Universal Lead Screening Requirement: A California Case Study

OBJECTIVES

To estimate potential impacts of California Assembly Bill (AB) 1316: a requirement for universal screening and insurance coverage for child blood lead testing.

METHODS

In April 2017 the California Health Benefits Review Program (Oakland, CA) analyzed AB 1316 for the California legislature, including a systematic review of lead screening effectiveness, commercial insurer surveys regarding screening coverage, and actuarial utilization and cost implication assessments.

RESULTS

Universal screening requirements would increase child lead testing by 273%, raise affected populations' premiums by 0.0043%, and detect an additional 4777 exposed children 1 year after implementation.

CONCLUSIONS

The evidence for a net societal benefit of universal screening approach is limited and is not supported by prominent medical professional groups. Public Health Implications. California expanded targeted screening to identify additional children at higher risk for lead poisoning on the basis of California-specific risk factors, while mitigating the potential harms of universal screening such as an increase in false positive tests and health care costs.

Poor retention after closed reduction and cast immobilization of low-energy tibial shaft spiral fractures

BACKGROUND AND AIMS

The aim of this retrospective study was to analyze retention in cast after closed reduction of low-energy two-fragment tibial shaft fractures.

MATERIAL AND METHODS

The material consisted of 72 closed tibial shaft fractures AO/ ASIF type A treated with closed reduction and plaster cast. Fractures were subgrouped according to the AO/ASIF classification and the initial fracture displacement was measured. Final alignment and the frequency of operative intervention due to early loss of reduction were analyzed.

RESULTS

40% of all fractures lost reduction and were operated on. The largest subgroup was A1.2 fractures, a spiral tibial shaft fracture with a fibular fracture at another level. Out of the 28 fractures in this group 61% were converted from cast to early operative intervention.

CONCLUSION

Closed reduction and cast treatment of spiral tibial shaft fractures AO/ ASIF type A1.2 had a high failure rate.

Random and continuous-access immunoassays with chemiluminescent detection by Access automated analyzer

The Access Immunoassay System is an automated random and continuous-access analyzer for use with heterogeneous enzyme immunoassays. The instrument stores refrigerated reagent packs for as many as 24 different immunoassays. Throughput is 50-100 tests per hour. One- and two-step, and sandwich and competitive formats, each with various incubation times, can be accommodated, and sample sizes can vary from 10 to 200 microL. A paramagnetic microparticle solid phase combines with a chemiluminescent substrate for signal generation. Within-run CVs for noninfectious disease assays were 2.0% to 9.2%; total CVs were 3.4% to 11.1%. Regression analysis of method comparison studies with established procedures yielded slopes of 0.84 to 1.12 and correlation coefficients > or = 0.94 for 12 of 14 assays (range 0.83-0.99). Compared with culture methods, the Access assay for Chlamydia in urogenital specimens demonstrated sensitivity, specificity, and positive and negative predictive values of 90%, 99.7%, 95%, and 99%, respectively.

Random and continuous-access immunoassays with chemiluminescent detection by Access automated analyzer

The Access Immunoassay System is an automated random and continuous-access analyzer for use with heterogeneous enzyme immunoassays. The instrument stores refrigerated reagent packs for as many as 24 different immunoassays. Throughput is 50-100 tests per hour. One- and two-step, and sandwich and competitive formats, each with various incubation times, can be accommodated, and sample sizes can vary from 10 to 200 microL. A paramagnetic microparticle solid phase combines with a chemiluminescent substrate for signal generation. Within-run CVs for noninfectious disease assays were 2.0% to 9.2%; total CVs were 3.4% to 11.1%. Regression analysis of method comparison studies with established procedures yielded slopes of 0.84 to 1.12 and correlation coefficients > or = 0.94 for 12 of 14 assays (range 0.83-0.99). Compared with culture methods, the Access assay for Chlamydia in urogenital specimens demonstrated sensitivity, specificity, and positive and negative predictive values of 90%, 99.7%, 95%, and 99%, respectively.

