml) was loaded in the preganglionic, the postganglionic, or in both nerves. We found that in all tested conditions heparin significantly decreased LTP but practically did not affect PTP. The preganglionic and postganglionic inhibitory effects of heparin were not additive. De-N-sulfated heparin, an ineffective IP3R blocker, had no effect on LTP, but abolished the heparin blocking effect. Data suggest that presynaptic and postsynaptic IP3-dependent intracellular calcium release equally contribute to ganglionic LTP, supporting our proposal of a trans-synaptic mechanism for LTP.

Densidad neuronal en la corteza visual primaria (área 17), en ratas sometidas a estrés crónico / Density in primary visual cortex (17 visual area) from rats subjected to chronic stress

El estrés puede ser definido como una amenaza a la integridad psicológica o fisiológica de un individuo. Por otro lado, se ha verificado que el estrés tiene efecto sobre la morfología y función de diversas estructuras del Sistema Nervioso Central, relacionadas con el aprendizaje, memoria y respuestas emocionales, tales como el hipocampo, amígdala y corteza prefrontal. Es por lo anterior, que el objetivo del presente trabajo fue realizar un estudio de la anatomía de la corteza visual primaria (área 17), en ratas machos (n=9), de la cepa Sprague-Dawley, de 3 meses de edad (250-350g.), sometidas a estrés crónico por inmovilización. Es así como se observó que el grupo estrés (n=3) presentó una menor densidad neuronal que el grupo control (n=3) y una significativa menor densidad neuronal (p<0,05) que el grupo post estrés (n=3) el cual presentó la más alta densidad neuronal observada. Estableciendo una relación inversa entre densidad neuronal y tamaño de los somas neuronales y sus respectivas conexiones y ramificaciones dendríticas. Lo anterior podría tener incidencia en el procesamiento de la información visual.

Stress can be understood as a threat to psychological or physiological integrity of the individual. Stress has previously shown to alter morphology and function of diverse structures of the Central Nervous System related to learning, memory and emotional response, such as hippocampus, amygdala and prefrontal cortex. In the current work we assessed the effect of chronic stress for immobilization on structure of primary visual cortex (area 17) in male adult Sprague-Dawley rats (n=9), of 3 months of age (250-350g.). Stressed rats (n=3) tended to show lower neuronal densities than control rats (n=3) and were significantly lower (p<0.05) than recovered post-stress rats (n=3), which showed the highest neuronal densities observed. Since an inverse correlation between neuronal density and size of neuronal bodies and their respective dendrite branches, these changes might impact processing of visual information.

Segregation of met-enkephalin from vesicular acetylcholine transporter and choline acetyltransferase in sympathetic preganglionic varicosities mostly lacking synaptophysin and synaptotagmin.

Sympathetic preganglionic neurons (SPN) coexpress the acetylcholine (ACh)-synthesizing enzyme choline acetyltransferase and different peptides in their cell bodies, but can express them independently in separate varicosities, indicating that SPN segregate transmitters to different synapses. Consequently, there are populations of preganglionic varicosities (peptidergic and noncholinergic) that store peptides but not ACh. We studied in the cell bodies and axon processes of the rat SPN the expression and the proportional coexpression of the vesicular ACh transporter-like immunoreactivity (VAChT), a specific marker of cholinergic synaptic vesicles or ChAT-like immunoreactivity (ChAT), and the peptide methionine enkephalin-like immunoreactivity (mENK), and confirmed the presence of a population of SPN peptidergic, noncholinergic varicosities. We characterized these varicosities by exploring the occurrence of synaptophysin-like immunoreactivity (Syn), a marker of small clear vesicles, and synaptotagmin-like immunoreactivity (Syt), a preferential marker of large dense core vesicles. We found that (i) VAChT and mENK, like ChAT-mENK, were coexpressed in only 59% of the mENK-containing varicosities, although they colocalized in the SPN cell bodies; and (ii) almost 60% of the population of mENK-containing varicosities did not express Syn or Syt, and over 80% of the mENK-containing varicosities negative for VAChT also lacked Syn. These data prove that SPN segregate mENK from VAChT and ChAT, and show that most of the subset of mENKergic varicosities negative for VAChT also does not express Syn, suggesting the presence of a different vesicular pattern in these sympathetic preganglionic varicosities.

