Association of GA genotype of SNP rs4680 in COMT gene with psoriasis

Psoriasis is a multigene and multifactorial skin disease with heterogeneous genetic inheritance. Mental disorders participate in the development of psoriasis as predisposing factors; a correlation of dermatological diseases with pathological anxiety and stress was shown. Meanwhile, there are no studies describing molecular mechanisms of the linkages between psycho-emotional disorders and skin diseases. The aim of this study is to find the associations between SNP in genes COMT (rs4680), DBH (rs141116007), CCKAR (rs1800857) and CCKBR (rs1805002), and psoriasis. Patients were selected according to the 10th revision of International Classification of Diseases (L-40). The sample size was 88 patients. The size of the control sample (population control) was 365 people. Genotyping was performed using PCR-RFLP and real-time PCR. Statistical analysis was performed using WinPepi software. Identification of complex genotypes was performed by the Monte Carlo method using APSampler 3.6.1 algorithm. Among the studied genes, only GA genotype of COMT gene is significantly associated with psoriasis [χ² = 19.163 (p = 1.3E-5), F (p) = 1.2E-5, OR 3.47 (CI 99% = 1.61-7.91)]. At the moment, the functional significance of this phenomenon is difficult to explain.

Involvement of dopamine beta-hydroxylase in the neuroendocrine-immune regulatory network of white shrimp, Litopenaeus vannamei

In shrimp, the biosynthesis of catecholamines, including dopamine and norepinephrine, is required for physiological and immunological responses against stress. Dopamine beta-hydroxylase (DBH), a copper-containing monooxygenase enzyme that plays an important role in catecholamine synthesis of the neuroendocrine regulatory network, was identified in Litopenaeus vannamei. In the present study, the potential role of DBH in the immunocompetence of L. vannamei was further estimated by depleting DBH by pharmaceutical inhibition of disulfiram and a gene silencing technique of L. vannamei DBH-double-stranded (ds)RNA (LvDBH-dsRNA). Immunocompetence was evaluated following the determination of the total hemocyte count, differential hemocyte count, phenoloxidase activity, respiratory bursts, superoxide dismutase activity, phagocytic activity, and the clearance efficiency as well as the susceptibility against Vibrio alginolyticus infection. At 30-120 min after shrimp had received disulfiram, they exhibited significantly reduced total hemocyte count, phenoloxidase activity of hemocytes in hemolymph, respiratory bursts of hemocytes in hemolymph and per hemocyte, phagocytic activity, clearance efficiency, and survival ratio against V. alginolyticus infection, compared to those injected with saline. In addition, the significantly lower total hemocyte count, phagocytic activity, clearance efficiency, and resistance to V. alginolyticus infection were observed in shrimp that received LvDBH-dsRNA at 3 days post injection compared to those injected with diethyl pyrocarbonate-water or non-targeting gene-dsRNA. The DBH depleted L. vannamei revealed immunosuppression and decreased the survival ratio to V. alginolyticus infection, which indicated that DBH played a crucial role in the neuroendocrine-immune regulatory network.

Identification of Candidate Tolerogenic CD8(+) T Cell Epitopes for Therapy of Type 1 Diabetes in the NOD Mouse Model

Type 1 diabetes is an autoimmune disease in which insulin-producing pancreatic islet β cells are the target of self-reactive B and T cells. T cells reactive with epitopes derived from insulin and/or IGRP are critical for the initiation and maintenance of disease, but T cells reactive with other islet antigens likely have an essential role in disease progression. We sought to identify candidate CD8(+) T cell epitopes that are pathogenic in type 1 diabetes. Proteins that elicit autoantibodies in human type 1 diabetes were analyzed by predictive algorithms for candidate epitopes. Using several different tolerizing regimes using synthetic peptides, two new predicted tolerogenic CD8(+) T cell epitopes were identified in the murine homolog of the major human islet autoantigen zinc transporter ZnT8 (aa 158-166 and 282-290) and one in a non-β cell protein, dopamine β-hydroxylase (aa 233-241). Tolerizing vaccination of NOD mice with a cDNA plasmid expressing full-length proinsulin prevented diabetes, whereas plasmids encoding ZnT8 and DβH did not. However, tolerizing vaccination of NOD mice with the proinsulin plasmid in combination with plasmids expressing ZnT8 and DβH decreased insulitis and enhanced prevention of disease compared to vaccination with the plasmid encoding proinsulin alone.

The rate of fall of blood glucose determines the necessity of forebrain-projecting catecholaminergic neurons for male rat sympathoadrenal responses

Different onset rates of insulin-induced hypoglycemia use distinct glucosensors to activate sympathoadrenal counterregulatory responses (CRRs). Glucosensory elements in the portal-mesenteric veins are dispensable with faster rates when brain elements predominate, but are essential for responses to the slower-onset hypoglycemia that is common with insulin therapy. Whether a similar rate-associated divergence exists within more expansive brain networks is unknown. Hindbrain catecholamine neurons distribute glycemia-related information throughout the forebrain. We tested in male rats whether catecholaminergic neurons that project to the medial and ventromedial hypothalamus are required for sympathoadrenal CRRs to rapid- and slow-onset hypoglycemia and whether these neurons are differentially engaged as onset rates change. Using a catecholamine-specific neurotoxin and hyperinsulinemic-hypoglycemic clamps, we found that sympathoadrenal CRRs to slow- but not rapid-onset hypoglycemia require hypothalamus-projecting catecholaminergic neurons, the majority of which originate in the ventrolateral medulla. As determined with Fos, these neurons are differentially activated by the two onset rates. We conclude that 1) catecholaminergic projections to the hypothalamus provide essential information for activating sympathoadrenal CRRs to slow- but not rapid-onset hypoglycemia, 2) hypoglycemia onset rates have a major impact on the hypothalamic mechanisms that enable sympathoadrenal CRRs, and 3) hypoglycemia-related sensory information activates hindbrain catecholaminergic neurons in a rate-dependent manner.

Hindbrain noradrenergic input to the hypothalamic PVN mediates the activation of oxytocinergic neurons induced by the satiety factor oleoylethanolamide

Oleoylethanolamide (OEA) is a gut-derived endogenous lipid that stimulates vagal fibers to induce satiety. Our previous work has shown that peripherally administered OEA activates c-fos transcription in the nucleus of the solitary tract (NST) and in the paraventricular nucleus (PVN), where it enhances oxytocin (OXY) expression. The anorexigenic action of OEA is prevented by the intracerebroventricular administration of a selective OXY receptor antagonist, suggesting a necessary role of OXYergic mediation of OEA's effect. The NST is the source of direct noradrenergic afferent input to hypothalamic OXY neurons, and therefore, we hypothesized that the activation of this pathway might mediate OEA effects on PVN neurons. To test this hypothesis, we subjected rats to intra-PVN administration of the toxin saporin (DSAP) conjugated to an antibody against dopamine-β-hydroxylase (DBH) to destroy hindbrain noradrenergic neurons. In these rats we evaluated the effects of OEA (10 mg/kg, ip) on feeding behavior, on c-Fos and OXY immunoreactivity in the PVN, and on OXY immunoreactivity in the posterior pituitary gland. We found that the DSAP lesion completely prevented OEA's effects on food intake, on Fos and OXY expression in the PVN, and on OXY immunoreactivity of the posterior pituitary gland; all effects were maintained in sham-operated rats. These results support the hypothesis that noradrenergic NST-PVN projections are involved in the activation of the hypothalamic OXY system, which mediates OEA's prosatiety action.

Ascending caudal medullary catecholamine pathways drive sickness-induced deficits in exploratory behavior: brain substrates for fatigue?

Immune challenges can lead to marked behavioral changes, including fatigue, reduced social interest, anorexia, and somnolence, but the precise neuronal mechanisms that underlie sickness behavior remain elusive. Part of the neurocircuitry influencing behavior associated with illness likely includes viscerosensory nuclei located in the caudal brainstem, based on findings that inactivation of the dorsal vagal complex (DVC) can prevent social withdrawal. These brainstem nuclei contribute multiple neuronal projections that target different components of autonomic and stress-related neurocircuitry. In particular, catecholaminergic neurons in the ventrolateral medulla (VLM) and DVC target the hypothalamus and drive neuroendocrine responses to immune challenge, but their particular role in sickness behavior is not known. To test whether this catecholamine pathway also mediates sickness behavior, we compared effects of DVC inactivation with targeted lesion of the catecholamine pathway on exploratory behavior, which provides an index of motivation and fatigue, and associated patterns of brain activation assessed by immunohistochemical detection of c-Fos protein. LPS treatment dramatically reduced exploratory behavior, and produced a pattern of increased c-Fos expression in brain regions associated with stress and autonomic adjustments paraventricular hypothalamus (PVN), bed nucleus of the stria terminalis (BST), central amygdala (CEA), whereas activation was reduced in regions involved in exploratory behavior (hippocampus, dorsal striatum, ventral tuberomammillary nucleus, and ventral tegmental area). Both DVC inactivation and catecholamine lesion prevented reductions in exploratory behavior and completely blocked the inhibitory LPS effects on c-Fos expression in the behavior-associated regions. In contrast, LPS-induced activation in the CEA and BST was inhibited by DVC inactivation but not by catecholamine lesion. The findings support the idea that parallel pathways from immune-sensory caudal brainstem sources target distinct populations of forebrain neurons that likely mediate different aspects of sickness. The caudal medullary catecholaminergic projections to the hypothalamus may significantly contribute to brain mechanisms that induce behavioral "fatigue" in the context of physiological stressors.