Neuropeptides and classical transmitters. Localization and interaction

The present article briefly reviews some aspects on the localization and possible functional roles of neuropeptides. It is emphasized that a large number of peptides can be found in the nervous system and that they in many instances occur together with classical transmitters such as acetylcholine and catecholamines in the same neurons. In agreement, functional studies have revealed that they interact in different ways, both synergistically and antagonistically, with the transmitters. In some instances peptides may also have trophic effects. The recent cloning of neuronal peptide receptors has further substantiated a physiological role for these compounds in the nervous system. Moreover, the recent development of peptide antagonists, which pass the blood brain barrier, now opens up new possibilities to elucidate the functional role of neuropeptides and thus of the coexistence phenomenon.

Distribution of opioidergic, sympathetic and neuropeptide Y-positive nerves in the sphincter of Oddi and biliary tree of the monkey, Macaca fascicularis

The opioidergic, sympathetic and neuropeptide Y-positive innervation of the sphincter of Oddi (common bile duct sphincter and pancreatic duct sphincter), as well as other segments of the extrahepatic biliary tree was studied in the monkey by use of immunohistochemistry. Methionine-enkephalin-positive nerves were seen to innervate the smooth muscle of all portions of the sphincter of Oddi and also local ganglion cells. No methionine-enkephalin-positive nerves could be detected in the common bile duct, pancreatic duct or gallbladder. Tyrosine hydroxylase-positive nerves occurred between smooth muscle bundles and also ran to local ganglion cells as well as along the common bile duct. Neuropeptide Y-positive nerves were observed within smooth muscle of the sphincter of Oddi (all portions), common bile duct, pancreatic duct and gallbladder. No evidence of any differential innervation of the pancreatic duct and common bile duct sphincters could be detected with these markers.

Autoradiographic mapping of galanin receptors in the monkey brain

The distribution of specific binding sites for the peptide galanin was studied in the monkey brain by using 125I-galanin and the method of quantitative in vitro autoradiography. The binding to tissue sections was found to be rapid, reversible and saturable with a calculated Bmax of around 13 fmol mg-1 tissue in cortical regions and a KD ranging between 0.39 and 0.22 nM in different brain regions. Specifically bound 125I-galanin was detected in a number of brain regions throughout the rostrocaudal axis of the monkey brain. More specifically, the majority of the 125I-galanin binding sites were present in the basal forebrain (e.g. olfactory tubercle, lateral septal nuclei, nucleus accumbens, substantia innominata and the basal nucleus of Meynert), the amygdala (e.g. the lateral, medial accessory and central nuclei), the amygdala-hippocampal area, hypothalamus (e.g. the anterior hypothalamic area, the ventro-medial hypothalamus and the zona incerta), as well as in certain brain stem cell groups such as the substantia nigra (pars compacta), locus coeruleus, central grey substance, parabrachial nucleus, sensory and motor nuclei of the trigeminal nerve and the dorsal vagal complex. In the neocortex, highest binding density occurred in layer 4 of all neocortical fields, except in the visual cortex where the highest densities occurred in layers 4cb, 5a and 6. Major fibre tracts such as the fimbria and the stria terminalis also contained high densities of 125I-galanin binding sites. Areas poor in, or lacking, specific 125I-galanin binding sites included the basal ganglia, the thalamus, the mammillary bodies, the cerebellum, and the reticular formation of the brain stem. The pattern of galanin receptor distribution in the monkey brain reported here closely resembles that observed for galanin receptors and galanin-immunoreactive preterminal processes described previously in the rat brain. An exception, however, was neocortex, where in the rat neither 125I-galanin binding nor galanin-positive fibres have been observed. The present findings may indicate a close association between galanin receptors and nerve terminals containing galanin immunoreactivity in the monkey brain and implies important role(s) for galanin in neurotransmission in the monkey central nervous system.

Distribution of galanin-binding sites in the monkey and human telencephalon: preliminary observations

Using X-ray film autoradiography the distribution of 125I-galanin binding sites was studied in the forebrain of monkey and man. In the monkey a high density was found in all areas of the neocortex, especially layer 4, and in certain subfields in the hippocampal region. Also in the human brain high activity was seen in neocortex, mainly layer 6 and in hippocampal areas, as well as in amygdala, piriform cortex and hypothalamus. These results suggest that the 29-amino acid peptide galanin may be involved in the regulation of higher cortical functions in primates.