Relación entre consumo de fármacose hipopotasemia en atención primaria / No disponible

Objetivo. Describir la relación entre la hipopotasemia y el consumo de fármacos en el ámbito de la atenciónprimaria. Material y métodos. Estudio descriptivo retrospectivo realizado en el conjunto del área de saludde Albacete sobre el año 2007. Se recogió información sobre los niveles de potasio sérico (Hospital General deAlbacete), la prescripción farmacéutica (Digitalis) y datos demográficos (Turriano) de los pacientes seleccionados.Los datos fueron codificados, depurados y analizados mediante el programa estadístico SPSS(versión 13.0), y se realizó un análisis descriptivo y un análisis estadístico (prueba de la t de Student yprueba de la ji al cuadrado). Resultados. Se encontraron 310 pacientes con el potasio plasmático disminuidodurante el periodo de estudio, de los que 231 habían consumido algún fármaco capaz de producir hipopotasemia.Los grupos de fármacos más consumidos por los pacientes fueron los diuréticos no ahorradores depotasio (63,9% del total de pacientes), los beta-2-agonistas (13,2%), los laxantes (13,2%) y los alfa-antagonistas(9%). Conclusiones. Dado que consideramos la hipopotasemia como una condición clínica que puede tenerrepercusiones graves y dado que los grupos farmacológicos mencionados se prescriben ampliamente en atenciónprimaria, creemos que convendría hacer determinaciones periódicas de los niveles de potasio a lospacientes que toman este tipo de medicamentos, para evitar de este modo las complicaciones asociadas a laaparición de hipopotasemia severa o grave (AU)

Objective. to describe the relationship between hypokalemia and the consumption of drugs in the field ofprimary care. Material and Method. retrospective descriptive study in the year 2007 in the ensemble ofHealth Care Services of Albacete. The data regarding the levels of serum potassium (H.G. Albacete), pharmaceuticalprescriptions (Digitalis) and the demographic data (Turriano) of the selected patients was collected.The data was codified, refined and analysed with SPSS v13.0: descriptive analysis and statistical analysis:Student’s t test and Chi-square test. Results. during the period of the study decreased plasma potassium wasfound in 310 patients, 231 of whom had taken some kind of drug capable of producing hypokalemia. The druggroups most consumed in this type of patients were non-potassium-sparing diuretics (63.9% of the totalpatients), beta-2-agonists (13.2%), laxatives (13.2%) and alfa-antagonists (9%). Conclusions. consideringhypokalemia as a clinical condition that could have serious repercussions, and given that these groups ofmedicines are broadly prescribed in Primary Care, we consider it appropriate for the levels of potassium inpatients who consume this type of medication to be monitored periodically, in order to avoid complicationsassociated with the onset of severe or serious hypokalemia (AU)

Osteomielitis crónica esclerosante difusa / Chronic diffuse sclerosing osteomyelitis

La osteomielitis esclerosante difusa se considera como una osteomielitis crónica primaria consistente en un proceso inflamatorio, doloroso y prolongado en el tiempo. Afecta solo a la mandíbula y es generalmente unilateral, compromete hueso basal y alveolar, y se localiza al nivel de cuerpo, ángulo, rama e incluso cóndilo. La causa es aún controversial, ya que algunos le atribuyen un origen infeccioso, mientras otros lo consideran una condición no infecciosa, como producto de sobrecargas o asociado con síndrome SAPHO (sinovitis, acné, pustulosis, hiperostosis y osteítis), pero la literatura no es concluyente. Con respecto al tratamiento, al igual que su causa, no está totalmente esclarecido y se describen a lo largo del tiempo distintas alternativas, que van desde lo conservador a lo más radical. Se presenta el seguimiento y tratamiento durante 7 meses de una paciente afectada por osteomielitis esclerosante difusa con 18 años de evolución aproximadamente, que ha sido refractaria a las alternativas terapéuticas convencionales(AU)