Interferon-α reduces the density of monoaminergic axons in the rat brain

Interferon-alpha commonly induces depressive symptoms in clinical populations; however, the mechanism by which this occurs is unclear. Recent studies suggest that the degeneration of axons containing serotonin and noradrenaline is involved in the pathophysiology of depression. The present immunohistochemical study shows that the density of serotonergic axons decreased in the ventral medial prefrontal cortex and amygdala in the interferon-alpha-treated animals. Additionally, interferon-alpha induced decreases in the density of noradrenergic axons in the dorsal medial prefrontal cortex, ventral medial prefrontal cortex, and dentate gyrus. These results support the hypothesis that long-term administration of interferon-alpha causes the degeneration of monoaminergic axons in specific brain regions, which might be associated with depressive symptoms occurring in interferon-alpha-treated patients.

Specificity and generality of the involvement of catecholaminergic afferents in hypothalamic responses to immune insults

Catecholamine-containing projections from the medulla have been implicated in the mediation of activational responses of the paraventricular nucleus of the hypothalamus (PVH) provoked by moderate doses of interleukin-1 (IL-1). To test the generality of this mechanism, rats bearing unilateral transections of aminergic projections were challenged with intravenous IL-1 (2 microg/kg), bacterial lipopolysaccharide (LPS; 0.1, 2.0, or 100 microg/kg), or saline and perfused 3 hours later; their brains were then prepared for quantitative analysis of Fos induction and relative levels of corticotropin-releasing factor (CRF) mRNA. LPS provoked a robust and dose-related increase in Fos expression within the PVH on the intact side of the brain at all doses tested; the response to IL-1 approximated that to the lowest LPS dose. On the lesioned side, Fos induction was significantly reduced at all dosage levels but was eliminated only at the lowest dosage. The percentage reduction was greatest (75%) in IL-1-challenged rats and was progressively less in animals treated with increasing LPS doses (67, 59, and 46%, respectively). Specificity of aminergic involvement was tested by using intra-PVH administration of the axonally transported catecholamine immunotoxin, antiDBH-saporin. This treatment abolished IL-1-induced elevations of Fos-ir and CRF mRNA in the PVH but left intact comparable responses to restraint stress. These data support a specific involvement of ascending catecholaminergic projections in mediating PVH responses to IL-1 and LPS. Residual Fos induction seen in lesioned animals in response to higher doses of LPS provides a basis for probing additional circuits that may be recruited in a hierarchical manner in response to more strenuous or complex immune insults.

Immunolesions of glucoresponsive projections to the arcuate nucleus alter glucoprivic-induced alterations in food intake, luteinizing hormone secretion, and GALP mRNA, but not sex behavior in adult male rats

Metabolic signals such as insulin, leptin and glucose are known to alter hypothalamic function. Although insulin and leptin are known to directly alter hypothalamic areas that regulate reproduction, the mechanisms by which glucose alters reproductive function are not as clear. Catecholaminergic neurons in the A1/C1 region in the hindbrain are glucose-responsive and project to the arcuate nucleus. To determine if this pathway is involved in the regulation of sex behavior and luteinizing hormone (LH) secretion, this catecholaminergic pathway was lesioned with injections of saporin conjugated with anti-dopamine-beta-hydroxylase (DSAP) or unconjugated saporin (SAP) in adult male rats. Rats were given glucoprivic challenges and feeding and sex behavior was observed. As was expected, the DSAP-treated rats showed decreased feeding during glucoprivation (250 mg/kg 2-deoxy-D-glucose, 2DG) compared to SAP controls. Glucoprivation caused a significant reduction in sex behavior in both SAP and DSAP animals equally, compared to saline treatments (p < 0.05). At the end of the experiment, animals were given a final challenge with 2DG or saline, euthanized by decapitation and trunk blood was assayed for plasma LH levels. In situ hybridization analysis revealed that 2DG treatment caused a significant reduction in GALP mRNA in SAP controls compared to saline treatment. This reduction in GALP mRNA was prevented with DSAP treatment. In SAP animals, 2DG elicited a significant decrease in plasma LH levels (p < 0.05); this reduction in plasma LH was absent in the DSAP-treated male rats. These data indicate that the A1/C1 efferents to the ventromedial hypothalamus are involved in the glucostatic regulation of GALP mRNA, feeding behavior and LH secretion, but not sex behavior in the adult male rat.

Retrograde Axonal Transport of Dopamine Beta Hydroxylase Antibodies by Neurons in the Trigeminal Ganglion

In this study we describe a population of neurons in the adult rat trigeminal ganglion (TG) that express dopamine beta-hydroxylase (DBH) and tyrosine hydroxylase (TH), and transport anti-DBH from their terminals. We have used NGF and NT3 labeled with biotin and anti-p75NTR labeled with FITC to examine the transport of neurotrophins and their receptors by these cells. In both the superior cervical ganglion (SCG) and the TG all neurons that transported anti-DBH transported NGF. While 100% of the DBH positive neurons in the TG also transported NT3, approximately 25% of these neurons in the SCG failed to transport NT3. In the SCG virtually all the neurons transported anti-p75NTR with the neurotrophins while in the TG more than 25% of these neurons failed to transport anti-p75NTR with the neurotrophins. These findings suggest that DBH positive neurons in the TG depend upon target-derived NGF and NT3 for their noradrenergic phenotype.

A structural basis for CD8+ T cell-dependent recognition of non-homologous peptide ligands: implications for molecular mimicry in autoreactivity

Molecular mimicry of self-epitopes by viral antigens is one possible pathogenic mechanism underlying induction of autoimmunity. A self-epitope, mDBM, derived from mouse dopamine beta-mono-oxygenase (KALYDYAPI) sharing 44% sequence identity with the lymphocytic choriomeningitis virus-derived immunodominant epitope gp33 (KAVYNFATC/M), has previously been identified as a cross-reactive self-ligand, presentation of which results in autoimmunity. A rat peptide homologue, rDBM (KALYNYAPI, 56% identity to gp33), which displayed similar properties to mDBM, has also been identified. We herein report the crystal structure of H-2Db.rDBM and a comparison with the crystal structures of the cross-reactive H-2Db.gp33 and non-cross-reactive H-2Db.gp33 (V3L) escape variant (KALYNFATM, 88% identity to gp33). Despite the large sequence disparity, rDBM and gp33 peptides are presented in nearly identical manners by H-2Db, with a striking juxtaposition of the central sections of both peptides from residues p3 to p7. The structural similarity provides H-2Db in complex with either a virus-derived or a dopamine beta-mono-oxygenase-derived peptide with a shared antigenic identity that conserves the positioning of the heavy chain and peptide residues that interact with the T cell receptor (TCR). This stands in contrast to the structure of H-2Db.gp33 (V3L), in which a single conserved mutation, also present in rDBM, induces large movements of both the peptide backbone and the side chains that interact with the TCR. The TCR-interacting surfaces of the H-2Db.rDBM and H-2Db.gp33 major histocompatibility complexes are very similar with regard to shape, topology, and charge distribution, providing a structural basis for CD8 T cell activation by molecular mimicry and potential subsequent development of autoreactivity.

Increased lymphocyte dopamine beta-hydroxylase immunoreactivity in Alzheimer's disease: compensatory response to cholinergic deficit?

There is growing interest in the characterization of peripheral blood lymphocytes (PBL) as a biological tool with which to investigate changes in the neurotransmitter-receptor system in neurodegenerative disorders. Here we show a slight decrease in acetylcholinesterase (AChE) and a significant increase in dopamine beta-hydroxylase (DBH) immunoreactivity in the PBL of patients with probable Alzheimer's disease (AD). Therapy with AChE inhibitors completely reversed the increase in DBH immunoreactivity. We hypothesize that the increase in DBH immunoreactivity may represent a compensatory response to cholinergic impairment. Our findings suggest that neurochemical interactions between the noradrenergic and cholinergic systems may be measured at a peripheral level in AD.