Autoradiographic quantitation and anatomical mapping of 125I-galanin binding sites in the rat central nervous system

The distribution of 125I-galanin binding sites in the rat central nervous system was studied by the use of autoradiography, and the amount of peptide bound was determined by the use of microdensitometry. The amount of 125I-galanin bound in various CNS regions ranged from non detectable to 0.40 pmol per gramme tissue at a concentration of 1.5 nM 125I-galanin. The anatomical mapping revealed high density of binding sites in the telencephalon, where labelling was seen in the entorhinal, perirhinal and piriform cortices, in most septal nuclei, in the amygdala and in the hippocampal formation. In the diencephalon binding sites were densely accumulated in the hypothalamus, including the median eminence and periventricular nucleus as well as in the dorsal and medial thalamic nuclei. In the mesencephalon binding sites were seen in many nuclei including the dorsal raphe nucleus, the periaqueductal central grey and pars compacta of the substantia nigra. The pons/medulla revealed high density of binding sites in the locus coeruleus, parabrachial nuclei and in the dorsal vagal complex, while binding in the spinal cord was seen in laminae I, II and X as well as in the intermediolateral horn. The distribution of 125I-galanin binding sites corresponded well to the localization of the peptide as revealed in several earlier immunohistochemical and radioimmunoassay studies, as well as to several previously reported effects of galanin on central autonomic functions.

Galanin impairs acquisition but not retrieval of spatial memory in rats studied in the Morris swim maze

The effect of intraventricular administration of the neuropeptide galanin on acquisition and retrieval in a modified Morris swim maze was studied in rats. Galanin induced a significant deficit in the acquisition of the task while no effects on the retrieval were observed. No deficits were seen 24 h after the last treatment. Galanin did not increase the number of failures to reach the platform. It is suggested that endogenous galanin modulates learning possibly via the galanin-containing cholinergic neurons in the septum-basal forebrain area projecting to the hippocampus and cortex.

Effects of galanin on 5-HT neurons in the rat CNS

Intraventricular injections of the neuropeptide galanin were shown to induce a significant increase of endogenous 5-hydroxyindoleacetic acid (5-HIAA) levels in the occipital cortex, hippocampus and median eminence of rats. A general, but in most regions non-significant, tendency for increased 5-hydroxytryptamine (5-HT) levels was also observed. In view of the similar effects of galanin on 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the median eminence and pons-medulla and in view of previous in vitro studies, these results are compatible with a presynaptic inhibitory effect of galanin on certain central 5-HT neurons of the rat.

Three-color immunofluorescence histochemistry allowing triple labeling within a single section

We describe a procedure for simultaneous immunohistochemical localization of three different neuropeptides, neurotransmitters, or neurotransmitter enzymes within one and the same tissue section and present a number of examples of its application within the brain and periphery. Primary antibodies from three different species were bound to three different neurochemical substances within the same section and were then reacted with three appropriate species-specific antisera conjugated with fluorescein, rhodamine/Texas red, or biotin. The biotinylated secondary antiserum was subsequently reacted with diethylaminocoumarin (DAMC) conjugated to avidin. This combination resulted in green, red, and blue fluorescent labeling of each antigen, respectively. Each fluorescent marker was viewed and photographed discretely using appropriate excitation and suppression filter combinations. The method is well suited for analyzing instances of multiple coexistence at both the level of the cell soma and within terminal regions. More broadly, the feasibility of three-color immunofluorescence histochemistry extends the range with which antigen localization can be used to investigate the morphological bases of relationships and interactions between immunohistochemically characterized neuronal elements.

Increase of galanin-like immunoreactivity in rat dorsal root ganglion cells after peripheral axotomy

The L4 and L5 dorsal root ganglia were studied in untreated rats and rats subjected to unilateral transection of the sciatic nerve, using the indirect immunofluorescence technique and antibodies to the peptide galanin (GAL). In control rats only low numbers of small ganglion cells contained GAL-like immunoreactivity (LI). After axotomy a marked increase in the number and intensity of GAL-immunoreactive ganglion cell bodies was seen on the lesion side. Thus, some primary sensory neurons react to transection of their peripheral branches by expressing increased GAL levels. A similar reaction has been described by other groups for vasoactive intestinal polypeptide.