Diffuse sclerosing osteomyelitis is considered a chronic primary osteomyelitis consisting in an inflammatory, painful and prolonged process. It only affects the mandible and it is generally unilateral. It involves the basal and alveolar bone and it is located at the level of body, angle, branch and even condyle. The cause is more controversial, since some attribute an infectious origin to it, whereas others consider it as a non-infectious condition resulting from the overloads or associated with SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis and osteitis), but literature is not concluding. Treatment as well as its cause are not totally clear. Different alternatives are described that go from the conservative to the most radical position. The 7-month follow-up and treatment of a female patient suffering from diffuse sclerosing osteomyelitis with approximately18 years of evolution that has been refractory to the conventional therapeutic alternatives is presented(AU)

High-frequency stimuli preferentially release large dense-core vesicles located in the proximity of nonspecialized zones of the presynaptic membrane in sympathetic ganglia.

We characterized the effect of a brief high-frequency stimulus on the number, distribution, and optical density of large dense-core vesicles (LDCVs) in the nerve terminals of the rat superior cervical ganglia. From 4.21+/-0.37 LDCVs/bouton detected in control nerve terminals, a stimulus of 40 Hz for 1 min released 41% of LDCVs, decreasing their number to 2.48+/-0.14 LDCVs/bouton (p=0.0009). In control ganglia, most dense vesicles were located close to the plasma membrane (at

Cryptic deletions are a common finding in "balanced" reciprocal and complex chromosome rearrangements: a study of 59 patients.

Using array comparative genome hybridisation (CGH) 41 de novo reciprocal translocations and 18 de novo complex chromosome rearrangements (CCRs) were screened. All cases had been interpreted as "balanced" by conventional cytogenetics. In all, 27 cases of reciprocal translocations were detected in patients with an abnormal phenotype, and after array CGH analysis, 11 were found to be unbalanced. Thus 40% (11 of 27) of patients with a "chromosomal phenotype" and an apparently balanced translocation were in fact unbalanced, and 18% (5 of 27) of the reciprocal translocations were instead complex rearrangements with >3 breakpoints. Fourteen fetuses with de novo, apparently balanced translocations, all but two with normal ultrasound findings, were also analysed and all were found to be normal using array CGH. Thirteen CCRs were detected in patients with abnormal phenotypes, two in women who had experienced repeated spontaneous abortions and three in fetuses. Sixteen patients were found to have unbalanced mutations, with up to 4 deletions. These results suggest that genome-wide array CGH may be advisable in all carriers of "balanced" CCRs. The parental origin of the deletions was investigated in 5 reciprocal translocations and 11 CCRs; all were found to be paternal. Using customized platforms in seven cases of CCRs, the deletion breakpoints were narrowed down to regions of a few hundred base pairs in length. No susceptibility motifs were associated with the imbalances. These results show that the phenotypic abnormalities of apparently balanced de novo CCRs are mainly due to cryptic deletions and that spermatogenesis is more prone to generate multiple chaotic chromosome imbalances and reciprocal translocations than oogenesis.

Molecular heterogeneity in chronic lymphocytic leukemia is dependent on BCR signaling: clinical correlation.

Chronic lymphocytic leukemia (CLL), the most frequent form of adult leukemia in Western countries, is characterized by a highly variable clinical course. Expression profiling of a series of 160 CLL patients allowed interrogating the genes presumably playing a role in pathogenesis, relating the expression of functionally relevant signatures with the time to treatment. First, we identified genes relevant to the biology and prognosis of CLL to build a CLL disease-specific oligonucleotide microarray. Second, we hybridized a training series on the CLL-specific chip, generating a biology-based predictive model. Finally, this model was validated in a new CLL series. Clinical variability in CLL is related with the expression of two gene clusters, associated with B-cell receptor (BCR) signaling and mitogen-activated protein kinase (MAPK) activation, including nuclear factor-kappaB1 (NF-kappaB1). The expression of these clusters identifies three risk-score groups with treatment-free survival probabilities at 5 years of 83, 50 and 17%. This molecular predictor can be applied to early clinical stages of CLL. This signature is related to immunoglobulin variable region somatic hypermutation and surrogate markers. There is a molecular heterogeneity in CLL, dependent on the expression of genes defining BCR and MAPK/NF-kappaB clusters, which can be used to predict time to treatment in early clinical stages.