Comparison of nerve terminal events in vivo effecting retrograde transport of vesicles containing neurotrophins or synaptic vesicle components

Although vesicular retrograde transport of neurotrophins in vivo is well established, relatively little is known about the mechanisms that underlie vesicle endocytosis and formation before transport. We demonstrate that in vivo not all retrograde transport vesicles are alike, nor are they all formed using identical mechanisms. As characterized by density, there are at least two populations of vesicles present in the synaptic terminal that are retrogradely transported along the axon: those containing neurotrophins (NTs) and those resulting from synaptic vesicle recycling. Vesicles containing nerve growth factor (NGF), NT-3, or NT-4 had similar densities with peak values at about 1.05 g/ml. Synaptic-derived vesicles, labeled with anti-dopamine beta-hydroxylase (DBH), had densities with peak values at about 1.16 g/ml. We assayed the effects of pharmacologic agents in vivo on retrograde transport from the anterior eye chamber to the superior cervical ganglion. Inhibitors of phosphatidylinositol-3-OH (PI-3) kinase and actin function blocked transport of both anti-DBH and NGF, demonstrating an essential role for these molecules in retrograde transport of both vesicle types. Dynamin, a key element in synaptic vesicle recycling, was axonally transported in retrograde and anterograde directions, and compounds able to interfere with dynamin function had a differential effect on retrograde transport of NTs and anti-DBH. Okadaic acid significantly decreased retrograde axonal transport of anti-DBH and increased NGF retrograde transport. We conclude that there are both different and common proteins involved in endocytosis and targeting of retrograde transport of these two populations of vesicles.

Immunotoxic destruction of distinct catecholaminergic neuron populations disrupts the reproductive response to glucoprivation in female rats

We tested the hypothesis that hindbrain catecholamine (norepinephrine or epinephrine) neurons, in addition to their essential role in glucoprivic feeding, are responsible for suppressing estrous cycles during chronic glucoprivation. Normally cycling female rats were given bilateral injections of the retrogradely transported ribosomal toxin, saporin, conjugated to monoclonal dopamine beta-hydroxylase antibody (DSAP) into the paraventricular nucleus (PVN) of the hypothalamus to selectively destroy norepinephrine and epinephrine neurons projecting to the PVN. Controls were injected with unconjugated saporin. After recovery, we assessed the lesion effects on estrous cyclicity under basal conditions and found that DSAP did not alter estrous cycle length. Subsequently, we examined effects of chronic 2-deoxy-d-glucose-induced glucoprivation on cycle length. After two normal 4- to 5-d cycles, rats were injected with 2-deoxy-d-glucose (200 mg/kg every 6 h for 72 h) beginning 24 h after detection of estrus. Chronic glucoprivation increased cycle length in seven of eight unconjugated saporin rats but in only one of eight DSAP rats. Immunohistochemical results confirmed loss of dopamine beta-hydroxylase immunoreactivity in PVN. Thus, hindbrain catecholamine neurons with projections to the PVN are required for inhibition of reproductive function during chronic glucose deficit but are not required for normal estrous cyclicity when metabolic fuels are in abundance.

Weak agonist self-peptides promote selection and tuning of virus-specific T cells

Recent progress has begun to define the interactions and signaling pathways that are triggered during positive selection. To identify and further examine self-peptides that can mediate positive selection, we searched a protein-database to find peptides that have minimal homology with the viral peptide (p33) that activates a defined P14 transgenic TCR. We identified four peptides that could bind the restriction element H-2D(b) and induce proliferation of P14 transgenic splenocytes at high concentration. Two of the four peptides (DBM and RPP) were able to positively select the virus-specific TCR in fetal thymic organ culture but were unable to induce clonal deletion. Reverse-phase HPLC and mass spectrometry demonstrated that these peptides were presented by H-2D(b) molecules on thymic epithelial cell lines. We also examined whether the selecting ligands altered T cell responsiveness in vitro. DBM-selected T cells lost their ability to respond to the positively selecting ligand DBM, whereas RPP-selected T cells only retained their ability to respond to high concentrations of RPP. These results demonstrate that self-peptides that mediate positive selection can differentially "tune" the activation threshold of T cells and alter the functional repertoire of T cells.

Immunolesion of norepinephrine and epinephrine afferents to medial hypothalamus alters basal and 2-deoxy-D-glucose-induced neuropeptide Y and agouti gene-related protein messenger ribonucleic acid expression in the arcuate nucleus

Neuropeptide Y (NPY) and agouti gene-related protein (AGRP) are orexigenic peptides of special importance for control of food intake. In situ hybridization studies have shown that NPY and AGRP mRNAs are increased in the arcuate nucleus of the hypothalamus (ARC) by glucoprivation. Other work has shown that glucoprivation stimulates food intake by activation of hindbrain glucoreceptor cells and requires the participation of rostrally projecting norepinephrine (NE) or epinephrine (E) neurons. Here we determine the role of hindbrain catecholamine afferents in glucoprivation-induced increase in ARC NPY and AGRP gene expression. The selective NE/E immunotoxin saporin-conjugated antidopamine-beta-hydroxylase (anti-dbetah) was microinjected into the medial hypothalamus and expression of AGRP and NPY mRNA was analyzed subsequently in the ARC under basal and glucoprivic conditions using (33)P-labeled in situ hybridization. Saporin-conjugated anti-dbetah virtually eliminated dbetah-immunoreactive terminals in the ARC without causing nonspecific damage. These lesions significantly increased basal but eliminated 2-deoxy-D-glucose-induced increases in AGRP and NPY mRNA expression. Results indicate that hindbrain catecholaminergic neurons contribute to basal NPY and AGRP gene expression and mediate the responsiveness of NPY and AGRP neurons to glucose deficit. Our results also suggest that catecholamine neurons couple potent orexigenic neural circuitry within the hypothalamus with hindbrain glucose sensors that monitor brain glucose supply.

Intrinsic choroidal neurons in the duck eye receive sympathetic input: anatomical evidence for adrenergic modulation of nitrergic functions in the choroid

Intrinsic choroidal neurons (ICN) in the duck eye form an intramural ganglionic plexus that may subserve complex integrative functions. A key feature of such ganglia is an innervation by sympathetic postganglionic neurons. The present study was thus aimed at determining the sympathetic postganglionic innervation of ICN. Choroids were processed for double immunofluorescence labelling with the following markers: tyrosine-hydroxylase (TH)/nitric oxide synthase (nNOS), TH/galanin (GAL), dopamine-beta-hydroxylase (DBH)/vasoactive intestinal polypeptide (VIP), TH/DBH and DBH/alpha-smooth-muscle actin (alphaSMA), and for triple immunofluorescence labelling with VIP/DBH/TH. Epifluorescence and confocal laser scanning microscopy were used for evaluation. Immunoperoxidase staining for TH or DBH in combination with NADPH-diaphorase histochemistry was applied for electron microscopy. ICN spread over the entire choroid but were concentrated in an equatorial zone passing obliquely from naso-cranial to temporocaudal. More than 80% of nNOS-positive ICN showed close appositions of TH/DBH-immunoreactive varicose nerve fibres at the light-microscopic level, as could be confirmed by confocal laser scanning microscopy. Ultrastructurally, these appositions could be defined as both synapses or close contacts without synaptic specialisation. Vascular and non-vascular smooth muscle fibres also received TH/DBH-immunopositive innervation. Our findings suggest that most ICN receive a sympathetic input that might modulate their nitrergic effects upon vascular and non-vascular smooth muscle fibres in the choroid and that they may have more complex functions than merely being a simple parasympathetic relay.

Initial characterization of the transplant of immortalized chromaffin cells for the attenuation of chronic neuropathic pain

Cultures of embryonic day 17 (E17) rat adrenal and neonatal bovine adrenal cells were conditionally immortalized with the temperature-sensitive allele of SV40 large T antigen (tsTag) and chromaffin cell lines established. Indicative of the adrenal chromaffin phenotype, these cells expressed immunoreactivity (ir) for tyrosine hydroxylase (TH), the first enzyme in the synthetic pathway for catecholamines. At permissive temperature in vitro (33 degrees C), these chromaffin cells are proliferative, have a typical rounded chromaffin-like morphology, and contain detectable TH-ir. At nonpermissive temperature in vitro (39 degrees C), these cells stop proliferating and express increased TH-ir. When these immortalized chromaffin cells were transplanted in the lumbar subarachnoid space of the spinal cord I week after a unilateral chronic constriction injury (CCI) of the rat sciatic nerve, they survived longer than 7 weeks on the pia mater around the spinal cord and continued to express TH-ir. Conversely, grafted chromaffin cells lost Tag-ir after transplant and Tag-ir was undetectible in the grafts after 7 weeks in the subarachnoid space. At no time did the grafts form tumors after transplant into the host animals. These grafted chromaffin cells also expressed immunoreactivities for the other catecholamine-synthesizing enzymes 7 weeks after grafting, including: dopamine-beta-hydroxylase (DbetaH) and phenylethanolamine-N-methyltransferase (PNMT). The grafted cells also expressed detectable immunoreactivities for the opioid met-enkephalin (ENK), the peptide galanin (GAL), and the neurotransmitters y-aminobutyric acid (GABA) and serotonin (5-HT). Furthermore, after transplantation, tactile and cold allodynia and tactile and thermal hyperalgesia induced by CCI were significantly reduced during a 2-8-week period, related to the chromaffin cell transplants. The maximal antinociceptive effect occurred 1-3 weeks after grafting. Control adrenal fibroblasts, similarly immortalized and similarly transplanted after CCI, did not express any of the chromaffin antigenic markers, and fibroblast grafts had no effect on the allodynia and hyperalgesia induced by CCI. These data suggest that embryonic and neonatal chromaffin cells can be conditionally immortalized and will continue to express the phenotype of primary chromaffin cells in vitro and in vivo; grafted cells will ameliorate neuropathic pain after nerve injury and can be used as a homogeneous source to examine the mechanisms by which chromaffin transplants reverse chronic pain. The use of such chromaffin cell lines that are able to deliver antinociceptive molecules in models of chronic pain after nerve and spinal cord injury (SCI) offers a novel approach to pain management.