Galanin-immunoreactive nerves in the rat iris: alterations induced by denervations

The iris and choroid membrane of the adult rat contain nerve fibers expressing immunoreactivity to the neuropeptide galanin. The density and distribution of galanin-positive nerve fibers varied from iris to iris and, particularly, among animals. Smooth, non-terminal axons were seen running in nerve bundles consisting of otherwise negative fibers. From the choroid membrane these bundles reached the iris via the ciliary body. Axons were frequently seen to branch giving rise to a sparse system of varicose, single fibers in the dilator plate and sphincter area. Galanin-positive fibers were sometimes also seen outlining blood vessels. Capsaicin, in a dose that causes permanent depletion of substance P- and cholecystokinin-immunoreactive fibers in the iris, caused no change in amount of galanin-positive fibers. Removal of the superior cervical ganglion caused a rapid and pronounced increase in the number of galanin-immunoreactive nerve fibers. Similarly, removal of the ciliary ganglion appeared to increase galanin immunoreactivity, while removal of the pterygopalatine ganglion was less effective. Lesioning of the trigeminal ganglion caused a disappearance of galanin immunoreactivity. The sympathectomy-induced increase was counteracted by capsaicin. Galanin-positive nerve cell bodies were present in both the superior cervical and the trigeminal ganglia. In the superior cervical ganglion, immunoreactive galanin did not seem to coexist with neuropeptide Y-positive cells; in the trigeminal ganglion, some galanin-positive cells also contained calcitonin gene-related peptide (CGRP) immunoreactivity, while most cells did not. In the iris, double-staining suggested that CGRP and galanin immunoreactivities were contained in different fiber populations.(ABSTRACT TRUNCATED AT 250 WORDS)

Galanin inhibits acetylcholine release in the ventral hippocampus of the rat: histochemical, autoradiographic, in vivo, and in vitro studies

A high density of galanin binding sites was found by using 125I-labeled galanin, iodinated by chloramine-T, followed by autoradiography in the ventral, but not in the dorsal, hippocampus of the rat. Lesions of the fimbria and of the septum caused disappearance of a major population of these binding sites, suggesting that a large proportion of them is localized on cholinergic nerve terminals of septal afferents. As a functional correlate to these putative galanin receptor sites, it was shown, both in vivo and in vitro, that galanin, in a concentration-dependent manner, inhibited the evoked release of acetylcholine in the ventral, but not in the dorsal, hippocampus. Intracerebroventricularly applied galanin (10 micrograms/15 microliters) fully inhibited the scopolamine (0.5 mg/kg, s.c.)-stimulated release of acetylcholine in the ventral, but not in the dorsal, hippocampus, as measured by microdialysis technique. In vitro, galanin inhibited the 25 mM K+-evoked release of [3H]acetylcholine from slices of the ventral hippocampus, with an IC50 value of approximately 50 nM. These results are discussed with respect to the colocalization of galanin- and choline acetyltransferase-like immunoreactivity in septal somata projecting to the hippocampus.

Effects of intraventricular injections of galanin on neuroendocrine functions in the male rat. Possible involvement of hypothalamic catecholamine neuronal systems

Galanin-catecholamine interactions have been analysed within the hypothalamus and the anteromedial frontal cortex of male rats by means of quantitative histofluorimetrical and biochemical measurements of catecholamine fluorescence in discrete catecholamine nerve terminal systems and measurements of serum levels of adenohypophyseal hormones and corticosterone using radio-immunoassay determinations. 125I-galanin binding sites were analysed and related to the distribution of galanin-immunoreactive neuronal structures in the median eminence and paraventricular hypothalamic nucleus. The results show that intraventricular injections of galanin in the awake and unrestrained male rat produce rapid increases of prolactin and growth hormone secretion but no effects on serum luteinizing hormone, thyroid stimulating hormone or on corticosterone levels. These changes in neuroendocrine function were associated with a selective reduction of the catecholamine stores in the medial palisade zone of the median eminence at the 20 min time interval. 125I-galanin binding sites were found throughout the hypothalamus including the median eminence and the magnocellular part of the paraventricular hypothalamic nucleus with a good correspondence with galanin immuno-reactivity. It is suggested that the enhancement of prolactin secretion induced by galanin involves an interaction between galanin and dopamine in the medial palisade zone leading to a reduced synthesis and/or release of dopamine and thus to a reduced prolactin inhibitory activity and to increases in prolactin secretion. A possible involvement of hypothalamic catecholamines in the galanin-induced changes of growth hormone secretion remains to be established.