Differential contribution of extracellular and intracellular calcium sources to basal transmission and long-term potentiation in the sympathetic ganglion of the rat.

Calcium involved in basal ganglionic transmission and long-term potentiation (LTP) can arise either by influx from the extracellular medium or release from intracellular stores. No attempts have yet been made to concurrently explore the contributions of extracellular and intracellular Ca2+ to basal ganglionic transmission or LTP. Here, we investigate this subject using the superior cervical ganglion of the rat. To explore the extracellular Ca2+ contribution, we evaluated basal transmission and LTP at different extracellular Ca2+ concentrations. To assess intracellular Ca2+ release, we explored the contribution of the calcium-induced calcium release process by overactivation or blockade of ryanodine-sensitive Ca2+ receptor channel with caffeine, and also by blocking either IP3R with Xestospongin C or the sarco(endo)plasmic reticulum Ca2+-ATPase pump with thapsigargin. Extracellular Ca2+ affected ganglionic basal transmission and LTP to different extents. While 25% of the physiological Ca2+ concentration supported 80% of basal transmission, 50% of normal Ca2+ was required to achieve 80% of LTP. Notably, disruption of intracellular Ca2+ release by all the drugs tested apparently did not affect basal ganglionic transmission but impaired LTP. We conclude that basal transmission requires only a small level of Ca2+ entry, while LTP expression not only requires more Ca2+ entry but is also dependent on Ca2+ release from intracellular stores.

DNA profiling analysis of 100 consecutive de novo acute myeloid leukemia cases reveals patterns of genomic instability that affect all cytogenetic risk groups.

We have carried out a high-resolution whole genome DNA profiling analysis on 100 bone marrow samples from a consecutive series of de novo acute myeloid leukemia (AML) cases. After discarding copy number changes that are known to be genetic polymorphisms, we found that genomic aberrations (GA) in the form of gains or losses of genetic material were present in 74% of the samples, with a median of 2 GA per case (range 0-35). In addition to the cytogenetically detected aberration, GA were present in cases from all cytogenetic prognostic groups: 79% in the favorable group, 60% in the intermediate group (including 59% of cases with normal karyotype) and 83% in the adverse group. Five aberrant deleted regions were recurrently associated with cases with a highly aberrant genome (e.g., a 1.5 Mb deletion at 17q11.2 and a 750 kb deletion at 5q31.1). Different degrees of genomic instability showed a statistically significant impact on survival curves, even within the normal karyotype cases. This association was independent of other clinical and genetic parameters. Our study provides, for the first time, a detailed picture of the nature and frequency of DNA copy number aberrations in de novo AML.

Choline acetyl transferase and neuropeptide immunoreactivities are colocalized in somata, but preferentially localized in distinct axon fibers and boutons of cat sympathetic preganglionic neurons.

Cholinergic sympathetic preganglionic neurons (SPN) coexpress the biosynthetic enzyme for acetylcholine, choline acetyl-transferase (ChAT), and neuropeptides such as enkephalin (ENK) in their cell bodies. However, it is not clear whether they also coexpress ChAT and neuropeptides in axon fibers and boutons. To explore coexpression of ChAT and neuropeptides in somata and axon processes of SPN, we investigated, using immunohistochemistry, retrograde labeling, confocal analysis, and tridimensional reconstruction, whether ChAT and the peptides neurotensin, methionine-ENK, somatostatin, calcitonin gene-related peptide, and vasoactive intestinal peptide colocalize in somata, axons fibers, and boutons of cat SPN. Practically, complete colocalization for these peptides and ChAT was observed in SPN somata. Conversely, in most instances we observed independent localization of immunoreactivity (IR) for ChAT and the peptides in axon fibers and boutons. The minor colocalization between ChAT- and peptide-IR in preganglionic fibers could correspond to a sequential axonal transport of ChAT and peptides, since we observed coexistence of these transmitters after blocking axonal transport. Contrary to Dale's principle, our results suggest that SPN can synthesize ChAT and peptides in their cell bodies and route them to distinct axon boutons or terminals in sympathetic ganglia. Presence of axon boutons containing either ChAT or neuropeptides lead us to suggest a new neurochemical pattern of cotransmission in sympathetic ganglia based on the concurrent release of transmitters and cotransmitters from distinct presynaptic boutons, rather than in the corelease of these mediators from the same axon process. The possibility that cellular segregation could be transient and depend on functional requirements is considered.