A preferential pole for exocytosis in cultured chromaffin cells revealed by confocal microscopy

Histological studies suggest that adrenal medulla chromaffin cells in situ are polarised, but functional evidence is lacking. We present here the first demonstration for polarisation of exocytosis in isolated, spherical, bovine chromaffin cells. Cells were stimulated with 70 mM K(+) to cause a marked enhancement of catecholamine release, monitored amperometrically. FM1-43 and dopamine beta-hydroxylase antibodies provided fluorescence confocal pictures that were 2-3-fold more intense in the bottom of the cells, as compared to equatorial or apex planes. This suggests that the solid phase to which the cell attaches serves as a 'trophic' signal for the polarisation of its secretory apparatus.

Bulimia nervosa and autoimmunity

The autoantibodies that react with dopamine and serotonin are of interest in the study of bulimia nervosa. These neurotransmitters play an important role in appetite control, sexual and social behavior, and stress responses, all of which form a part of the clinical picture of bulimia nervosa. Are these autoantibodies involved in the serotoninergic hypofunctioning present in bulimia nervosa? Are they a part of an immunity regulation system essential for the cerebral system's homeostasis? To address these questions, 31 bulimic females (diagnosed according to DSM-III-R criteria) were compared with 10 control subjects (matched to the patients for sex, age, and demographic/psychosocial features). Measurement of the activity of natural autoantibodies reacting with dopamine, dopamine-beta-hydroxylase and serotonin was performed by an enzyme-linked immunosorbent assay (ELISA) for typical immunoglobulins (IgG, IgM, IgA). All of the autoantibodies of the IgG type were lower in the bulimic group than in the control group, a difference that was statistically significant for IgG anti-serotonin and IgG anti-dopamine. There was a trend for the amount of IgM anti-dopamine to be lower in patients than in controls. Dopamine and serotonin are specific components of brain cells. It can therefore be hypothesized that these antigens acting with autoantibodies could be the antigenic cerebral targets reacting with 'anti-brain' antibodies. The study of these specific autoantibodies provides information about the immunological characteristics that may be related to brain disturbances.

Ovarian hormones differentially influence immunoreactivity for dopamine beta- hydroxylase, choline acetyltransferase, and serotonin in the dorsolateral prefrontal cortex of adult rhesus monkeys

Recent studies have shown that ovariectomy reduces, and subsequent hormone replacement restores the density of axons immunoreactive for tyrosine hydroxylase in the dorsolateral prefrontal cortex of adult female rhesus monkeys. The present study indicates that three additional extrathalamic frontal lobe afferents are also sensitive to changes in the ovarian hormone environment. Specifically, the combination of hormone manipulation with qualitative and quantitative analysis of immunocytochemistry for dopamine beta-hydroxylase, choline acetyltransferase, and serotonin in the primate prefrontal cortex revealed quantitative responses in both cholinergic and monoaminergic axons to changing ovarian hormone levels. However, whereas ovariectomy produced a modest net decrease in the density of fibers immunoreactive for choline acetyltransferase, this same treatment markedly increased the density of axons immunoreactive for dopamine beta-hydroxylase and for serotonin. Further, the effects of ovariectomy on these afferent systems were differentially attenuated by estrogen verses estrogen plus progesterone hormone replacement. Estrogen was as effective as estrogen plus progesterone in stimulating normal prefrontal immunoreactivity for choline acetyltransferase and dopamine beta-hydroxylase. The dual replacement of estrogen plus progesterone, however, was a much more potent influence than estrogen alone for serotonin immunoreactivity. Thus, ovarian hormones appear to provide stimulation that differentially affects each of four chemically identified extrathalamic prefrontal afferent systems examined to date, and may have roles in maintaining the normal balance and functional interactions between these neurotransmitter systems.

Dopamine beta-hydroxylase deficiency impairs cellular immunity

Norepinephrine, released from sympathetic neurons, and epinephrine, released from the adrenal medulla, participate in a number of physiological processes including those that facilitate adaptation to stressful conditions. The thymus, spleen, and lymph nodes are richly innervated by the sympathetic nervous system, and catecholamines are thought to modulate the immune response. However, the importance of this modulatory role in vivo remains uncertain. We addressed this question genetically by using mice that lack dopamine beta-hydroxylase (dbh-/- mice). dbh-/- mice cannot produce norepinephrine or epinephrine, but produce dopamine instead. When housed in specific pathogen-free conditions, dbh-/- mice had normal numbers of blood leukocytes, and normal T and B cell development and in vitro function. However, when challenged in vivo by infection with the intracellular pathogens Listeria monocytogenes or Mycobacterium tuberculosis, dbh-/- mice were more susceptible to infection, exhibited extreme thymic involution, and had impaired T cell function, including Th1 cytokine production. When immunized with trinitrophenyl-keyhole limpet hemocyanin, dbh-/- mice produced less Th1 cytokine-dependent-IgG2a antitrinitrophenyl antibody. These results indicate that physiological catecholamine production is not required for normal development of the immune system, but plays an important role in the modulation of T cell-mediated immunity to infection and immunization.

Monoamine- and histamine-synthesizing enzymes and neurotransmitters within neurons of adult human cardiac ganglia

BACKGROUND

Cardiac ganglia were originally thought to contain only cholinergic neurons relaying parasympathetic information from preganglionic brain stem neurons to the heart. Accumulating evidence, however, suggests that cardiac ganglia contain a heterogeneous population of neurons that synthesize or respond to several different neurotransmitters and neuropeptides. Reports regarding monoamine and histamine synthesis and neurotransmission within cardiac ganglia, however, present conflicting information or are limited in number. Furthermore, very few studies have examined the neurochemistry of adult human cardiac ganglia. The purpose of this study was, therefore, to determine whether monoamine- and histamine-synthesizing enzymes and neurotransmitters exist within neurons of adult human cardiac ganglia.

METHODS AND RESULTS

Human heart tissue containing cardiac ganglia was obtained during autopsies of patients without cardiovascular pathology. Avidin-biotin complex immunohistochemistry was used to demonstrate tyrosine hydroxylase, L-dopa decarboxylase, dopamine beta-hydroxylase, phenylethanolamine-N-methyltransferase, tryptophan hydroxylase, and histidine decarboxylase immunoreactivity within neurons of cardiac ganglia. Dopamine, norepinephrine, serotonin, and histamine immunoreactivity was also found in ganglionic neurons. Omission or preadsorption of primary antibodies from the antisera and subsequent incubation with cardiac ganglia abolished specific staining in all cases examined.

CONCLUSIONS

Our results suggest that neurons within cardiac ganglia contain enzymes involved in the synthesis of monoamines and histamine and that they contain dopamine, norepinephrine, serotonin, and histamine immunoreactivity. Our findings suggest a putative role for monoamine and histamine neurotransmission within adult human cardiac ganglia. Additional, functional evidence will be necessary to evaluate what the physiological role of monoamines and histamine may be in neural control of the adult human heart.

Colocalization of ChAT, DbetaH and NADPH-d in the pancreatic neurons of the newborn guinea pig

Choline acetyltransferase (ChAT) as a rate-limiting enzyme in the biosynthetic pathway of acetylcholine is thought to be present in all cholinergic neurons. However, its immunoreactivity has not been successfully applied to the study of cholinergic neurons in the pancreas. In a previous study in the pancreas of newborn guinea pig we reported the colocalization of nicotinamide adenine dinucleotide hydrogen phosphate-diaphorase (NADPH-d), a marker for nitric oxide synthase (NOS) with various neuropeptides as well as dopamine-beta-hydroxylase (DbetaH), the enzyme responsible for converting dopamine to noradrenaline. Whether NADPH-d is colocalized with ChAT in the pancreatic neurons is not known. Also it would be interesting to find out whether noradrenaline and acetylcholine could be colocalized in the same pancreatic neurons. In the present study, a method for triple labelling of ChAT, DbetaH and NADPH-d was used to answer the above questions. Colocalization of ChAT, DbetaH and NADPH-d was constantly demonstrated in the same neurons in the same sections. It is concluded that some of the pancreatic neurons may utilize more than one neurotransmitter such as nitric oxide (NO), acetylcholine and noradrenaline to achieve their function. The possible cotransmission of acetylcholine and noradrenaline was extremely intriguing, and its mechanism and significance needs to be further investigated.