Coexistence of peptides with classical neurotransmitters

In the present article the fact is emphasized that neuropeptides often are located in the same neurons as classical transmitters such as acetylcholine, 5-hydroxy-tryptamine, catecholamines, gamma-aminobutyric acid (GABA) etc. This raises the possibility that neurons produce, store and release more than one messenger molecule. The exact functional role of such coexisting peptides is often difficult to evaluate, especially in the central nervous system. In the periphery some studies indicate apparently meaningful interactions of different types with the classical transmitter, but other types of actions including trophic effects have been observed. More recently it has been shown that some neurons contain more than one classical transmitter, e.g. 5-HT plus GABA, further underlining the view that transfer of information across synapses may be more complex than perhaps hitherto assumed.

Immunohistochemical evidence for a spinothalamic pathway co-containing cholecystokinin- and galanin-like immunoreactivities in the rat

Using indirect immunofluorescence technique combined with retrograde tracing as well as surgical lesions, a system of spinothalamic neurons containing both galanin- and cholecystokinin-like immunoreactivity has been defined. The cell bodies are located in the lumbar segments L1-L5 with a preferential localization dorsal to the central canal at rostral levels and lateral to the canal at caudal levels. The cells project via the ventral part of the lateral funiculus to the most ventral and posterior parts of thalamus. Here a distinct, varicose terminal network was seen extending caudally from an area lateral to the medial lemniscus, running medially over the medial lemniscus, traversing the parafascicular nucleus and running dorsal to the fasciculus retroflexus into the periventricular gray matter. Transection of various parts of the spinal cord as well as retrograde tracing experiments indicate that the spinothalamic galanin cholecystokinin system represents a crossed pathway. The present results demonstrate that a spinothalamic system can be characterized by its content of galanin- and cholecystokinin-like peptides, two putative messenger molecules. It is only a minor component of the total spinothalamic projection.

Evidence for an inhibitory effect of the peptide galanin on dopamine release from the rat median eminence

The role of the neuropeptide galanin (GAL) in rat hypothalamus has been studied in different experimental models. Thus, the effect of GAL on potassium-induced dopamine release was analyzed in vitro, and the localization of GAL and GAL binding sites was studied with immunohistochemistry and receptor autoradiography, respectively. In the median eminence GAL and presumably dopamine were found to coexist in nerve endings and this area contained a high density of 125I-GAL binding sites. In vitro experiments revealed that GAL inhibited the release of [3H]dopamine in a dose-dependent manner (IC50 = 7-10 nM), possibly via a presynaptic receptor.

Coexistence of galanin-like immunoreactivity with catecholamines, 5-hydroxytryptamine, GABA and neuropeptides in the rat CNS