Contribution of different calcium channels to long-term potentiation in superior cervical ganglion of the rat.

We explored the contribution of different calcium channel types to the long-term potentiation (LTP) of superior cervical ganglion of the rat. Right after a conditioning train of 40 Hz for 5 s, the maximum amplitude of the postsynaptic response (maximum potentiation) increased 5.6+/-0.5-fold. Potentiation decreased to 20% of its initial value within the following 70.0+/-8.0 min (LTP decay time). The contribution of P/Q-, N- and L-type calcium channels to LTP was studied by blocking their activity with synthetic funnel-web spider toxin (10 or 100 microM), omega-conotoxin GVIA (5 microM) or nifedipine (10 microM), respectively. The three blockers reduced the amplitude of the postsynaptic compound action potential before the conditioning train. After the train, all of the toxins reduced the LTP decay time and the integral of the amplitude versus time curve, defined as the LTP extent. In addition, all three blockers increased the maximum potentiation. Our results demonstrate that different calcium channel types contribute to ganglionic LTP. These effects may be by coupling excitation-secretion from different types of synaptic vesicles.

A ryanodine fluorescent derivative reveals the presence of high-affinity ryanodine binding sites in the Golgi complex of rat sympathetic neurons, with possible functional roles in intracellular Ca(2+) signaling.

The plant alkaloid ryanodine (Ry) is a high-affinity modulator of ryanodine receptor (RyR) Ca(2+) release channels. Although these channels are present in a variety of cell types, their functional role in nerve cells is still puzzling. Here, a monosubstituted fluorescent Ry analogue, B-FL-X Ry, was used to reveal the distribution of RyRs in cultured rat sympathetic neurons. B-FL-X Ry competitively inhibited the binding of [3H]Ry to rabbit skeletal muscle SR membranes, with an IC(50) of 150 nM, compared to 7 nM of unlabeled Ry. Binding of B-FL-X Ry to the cytoplasm of sympathetic neurons is saturable, reversible and of high affinity. The pharmacology of B-FL-X Ry showed marked differences with unlabeled Ry, which are partially explained by its lower affinity: (1) use-dependent reversible inhibition of caffeine-induced intracellular Ca(2+) release; (2) diminished voltage-gated Ca(2+) influx, due to a positive shift in the activation of voltage gated Ca(2+) currents. B-FL-X Ry-stained sympathetic neurons, viewed under confocal microscopy, showed conspicuous labeling of crescent-shaped structures pertaining to the Golgi complex, a conclusion supported by experiments showing co-localization with Golgi-specific fluorescent probes and the breaking up of crescent-shaped staining after treatment with drugs that disassemble Golgi complex. The presence of RyRs to the Golgi could be confirmed with specific anti-RyR(2) antibodies, but evidence of caffeine-induced Ca(2+) release from this organelle could not be obtained using fast confocal microscopy. Rather, an apparent decrease of the cytosolic Ca(2+) signal was detected close to this organelle. In spite of that, short-term incubation with brefeldin A (BFA) suppressed the fast component of caffeine-induced Ca(2+) release, and the Ca(2+) release process lasted longer and appeared less organized. These observations, which suggest a possible role of the Golgi complex in Ca(2+) homeostasis and signaling in nerve cells, could be relevant to reports involving derangement of the Golgi complex as a probable cause of some forms of progressive neuronal degeneration, such as Alzheimer's disease and amyotrophic lateral sclerosis.