Morphological and immunocytochemical features of the pineal organ of C3H and C57BL mice at different stages of postnatal development

Considerable progress is currently being made in elucidating the molecular basis of the circadian (photoneuroendocrine) system by use of transgenic mice generated from the inbred strains C57BL and C3H. As in all other vertebrate species, the pineal organ is an important component of the photoneuroendocrine system in these mouse strains, but very little is known about its morphological and immunocytochemical features. We therefore investigated the pineal organ and the adjacent epithalamic region of adult, 10-, and 5-day-old C57BL and C3H mice for S-antigen, serotonin, and dopamine-ss-hydroxylase (DBH) immunoreactions. In adult animals, the pineal organ was more than 2 times bigger in C3H than in C57BL mice. In younger animals, this difference was already evident, but less pronounced. The S-antigen immunoreactivity was more intense in adult C3H than in C57BL mice. This difference developed with increasing age; it was not yet detectable in 5-day-old animals. The intensity of the serotonin immunoreaction was similar in both strains at all stages investigated. However, the serotonin immunoreaction was more pronounced in adult than in young animals. The relative DBH-immunoreactive area (used as a marker for the sympathetic innervation of the pineal organ) was much bigger in C3H than in C57BL mice; within each strain it remained relatively constant during postnatal development. Adult individuals of both strains contained S-antigen- and serotonin-immunoreactive cells in the habenular complex. Their number increased with age, but they were always more numerous in C3H. In conclusion, the study has shown considerable differences in pineal morphology between C3H and C57BL, which may be related to the well-known differen- ces in melatonin formation between these two strains.

Destruction of locus coeruleus neuronal perikarya after injection of anti-dopamine-B-hydroxylase immunotoxin into the olfactory bulb of the rat

Saporin, a ribosome-inactivating protein, was coupled to a monoclonal antibody to dopamine-B-hydroxylase (DBH) and injected unilaterally into the olfactory bulb of rats. After 4-13 days survival, the rat brain was processed histologically and the locus coerulei (LC) examined with Nissl and anti-DBH staining. There were degenerating dendrites in surviving LC neurons on the side ipsilateral to the immunotoxin-injected olfactory bulb. The number of Nissl-positive LC neurons in a transverse section through the caudal one third of the LC was reduced from 116+/-10 to 50+/-8 neurons (P < 0.01, n = 7) and the number of DBH-positive neurons in the more rostral LC sections was reduced from 13+/-2 to 5+/-1 (P < 0.05, n = 4). Our results indicate that it is possible to lesion LC neurons via retrograde intraaxonal transport of saporin-anti-DBH immunotoxin from the olfactory bulb.

Innervation of the lumbar facet joints. Origins and functions

STUDY DESIGN

The levels of dorsal root ganglia and paravertebral sympathetic ganglia innervating the lumbar facet joint were investigated in rats using the retrograde transport method. The pathways and functions of the nerve fibers supplying the lumbar facet joint were determined immunohistochemically.

OBJECTIVES

To study lumbar facet pain in relation to its innervation.

SUMMARY OF BACKGROUND DATA

The lumbar facet joints have been reported to be innervated segmentally. Little is known, however, about the origins and functions of the nerve fibers.

METHODS

Cholera toxin B subunit, a neural tracer, was placed in the L5-L6 facet joint, and the bilateral dorsal root ganglia and paravertebral sympathetic ganglia were examined immunohistochemically. The serial sections of lumbar vertebrae of newborn rats and the sections of the facet joint capsules, dorsal root ganglia, and paravertebral sympathetic ganglia of adult rats were investigated immunohistochemically. The pathways of the nerve fibers supplying the facet joint were reconstituted.

RESULTS

Labeled neurons existed in ipsilateral dorsal root ganglia from L1 to L5 and in paravertebral sympathetic ganglia from T12 to L6. The dorsal ramus of the spinal nerve and rami communicantes were connected to each other by calcitonin gene-related peptide immunoreactive fibers and dopamine beta-hydroxylase immunoreactive fibers.

CONCLUSIONS

The L5-L6 facet joint was innervated by ipsilateral dorsal root ganglia and paravertebral sympathetic ganglia, segmentally and nonsegmentally. Some of the sensory fibers from the facet joint may pass through the paravertebral sympathetic trunk, reaching L1 and/or L2 dorsal root ganglia. Inguinal and/or anterior thigh pain with lower lumbar facet joint lesions may be explained as referred pain.

Noradrenergic and peptidergic innervation of the testis and epididymis in the male pig

This study was designed to investigate the distribution of noradrenaline (NE)- and peptide-containing nerves in the testis of the boar. Testes, as well as caput and cauda epididymides from five 5 week-old and 3 adult boars were sectioned and immunostained with antisera to tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (D beta H), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP), Leu-enkephalin (L-ENK) and somatostatin (SOM). In addition, double-labelling immunofluorescence method was used to disclose the pattern of co-existence of these substances in the nerve fibres. The most abundant innervation was found in the cauda epididymidis, and the density of the nerves distinctly decreased towards the caput epididymidis. The testicular parenchyma and caput epididymidis was supplied with very scattered TH-, D beta H-, NPY-, VIP-, SP-, CGRP-, L-ENK- and SOM-containing nerve fibres. The present study has demonstrated for the first time the existence of CGRP, L-ENK and SOM in nerve fibres innervating the testis of a vertebrate species. Different subpopulations of nerve fibres, including TH+/D beta H+, D beta H+/NPY+, D beta H-/NPY+, D beta H+/NPY-, D beta H+/VIP+, D beta H-/VIP+, D beta H+/SP+, D beta H-/SP+, D beta H+/L-ENK+ D beta H-/L-ENK+, D beta H+/SOM+ and D beta H-/SOM+, were localized and documented.

Modulation of forebrain electroencephalographic activity in halothane-anesthetized rat via actions of noradrenergic beta-receptors within the medial septal region

The locus coeruleus (LC)-noradrenergic system modulates forebrain electroencephalographic (EEG) activity in halothane-anesthetized rat. For example, unilateral enhancement of LC neuronal activity increases cortical EEG (ECoG) and hippocampal EEG (HEEG) indices of arousal bilaterally (Berridge and Foote, 1991). Conversely, bilateral suppression of LC discharge activity increases EEG measures of sedation (Berridge, et al., 1993b). The EEG-activating effects of LC stimulation appear to involve noradrenergic beta-receptors (Berridge and Foote, 1991). Two candidate sites at which LC efferents could influence ECoG and HEEG are the medial septum/vertical limb of the diagonal band of Broca (MS) and the substantia innominata/nucleus basalis of Meynert (SI). To determine whether norepinephrine mediates such actions within either of these regions, the EEG effects of small infusions of a beta-agonist or antagonist into MS or SI were examined in halothane-anesthetized rat. Unilateral infusions (150 nl) of the beta-agonist isoproterenol (ISO) (3.75 microg, 17 nmol) into MS, but not SI (150-450 nl), elicited robust bilateral activation of ECoG and HEEG. Infusions of glutamate (0.5 microg, 3.0 nmol) into either MS or SI elicited bilateral ECoG and HEEG activation. Neither vehicle infusions into MS nor infusions of ISO into regions adjacent to MS altered forebrain EEG activity. Bilateral, but not unilateral, MS infusions of the beta-antagonist timolol (3.75 microg, 8.7 nmol) decreased EEG indices of arousal in the lightly anesthetized preparation. Power spectral analyses provided quantitative confirmation of these qualitative observations. These results indicate that under these experimental conditions, noradrenergic efferents, presumably arising from LC, modulate forebrain EEG state via actions at beta-receptors located within MS. The results presented in the accompanying report extend these observations to the unanesthetized preparation and incorporate additional measures of behavioral state.

Targeting toxins to neural antigens and receptors

Immunotoxins have been used to study the targeting of biologically active substances at neurons in vivo and to make experimental neural lesions. OX7-saporin, directed against Thy 1, destroys any neuron. 192 IgG-saporin, directed against the 'low affinity' neurotrophin receptor (p 75NTR), selectively destroys neurons expressing this receptor (sympathetic, sensory, cholinergic basal forebrain, cerebellar Purkinje). Anti-D beta H-saporin, directed against dopamine beta-hydroxylase, the enzyme that converts dopamine to norepinephrine, selectively destroys noradrenergic neurons (sympathetic, CNS). These agents show that several types of neural antigens may prove useful in treating pain, and anti-D beta H-saporin may be active against pheochromocytoma or neuroblastoma.

Dopamine-beta-hydroxylase and tyrosine hydroxylase immunoreactive neurons in the human brainstem

Immunohistochemistry of dopamine-beta-hydroxylase in the human hind brain indicates that neuronal cell bodies containing the antigen form prominent populations in the nucleus tractus solitarius and nearby medial and dorsal edge of the medial vestibular nucleus. They are frequent in and around the periphery of the dorsal motor nucleus of the vagus and in an oblique band extending from that region to the ventrolateral aspect of the reticular formation, where they are most numerous at the mid medullary levels. Dopamine-beta-hydroxylase immunoreactive neurons are also closely packed in the nuclei coeruleus and subcoeruleus. Concomitant immunohistochemistry for tyrosine hydroxylase demonstrates small numbers of neuronal cell bodies that are reactive only for this antigen, and which do not contain detectable dopamine-beta-hydroxylase. Such neurons are present in the nucleus tractus solitarius, the pontine lateral parabrachial nucleus and within the core of the rostral pontine reticular formation. Some medullary and pontine axon bundles similarly stain for tyrosine hydroxylase but not for dopamine-beta-hydroxylase. These differential staining patterns suggest, among other possibilities, that in humans some neurons of the caudal brainstem are dopamine (if they contain the second step catecholamine synthesizing enzyme, aromatic L-aminoacid decarboxylase) rather than noradrenaline or adrenaline containing catecholamine neurotransmitters.