The coexistence of galanin (GAL)-like immunoreactivity (LI) with markers for catecholamines, 5-hydroxytryptamine (5-HT), GABA, or some neuropeptides was mapped in the rat CNS by using adjacent sections, as well as by elution-restaining and double-labeling immunocytochemistry. Many instances of coexistence were observed, but there were also numerous GAL-positive cell body populations displaying distributions similar to those of these markers but without apparent coexistence. In the hypothalamic arcuate nucleus GAL-LI was found in a large proportion of tyrosine hydroxylase (TH)-positive cell bodies (A12 cells), both in the dorsomedial and ventrolateral subdivisions, with a higher number in the latter. GAL-LI coexisted in glutamic acid decarboxylase (GAD)-positive somata in the posterior aspects of the arcuate nucleus and at all rostrocaudal levels in fibers in the external layer of the median eminence. In the anterior hypothalamus, a large population of the cells of the parvocellular and magnocellular paraventricular nuclei contained both GAL-LI and vasopressin-LI. Moreover, somata containing both GAD- and GAL-LI were seen lateral to the mammillary recess in the tuberal and caudal magnocellular nuclei. Some of the neurons of the caudal group were shown to project to the occipital cortex using combined retrograde tracing and immunofluorescence. With regard to mesencephalic and medullary catecholamine neurons, GAL-LI coexisted in a large proportion of the noradrenergic locus coeruleus somata (A6 cell group) and in the A4 group dorsolateral to the fourth ventricle, as well as in the caudal parts of the A2 group in the dorsal vagal complex. However, in more rostral parts of the latter, especially in the medial subdivision of the solitary tract nucleus, a very large population of GAL-IR small cell bodies was seen intermingling with catecholamine neurons, but they did not contain TH-LI. Furthermore, GAL-IR cell bodies coextensive with, but not coexisting in, TH-IR somata were seen in the C1 (epinephrine) horea in the ventrolateral medulla at the level of area postrema and in the most rostral aspects of the C1 group. Finally, 5-HT-positive cell bodies of the mesencephalic and medullary raphe nuclei and a subpopulation of coarse 5-HT nerve fibers in the hippocampus co-contained GAL-LI. The present results demonstrate that a GAL-like peptide is present in many systems containing other neuroactive compounds, including dopamine, norepinephrine, 5-HT, GABA, and vasopressin.(ABSTRACT TRUNCATED AT 400 WORDS)

Galanin-like immunoreactivity in hippocampal afferents in the rat, with special reference to cholinergic and noradrenergic inputs

The distribution of galanin-like immunoreactivity in the rat hippocampal formation (hippocampus and dentate gyrus) was studied and its origins were determined using various lesioning techniques. Special reference was made to the known cholinergic and noradrenergic hippocampal inputs from the septum-basal forebrain complex and locus coeruleus, both of which have previously been shown to co-contain galanin-like immunoreactivity at the cell body level. Galanin-immunoreactive fibers in the hippocampal formation were of at least three different morphological types: (1) Fine, slender, faintly immunoreactive fibers were seen throughout the hippocampal formation. (2) A strongly fluorescent varicose fiber population was observed mainly in the strata radiatum and oriens of the ventral CA3 region. (3) A population of fine, faint puncta was seen within the granule and pyramidal cell layers throughout the hippocampal formation. Knife cut lesions of the dorsal afferent pathways resulted in almost complete disappearance of all fiber types, except for the ventral fine fibers. Lesions of the fimbria affected mainly the coarse and punctate fiber types, while lesions of the supracallosal striae depleted mainly the fine fibers. Cuts anterior and ventral to the hippocampal formation caused a decrease in ventral fine fibers. Furthermore, lesions of the dorsal bundle caused an almost complete disappearance of the fine fibers in all regions of the hippocampal formation. Neurotoxin lesions of the diagonal band/septal complex resulted in decreases in faintly immunoreactive puncta within the granule cell layer and adjacent fine fibers. It is concluded that most fine galanin-positive fibers originate in the lower brain stem, presumably the locus coeruleus, and appear to reach the hippocampal formation primarily through the supracallosal striae and the ventral route. The fimbria seems to contain a large proportion of the fibers giving rise to the coarse strongly fluorescent innervation, which appears to originate rostral to the pons. The galanin-immunoreactive fibers originating in cholinergic somata of the diagonal band, medial septal nuclei, previously shown to project to the hippocampal formation, seem to give rise to faintly labeled puncta within the granule and pyramidal cell layers, and to a small proportion of the fine fibers bordering the cell layers, as revealed by immunohistochemistry using our antibody.(ABSTRACT TRUNCATED AT 400 WORDS)

A galanin-like peptide coexists in putative cholinergic somata of the septum-basal forebrain complex and in acetylcholinesterase-containing fibers and varicosities within the hippocampus in the owl monkey (Aotus trivirgatus)

The putative cholinergic neurons of the basal forebrain and fibers in the hippocampus were studied in relation to galanin (GAL)-like immunoreactivity (LI) in the owl monkey by the use of acetylcholinesterase (AChE) histochemistry in combination with immunocytochemistry. Virtually all of the AChE-reactive somata within the medial septal nucleus, diagonal band and nucleus basalis and hippocampal AChE reactive fibers and varicosities co-contained GAL-LI. The more extensive distribution of GAL-like peptide in the cholinergic forebrain of the monkey (as compared to the rat) may reflect an increased importance of this peptide(s) in cotransmission processes in this region in higher animals.