Anti-dopamine beta-hydroxylase immunotoxin-induced sympathectomy in adult rats

Anti-dopamine beta-hydroxylase immunotoxin (DHIT) is an antibody-targeted noradrenergic lesioning tool comprised of a monoclonal antibody against the noradrenergic enzyme, dopamine beta-hydroxylase, conjugated to saporin, a ribosome-inactivating protein. Noradrenergic-neuron specificity and completeness and functionality of sympathectomy were assessed. Adult, male Sprague-Dawley rats were given 28.5, 85.7, 142 or 285 micrograms/kg DHIT i.v. Three days after injection, a 6% to 73% decrease in the neurons was found in the superior cervical ganglia of the animals. No loss of sensory, nodose and dorsal root ganglia, neurons was observed at the highest dose of DHIT. In contrast, the immunotoxin, 192-saporin (142 micrograms/kg), lesioned all three ganglia. To assess the sympathectomy, 2 wk after treatment (285 micrograms/kg), rats were anesthetized with urethane (1 g/kg) and cannulated in the femoral artery and vein. DHIT-treated animals' basal systolic blood pressure and heart rate were significantly lower than controls. Basal plasma norepinephrine levels were 41% lower in DHIT-treated animals than controls. Tyramine-stimulated release of norepinephrine in DHIT-treated rats was 27% of controls. Plasma epinephrine levels of DHIT animals were not reduced. DHIT-treated animals exhibited a 2-fold hypersensitivity to the alpha-adrenergic agonist phenylephrine. We conclude that DHIT selectively delivered saporin to noradrenergic neurons resulting in destruction of these neurons. Anti-dopamine beta-hydroxylase immunotoxin administration produces a rapid, irreversible sympathectomy.

Noradrenergic lesioning with an anti-dopamine beta-hydroxylase immunotoxin

Sympathectomy has been achieved by a variety of methods but each has its limitations. These include lack of tissue specificity, incomplete lesioning, and the age range of susceptibility to the lesioning. To circumvent these drawbacks, an immunotoxin was constructed using a monoclonal antibody against the noradrenergic specific enzyme dopamine beta-hydroxylase (D beta H) coupled via a disulfide bond to saporin, a ribosomal inactivating protein. Three days after intravenous injection of the anti-D beta H immunotoxin (50 micrograms) into adult Sprague-Dawley rats, 66% of neurons in the superior cervical ganglia were chromatolytic. Superior cervical ganglia neurons were poisoned in 1 day old and 1 week old (86% of neurons) neonatal rats following subcutaneous injection of 3.75 and 15 micrograms, respectively. The anti-D beta H immunotoxin will be a useful tool in the study of the peripheral noradrenergic system in adult and neonatal animals.

Ultrastructural organization of the noradrenergic innervation of the superficial gray layer of the hamster's superior colliculus

Immunocytochemistry with an antibody-directed tyrosine hydroxylase (TH) was combined with electron microscopy and serial-section analysis to examine the synaptic organization of the catecholaminergic projection to the stratum griseum superficiale (SGS) of the hamster's superior colliculus (SC). A total of 250 TH-immunoreactive profiles within SGS were examined. Of these, 114 (45.6%) made synaptic contacts; 81 (71.1%) were axodendritic, and the remainder (33, 28.9%) were axo-axonic. Serial-section analysis was employed to evaluate the presence or absence of synaptic contacts for 26 profiles. Overall, 19 (73.1%) of the profiles followed through serial sections exhibited synaptic contacts. Double staining of single sections with antibodies directed against TH and dopamine-beta-hydroxylase (D beta H) and examination in the light microscope indicated that virtually all TH-positive fibers also contained D beta H. This indicated that the fibers examined at the electron microscopic level were noradrenergic rather than dopaminergic. These results suggest that norepinephrine may have both pre- and postsynaptic actions in the hamster's SC and that at least some of these effects are mediated by conventional synapses.

Sensory and autonomic innervation of the rat eyelid: neuronal origins and peptide phenotypes

Neuronal origins, peptide phenotypes and target distributions were determined for sensory and autonomic nerves projecting to the eyelid. The retrograde tracer, Fluoro-Ruby, was injected into the superior tarsal muscle and meibomian gland of Sprague-Dawley rats. Labelled neurons were observed within the pterygopalatine (31 +/- 6 of a total of 8238 +/- 1610 ganglion neurons), trigeminal (173 +/- 43 of 62,082 +/- 5869) and superior cervical ganglia (184 +/- 35 of 21,900 +/- 1741). Immunostaining revealed vasoactive intestinal polypeptide immunoreactivity (VIP-ir) in nearly all Fluoro-Ruby-labelled pterygopalatine ganglion neurons (86 +/- 5%) but only rarely in trigeminal (0.3 +/- 0.3%) or superior cervical (1.4 +/- 1.4%) ganglion neurons. Calcitonin gene-related peptide (CGRP)-ir was not observed in pterygopalatine or superior cervical ganglion somata, but was present in 24 +/- 4% of trigeminal neurons. Bright dopamine beta-hydroxylase (DBH) immunofluorescence was observed in the majority of eyelid-projecting neurons within the superior cervical ganglia (65 +/- 5%) and lighter staining was detected in pterygopalatine neurons (63 +/- 3%), but no DBH-ir was observed in trigeminal neurons. Examination of eyelid sections revealed dense VIP-ir innervation of meibomian gland acini and vasculature and modest distribution within tarsal muscle. CGRP-ir fibers surrounded ductal and vascular elements of the meibomian gland and the perimeter of tarsal muscle. DBH-ir fibers were associated with meibomian gland blood vessels and acini, and were more densely distributed within tarsal muscle. This study provides evidence for prominent meibomian gland innervation by parasympathetic pterygopalatine ganglion VIP-ir neurons, with more restricted innervation by sensory trigeminal CGRP-ir and sympathetic neurons. Tarsal muscle receives abundant sympathetic innervation, as well as moderate parasympathetic and sensory CGRP-ir projections. The eyelid contains substantial non-CGRP-ir sensory innervation, the targets of which remain undetermined. The distribution of identified autonomic and sensory fibers is consistent with the idea that meibomian gland function, as well as that of the tarsal muscle, is regulated by peripheral innervation.

Relationships between spinocervical tract neurons and descending catecholamine-containing axons in the cat

Lumbosacral (L6-S1) spinal cord neurons in the cat were retrogradely labelled after uptake of horseradish peroxidase by their severed axons in the upper cervical (C3-C4) dorsolateral funiculus. Sections of L6-S1 containing labelled neurons were then processed immunocytochemically using antibodies against dopamine-beta-hydroxylase or tyrosine hydroxylase, two enzymes responsible for the synthesis of catecholamines. Two hundred and ninety eight retrogradely-labelled cells within laminae III-V of the dorsal horn were examined under high power (x 1000) with the light microscope. In Triton X-100-treated material, only 13% of these cells had catecholamine-containing varicosities closely apposed to their somata and proximal dendrites, which suggests that in comparison with the postsynaptic dorsal column pathway, spinocervical tract neurons are only sparsely innervated by descending catecholaminergic axons.

Distribution of dopaminergic fibers in the central division of the extended amygdala of the rat

The distribution of dopaminergic fibers in the principal components of the central extended amygdala (central amygdaloid nucleus (Ce), substantia innominata, and bed nucleus of the stria terminalis (BNST)), was studied using immunocytochemistry against tyrosine hydroxylase, dopamine beta-hydroxylase and dopamine. Dopamine fibers were found most densely distributed in the dorsolateral subdivision of the BNST and the lateral part of the Ce. Smaller numbers of dopaminergic fibers were found in the rest of the central extended amygdala. In contrast, dopamine beta-hydroxylase fibers were virtually absent from the dorsolateral bed nucleus of the stria terminalis and lateral part of the central amygdaloid nucleus, but were distributed in a moderate density in the medial part of Ce, dorsal substantia innominata and posterolateral BNST. Our results show that dopamine fibers are most concentration over those regions of the central extended amygdala with large numbers of GABAergic neurons whose projections remain within the central extended amygdala, while noradrenergic fibers are most heavily concentrated over those regions containing a large proportion of brainstem projection neurons. That dopamine fibers are concentrated over regions with GABAergic medium spiny neurons suggests that those regions might be organized as a striatal parallel.

Serotonin (5-HT) fibers of the rat dura mater: 5-HT-positive, but not authentic serotoninergic, tryptophan hydroxylase-like fibers

Serotonin (5-HT)-positive, but not tryptophan-5-hydroxylase (TPOH)-positive, authentic serotoninergic fibers were shown in the rat dura mater. 5-HT immunoreactive fibers in the dura are postulated to result from 5-HT uptake from circulating blood elements (e.g. platelets, mast cells) by perivascular sympathetic nerve fibers. A robust TPOH-immunoreactive mast cell population was identified in the dura; this result confirms the TPOH antibody specificity to cells known to synthesize 5-HT. While these results indicate that there are no authentic serotoninergic fibers in the dura mater, the mast cells, platelets and cerebrospinal fluid can serve as a source of 5-HT activating 5-HT receptors known to be present in this tissue.

Transitory noradrenergic and peptidergic nerves in the cat kidney

Indirect immunohistochemical methods were used to visualize nerves immunoreactive for tyrosine hydroxylase (TH), dopamine beta hydroxylase (DBH), neuropeptide Y, (NPY) and calcitonin gene-related peptide (CGRP) in sections of the kidneys of cats of different ages. Nerve terminals immunoreactive for TH, DBH and NPY innervated interlobar veins and the renal arterial tree including medullary vascular bundles of cats of each age studied. Most nerve terminals immunoreactive for CGRP innervated interlobar arteries. In kidneys of cats 2 to 10 weeks old, TH- and DBH-immunoreactive axons formed elaborate plexuses that were distributed throughout much of the outer two thirds of the inner medulla. Inner medullary NPY-immunoreactive nerve terminals formed sparse plexuses by comparison, thus suggesting a large population of TH-immunoreactive nerve terminals not immunoreactive for NPY. Plexuses immunoreactive for CGRP also innervated the inner medullae of young cats. Some inner medullary axons appeared degenerate in 8 and 10 week old cats, and no inner medullary nerve terminal plexuses were visualized in 12 week old or adult cats. Cell death or paring of axons resulting from mechanisms intrinsic to the neuronal population or from a change in trophic factors secreted or expressed by cells in the medulla may effect the loss of inner medullary nerve terminals in the kidneys of young cats.

Immunocytochemical evidence of well-developed dopaminergic and noradrenergic innervations in the frontal cerebral cortex of human fetuses at midgestation

The catecholaminergic (CA) innervation of the frontal lobe was visualized in 20- to 24-week-old human fetuses with immunocytochemical techniques, by use of antibodies raised against three synthetic enzymes of the CA pathway, tyrosine-hydroxylase (TH), dopamine-beta-hydroxylase (DBH), and phenylethanolamine-N-methyltransferase (PNMT). DBH-like immunoreactivity (IR) was probably labeling the noradrenergic (NA) fibers and terminals in the cerebral cortex since no PNMT-IR fibers were detected. In double-labeling TH-DBH experiments, 92-95% of the DBH-IR afferents were not labeled with TH antibodies, indicating that TH-like immunoreactivity (TH-IR) was found primarily in dopaminergic (DA) fibers. Although cortical layering had not yet occurred at this stage, the widespread CA innervation observed in the different areas and layers of the fetal frontal cortex was comparable to that previously described in the adult (Gaspar, Berger, Febvret, Vigny, and Henry: J. Comp. Neurol. 279:249-271, '89). At midgestation, the distribution of CA innervation was region and laminar specific: 1) The densest dopaminergic innervation in the cerebral cortex was located caudal to the genu of the corpus callosum: TH-IR fibers were abundant throughout all layers, from the medial telencephalon (future cingulate) to the dorsal areas (presumed motor cortices) and the lateral insular areas; 2) TH-IR fibers were less dense in the rostral prefrontal cortical anlage; 3) DBH-IR noradrenergic afferents were less numerous than the dopaminergic ones in all the cortical areas studied; 4) in all areas, the highest amount of TH and DBH-IR terminals was found in the upper subplate and in the lower part of the cortical plate, followed by the molecular layer and the intermediate zone. The deep subplate exhibited a lower number of positive fibers but contained TH-IR cell bodies. The presence of dense CA innervation in the immature cortical anlage of the human frontal lobe does not exclude a reorganization of DA and NA innervations within the different cortical layers and areas during the protracted pre- and postnatal period of development.

Recycling of a secretory granule membrane protein after stimulated secretion

Recycling of a secretory granule membrane protein, dopamine-beta-hydroxylase, was examined in primary cultures of bovine adrenal chromaffin cells. Cells were stimulated to secrete in the presence of antibodies directed against the luminal domain of dopamine-beta-hydroxylase. The location of the antibodies after various times of reincubation and after a second secretory stimulus was assessed using immunofluorescence microscopy. Stimulation led to the exposure of dopamine-beta-hydroxylase at the plasma membrane, which could be detected by a polyclonal antibody in living and fixed cells. The plasma membrane dopamine-beta-hydroxylase, either alone or complexed with antibody, was rapidly internalized after removal of the secretagogue. Internalized protein-antibody complex remained stable for at least 24 hours of reculture. Twenty four hours after stimulation the cells with internalized antibody could respond to further stimulation and some of the antibody was re-exposed at the plasma membrane. These findings were confirmed using FACS analysis. This suggests that the antibody-protein complex had returned to secretory granules that could respond to further secretagogue stimulation.

Serotonergic sprouting in primate MTP-induced hemiparkinsonism

Immunocytochemistry to serotonin, dopamine beta hydroxylase (DBH), and tyrosine hydroxylase (TH) was studied in the brains of 2 cebus monkeys that had developed permanent hemiparkinsonism after intracarotid injection of 1.2 mg N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and were sacrificed after 10-12 months. A pronounced depletion of TH-immunoreactive neurons was found in the substantia nigra, caudate nucleus, and putamen, ipsilaterally to the injected side. In these dopamine-denervated structures, the number of serotonergic fibers was increased in the ipsilateral compared with the contralateral side, or with an untreated control monkey. Serotonergic neurons in the brainstem appeared to be unaffected. Topography and number of DBH-positive fibers in the control and the MPTP-injected sides were comparable.

The noradrenergic innervation density of the monkey paraventricular nucleus is not altered by early social deprivation

A series of neuroanatomic analyses have been undertaken to identify potential neuropathological changes seen in monkeys exposed to early social deprivation, which leads to psychopathology, inappropriate responses to stress and appetitive disorders. The animals used in this study were either socially reared or maternal- and peer-deprived. Within this framework, the distribution and density of noradrenergic (and adrenergic) varicosities was assessed in the hypothalamic paraventricular nucleus of rhesus monkeys using dopamine-beta-hydroxylase immunohistochemistry combined with laser scanning microscopy. Quantitative analysis of dopamine-beta-hydroxylase-immunoreactive varicosity density within magnocellular and parvicellular regions revealed no significant differences between rearing conditions, suggesting that this chemically identified afferent input to the paraventricular nucleus was not affected by the early environmental insult of social deprivation. The apparent lack of vulnerability of the paraventricular nucleus to differential rearing conditions contrasts with the neuropathological changes observed in several discrete brain regions.

Effects of antibodies against acetylcholinesterase on the expression of peptides and catecholamine synthesizing enzymes in the rat adrenal gland

In the rat, systemic administration of murine monoclonal antibodies against acetylcholinesterase caused rapid piloerection and ptosis (within 30-60 min after the injection). Using indirect immunohistochemistry the effect of these antibodies on peptides and enzyme expression was studied in the rat adrenal gland. Four days after antibody administration a total disappearance of acetylcholinesterase-immunoreactive fibers was observed. However, groups of acetylcholinesterase-immunoreactive chromaffin cells and intramedullary ganglion cells, both cell types showing acetylcholinesterase immunoreactivity also in the control adrenal medulla, expressed increased immunoreactivity. Analysis revealed that the acetylcholinesterase-immunoreactive chromaffin cell groups lacked phenylethanolamine-N-methyltransferase staining both in controls and treated rats. Antibody administration also affected levels of several peptides present in nerve fibers and chromaffin cells. Thus, the number of cells expressing enkephalin, calcitonin gene-related peptide and galanin was dramatically increased compared to the very few cells observed containing these three peptides in the normal gland. The majority of cells expressing enkephalin after antibody treatment also showed phenylethanolamine-N-methyltransferase immunoreactivity. In contrast, the few chromaffin cells expressing strong enkephalin-like immunoreactivity in controls were phenylethanolamine-N-methyltransferase negative. The sparse networks of calcitonin gene-related peptide- and galanin-positive fibers found in control adrenals were unchanged after the antibody treatment. However, the dense network of enkephalin varicose fibers totally disappeared after the antibody injection. A few substance P- and somatostatin-immunoreactive cells, not present in the normal gland, appeared after administration of the antibodies, whereas no changes were encountered with regard to immunoreactive nerve fibers. No clear differences between normal and treated animals could be observed in chromaffin cells with regard to immunoreactivity for neuropeptide Y or any of the four catecholamine-synthesizing enzymes, tyrosine hydroxylase, aromatic 1-amino acid decarboxylase, dopamine beta-hydroxylase or phenylethanolamine-N-methyltransferase. The present findings demonstrating a disappearance of acetylcholinesterase- and enkephalin-immunoreactive nerve fibers in the adrenal gland after intravenous injection of acetylcholinesterase antibodies support earlier reports showing that these antibodies cause degeneration of preganglionic fibers, and that neuronal decentralization of the adrenal gland induces marked increases in the levels of several peptides in chromaffin cells.