Distribution of galaninlike immunoreactivity in the rat central nervous system

The localization of galanin (GAL) immunoreactive (IR) neuronal structures in the rat central nervous system has been investigated by using the indirect immunofluorescence technique. GAL-IR structures were seen in high concentrations in the hypothalamus, medulla oblongata, and spinal cord. Less extensive systems were detected in the telencephalon, thalamus, mesencephalon, and pons, while virtually no GAL-positive structures were seen in the olfactory bulb and cerebellum. Major populations of cell bodies staining for GAL-like material were seen in many areas. In the telencephalon somata were revealed in the bed nucleus of stria terminalis, in the nucleus of the diagonal band, medial septum, and in the medial aspects of the central amygdaloid nucleus, and in small numbers in cortical areas. The anterodorsal and periventricular nuclei of the thalamus contained positive cell bodies. In the hypothalamus GAL-IR somata were seen in the medial and lateral preoptic nuclei, arcuate nucleus, periventricular nucleus, in the dorsomedial nucleus, in the medial forebrain bundle area, in the tubular, caudal, accessory, supraoptic, and paraventricular magnocellular nuclei and lateral to the mammillary recess. The dorsal raphe nucleus hosted a large number of GAL-positive somata. Locus coeruleus of the pons contained a large number of GAL-IR perikarya. In the medulla oblongata positive somata were found in the caudal spinal trigeminal nucleus, the nucleus of the solitary tract, and in the ventral lateral area just rostral to area postrema. Small cell bodies were detected in the superficial layers of the dorsal horn of the spinal cord at all levels and in lamina X at lumbar levels. Analysis of GAL-positive fibers in the telencephalon revealed highly or medium-dense networks in the lateral septal nucleus, in the bed nucleus of stria terminalis, and in the central and medial amygdaloid nuclei. Positive fibers were found in the thalamus in and around the periventricular nucleus as well as in the lateral habenular nucleus and extending in a lateral, caudal direction from the third ventricle and fasciculus retroflexus to the lateral tip of the medial lemniscus. In the hypothalamus the external layer of the median eminence contained a very dense fiber network. Dense or medium-dense GAL-IR networks were detected in the periventricular nucleus, throughout the medial and lateral preoptic areas, in the medial forebrain bundle area, in the dorsomedial nucleus, and lateral to the mammillary recess. In the pons GAL-IR fibers were seen in the parabrachial nuclei, dorsal to the superior olive, and in the periaqueductal central gray.(ABSTRACT TRUNCATED AT 400 WORDS)

The hypothalamic arcuate nucleus-median eminence complex: immunohistochemistry of transmitters, peptides and DARPP-32 with special reference to coexistence in dopamine neurons

In this paper, we describe the results of a series of experiments which have examined the distribution within the arcuate nucleus of the hypothalamus of neurons containing the following immunoreactivities: TH-LI, GAD-LI, NT-LI, GAL-LI, GRF-LI, Met-ENK-LI, Leu-ENK-LI, Met-ENK-7-LI, Met-ENK-8-LI, metorphamide-LI, DYN-LI, NPY-LI, SOM-LI, FMRFamide-LI, and CLIP-LI and ependymal tanycytes containing DARPP-32-LI. Using elution-restaining and double antibody staining techniques we have established numerous patterns of coexistence of these various neurotransmitters and neuropeptides. Thus, neurons containing TH-LI were, in some instances, also found to contain GAD-LI, NT-LI, GAL-LI, GRF-LI, Met-ENK-8-LI, Leu-ENK-LI, or DYN-LI or combinations of these compounds. For example, some TH-IR neurons also contained GAL-LI and GRF-LI, while other TH-IR. neurons were also seen to contain GRF- and NT-LI. These neurons may, in fact, contain even more compounds. NPY-IR neurons and those containing SOM-LI and CLIP-LI were distinct and separate from those containing TH-LI. The distribution of these different neurochemical types of neurons and their patterns of coexistence are summarized in Fig. 34, while the relative distribution patterns of immunoreactive fibres in the median eminence are summarized in Fig. 35.