Importance of hypothalamic function to stressor-induced responsiveness of the GABAA receptor in the cerebral cortex: a non-corticosterone influence

Catecholamine terminals in the paraventricular nucleus (PVN) of the hypothalamus of 60-day-old rats were destroyed by the stereotaxic injection of 6-hydroxydopamine into the PVN (6-OHDA; 9 micrograms/1.5 microliters bilaterally), and the rats were tested 2 weeks later. Lesions led to a 70% reduction of norepinephrine in the hypothalamus and a loss of dopamine-beta-hydroxylase immunoreactivity in the PVN. Furthermore, 6-OHDA lesions in the hypothalamus disrupted stressor-induced (15 min of restraint) changes in GABAA receptor function in the cerebral cortex (assessed by measuring chloride-facilitated benzodiazepine binding) but did not alter stressor-induced increases in plasma corticosterone levels. Additionally, the lesion did not change the responsiveness of the GABAA receptor to the corticosterone metabolite, allotetrahydrodeoxycorticosterone. These results indicate that stressor-induced changes in cortical GABAA receptor function are not driven by the stressor-induced release of corticosterone. A separate group of animals were tested for behavioral responses to challenge, and while 6-OHDA-induced lesions did not alter total scores in the test of environment-specific social interaction, the lesions did induce a change in composition of the behavior. Lesioned animals demonstrated increased physical (vigorous contact) interactions, similar to behavior previously observed in younger rats. The results of the behavioral study support a role for the GABAA receptor in the cerebral cortex in mediating appropriate behavioral responses to challenge in the adult rat. Thus, a hypothalamic lesion that prevented challenge-induced changes in GABAA receptor function in the cortex (with no change in the corticosterone response to the stressor) also led to altered behavioral responses to challenge.

Distribution of dopamine-containing neurons and fibres in the feline medulla oblongata: a comparative study using catecholamine-synthesizing enzyme and dopamine immunohistochemistry

The distribution of dopamine-immunoreactive neurons and fibres in the feline medulla oblongata was examined by immunocytochemistry with antisera to the catecholamine-synthesizing enzymes tyrosine hydroxylase, dopamine-beta-hydroxylase and phenylethanolamine-N-methyltransferase, and with antisera to the catecholamines dopamine and L-dihydroxyphenylalanine. Neurons immunoreactive for the catecholamine-synthesizing enzymes were found in two regions of the medulla, the ventrolateral A1 region and the dorsomedial A2 region. Double-staining studies with antisera to the enzymes indicated that a population of neurons within both regions were immunoreactive for tyrosine hydroxylase but not dopamine-beta-hydroxylase or phenylethanolamine-N-methyltransferase, implying that they synthesize dopamine. Studies using the dopamine antisera demonstrated the presence of dopamine-immunoreactive neurons in both the ventrolateral and dorsomedial regions of the medulla; in the dorsomedial region, they were found in the area postrema, nucleus tractus solitarius and dorsal motor vagal nucleus, mainly at levels caudal to the obex. Dopamine-immunoreactive fibres were found in several areas of the medulla including the nucleus tractus solitarius, inferior olive, dorsal motor vagal, spinal trigeminal, hypoglossal, cuneate, gracile, and raphe nuclei. Double-staining studies with antisera to dopamine and dopamine-beta-hydroxylase revealed a population of cells immunoreactive for dopamine alone. The presence of some double-stained neurons, however, implies some cross-reactivity of the dopamine antiserum with noradrenaline or adrenaline and/or recognition of dopamine present as a metabolic intermediary in some noradrenergic neurons. No L-dihydroxyphenylalanine-immunoreactive neurons were found in the medulla, although fibres were seen. These data provide evidence for the existence of catecholamine neurons which utilize dopamine as a final synthetic product within the medulla oblongata.

Morphological relationships between tyrosine hydroxylase-immunoreactive neurons and dopamine-beta-hydroxylase-immunoreactive fibres in dopamine cell group A15 of the sheep

Double immunocytochemical labelling with antibodies raised against tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase was used on semi-thin sections of sheep hypothalamus to investigate possible morphological relationships between dopamine neurons of group A15 and noradrenaline afferents to this area. Dopamine-beta-hydroxylase-immunoreactive (IR) fibres were found in the close proximity of dendrites of TH-IR neurons. At electron microscopic level, single immunocytochemical staining with TH antibodies revealed the presence of synaptic contacts between labelled or unlabelled axon terminals and anti-TH labelled dendrites. These observations suggest that in the sheep, TH-IR neurons of group A15 are controlled by non-catecholaminergic and catecholaminergic afferents. Catecholamine inputs could contain either dopamine or noradrenaline. The hypothesis of noradrenaline inputs to A15 is strongly supported by the results obtained after double labelling on semi-thin sections. Tyrosine hydroxylase-immunoreactive perikarya and dendrites often seemed to be partly surrounded by glial processes. This latter observation suggests that the synaptic investment of these neurons might be controlled by glial cells.

Projections from the commissural subnucleus of the solitary tract onto catecholamine cell groups of the ventrolateral medulla

Efferent projections of the commissural subnucleus of the solitary tract (COM) to the ventrolateral medulla were studied in the cat using anterograde labeling with biocytin combined with dopamine beta-hydroxylase immunohistochemistry. COM neurons were observed to send their axons densely to the areas of distribution of respiration-related neurons in the ventrolateral medulla, e.g. ventral respiratory group, Bötzinger complex. Axon terminals from COM neurons were further found in the areas of distribution of catecholamine neurons (C1 and A1 cell groups), that were distributed in the close vicinity of the reported respiration-related areas in the ventrolateral medulla. Putative synaptic contacts of axon terminals from COM neurons with catecholamine neurons were often observed in the C1 area.

Immunolocalization of catecholamine enzymes, serotonin, dopamine and L-dopa in the brain of Dicentrarchus labrax (Teleostei)

Antisera to serotonin (5-HT), dopamine, and L-dopa, and to the catecholamine synthesizing enzymes, tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), and phenylethanolamine N-methyl transferase (PNMT), were used to localize monoamine containing neurones in the brain of Dicentrarchus labrax (sea bass). In the brain stem, 5-HT-immunoreactive (ir) neurones were recognized in the ventrolateral medulla, vagal motor area, medullary, and mesencephalic raphe nuclei and in the dorsolateral isthmal tegmentum. In the hypothalamus, liquor-contacting 5-HT neurones were seen in various regions of the paraventricular organ. Virtually all regions of the brain contained a dense innervation by 5-HT fibres and terminals. DBH-ir neurones were restricted to three brain stem areas: the locus coeruleus, the area postrema, and the reticular formation of the lower medulla. Neurones in these three groups also displayed TH-ir, and in the latter area, PNMT-ir in addition. In the locus coeruleus and area postrema, TH-ir neurones outnumbered DBH-ir neurones, an observation substantiated by the presence of dopamine-ir neurones. In the forebrain, dopamine- and TH-ir neurones were found in the olfactory bulb, ventral/central telencephalon, periventricular preoptic, and suprachiasmatic areas, dorsolateral and ventromedial thalamus, and posterior tuberal nucleus. In the paraventricular organ, the distribution and morphology of dopamine-ir neurones was similar to that observed with anti-5-HT, but the vast majority of cells were not TH-ir, suggesting accumulation of dopamine by uptake from the ventricle, rather than by synthesis. L-dopa-ir neurones were found only in the central telencephalon, preoptic recess, and dorsolateral thalamus. Fibres and terminals immunoreactive for dopamine, TH, and DBH showed a broadly similar distribution. The results are discussed in relation to the monoaminergic systems previously reported in other teleostean species and the mammalian brain.

Selective effects on CRF neurons and catecholamine terminals in two stress-responsive regions of adult rat brain after prenatal exposure to diazepam

Earlier work demonstrated that prenatal exposure to diazepam (DZ) selectively affected the noradrenergic (NE) terminals in the hypothalamus, leading to decreased basal NE levels, turnover rate, and release in adult offspring as well as altered responses to stressors in these NE projections. The exposure also affected plasma hormonal responses to stressors. In the present work, we used immunocytochemistry to study the effects of prenatal DZ exposure on NE terminals and on corticotropin-releasing factor (CRF)-containing neurons in the paraventricular nucleus (PVN) of the hypothalamus. DZ exposure (2.5 or 10 mg/kg over gestational days 14-20) led to a decrease in dopamine-beta-hydroxylase (DBH)-immunoreactivity (-ir) and a decrease in CRF-ir containing cells within the PVN of adult rats. The exposure also decreased DBH-ir in the ventral portion of the bed nucleus of the stria terminalis (BNST) but did not affect CRF-ir in the oval nucleus of BNST. Therefore, this study provides anatomic evidence that targeting benzodiazepine binding sites prenatally affects two neurotransmitter systems involved in responses to stressors.