Galanin-like immunoreactivity in cholinergic neurons of the septum-basal forebrain complex projecting to the hippocampus of the rat

It is now well recognized that there are several groups of cholinergic neurons in the basal forebrain with direct projections to various cortical regions. Immunohistochemical investigations of the distribution of the neuropeptide galanin (GAL) have shown that two of these brain areas, the medial septum and diagonal band, contained large numbers of GAL-immunoreactive neurons. In the present study, double staining techniques using antibodies raised against choline acetyltransferase (ChAT) revealed that GAL- and ChAT-like immunoreactivities are colocalized within a subpopulation of the cholinergic neurons within the medial septum and diagonal band. This colocalization of GAL- and ChAT-immunoreactivities was not seen to occur within other groups of forebrain cholinergic neurons. Immunohistochemistry carried out subsequent to injections of fluorescent retrograde tracers into the hippocampal formation revealed that both ChAT/GAL- and ChAT-containing neurons project to the hippocampal formation. The question of GAL as a modulator of cholinergic transmission in this projection is discussed.

Distribution of galanin-like immunoreactivity in the gastro-intestinal tract of several mammalian species

The distribution of galanin-immunoreactive (GAL-IR) neurons was mapped in detail in the gastro-intestinal tract of the rat, mouse, guinea-pig and pig by use of the indirect immunofluorescence technique. GAL-IR cell bodies were found in both the submucous and the myenteric plexus, with considerably higher numbers in the former ganglia. The largest number of GAL-IR perikarya was seen in the duodenal submucous plexus of the pig. With some (single) exceptions, GAL-IR cell somata were not observed in the myenteric plexus of the pig and guinea-pig, and in the submucous plexus of the esophagus and the stomach of the guinea-pig. GAL-IR fibers occurred in most parts of the gastro-intestinal tract. In the lamina propria a few non-varicose, weakly fluorescent fibers were noted in the mouse and rat, whereas in the pig and guinea-pig were large numbers of GAL-IR fibers with a varicose appearance was observed. These fibers were in all species most numerous in the distal portion of the intestinal tract. In the submucosa GAL-IR fibers were detected in all four species, and in the pig and guinea-pig some fibers surrounded blood vessels. A large number of GAL-IR fibers was generally seen in the circular smooth muscle layer, except in the guinea-pig, which only seemed to contain a few fibers. In the longitudinal muscle layer only single fibers could be detected. However, the gastric fundus region of the pig contained a moderate number of fibers in the longitudinally and obliquely oriented layers. In general, in the rat, mouse and pig, the submucous and myenteric plexus contained moderate or large numbers of GAL-IR fibers. In the guinea-pig, no or only single fibers were observed in the plexus of the upper gastro-intestinal tract and the rectum, while moderate numbers were seen in the ileum and colon. Thin adjacent sections stained for vasoactive intestinal polypeptide (VIP) and GAL revealed the coexistence of these two peptides in cell bodies of the myenteric plexus in the pig duodenum and guinea-pig colon. In these two species the GAL- and VIP-nerve fiber networks also exhibited marked similarities. However, in the rat and mouse VIP- and GAL-distribution patterns were in general different. The present findings indicate the presence of yet another neuropeptide or peptide family in the gastro-intestinal tract of several rodents and the pig.

A galanin-like peptide in the central nervous system and intestine of the rat

Galanin (GAL), a 29 amino acid peptide, was recently isolated from the small intestine of pigs. In the present study an antiserum towards porcine GAL has been developed and used for radioimmunoassay and immunohistochemical studies. We now report that GAL-like immunoreactivity occurs in wide-spread systems in the rat CNS and intestine.