Alternative treatment of gallbladder disease.

Major risk factors for gallbladder disease include a sedentary lifestyle and a diet rich in refined sugars. In genetically prone individuals, these two factors lead to an abnormal bile composition, altered gut microflora, and hyperinsulinemia, with resulting gallstone formation. As a large percentage of gallbladder patients have continued digestive complaints following cholecystectomy, the author examines complementary and alternative medicine (CAM) treatments to counteract gallstone formation. Herbal medicine such as turmeric, oregon grape, bupleurum, and coin grass may reduce gallbladder inflammation and relieve liver congestion. Elimination of offending foods, not necessarily 'fatty' foods, is often successful and recommended by many holistic physicians. Regular aerobic exercise has a beneficial effect on hyperinsulinemia, which is often associated with gallbladder disease. Dietary changes that lower plasma insulin levels, such as a change in dietary fats and substitution of unrefined carbohydrates for refined carbohydrates, may also be helpful.

Androgen receptor-immunoreactivity in the forebrain of the Eastern Fence lizard (Sceloporus undulatus).

Androgen receptor (AR) distribution in the lizard forebrain and optic tectum was examined using PG21 immunohistochemistry. In the male Eastern Fence lizard, AR-immunoreactive (-ir) nuclei were observed in the medial preoptic area, ventromedial and arcuate hypothalamic nuclei, periventricular hypothalamus, premammillary nucleus, bed nucleus of the stria terminalis, and ventral posterior amygdala. Punctate immunostaining of neuronal processes (axons and/or dendrites) was concentrated in the cortex, hypothalamus, and optic tectum. AR-ir nuclei in the female brain were confined to the ventral posterior amygdala and ventromedial hypothalamic nucleus. The AR distribution in the lizard brain is similar to that reported for other vertebrate classes. Sex differences in AR-immunoreactivity may contribute to sex-specific behaviors in the Eastern Fence lizard.

Efferent projections of the intergeniculate leaflet and the ventral lateral geniculate nucleus in the rat.

The intergeniculate leaflet (IGL) and the ventral lateral geniculate nucleus (VLG) are ventral thalamic derivatives within the lateral geniculate complex. In this study, IGL and VLG efferent projections were compared by using anterograde transport of Phaseolus vulgaris-leucoagglutinin and retrograde transport of FluoroGold. Projections from the IGL and VLG leave the geniculate in four pathways. A dorsal pathway innervates the thalamic lateral dorsal nucleus (VLG), the reuniens and rhomboid nuclei (VLG and IGL), and the paraventricular nucleus (IGL). A ventral pathway runs through the geniculohypothalamic tract to the suprachiasmatic nucleus and the anterior hypothalamus (IGL). A medial pathway innervates the zona incerta and dorsal hypothalamus (VLG and IGL); the lateral hypothalamus and perifornical area (VLG); and the retrochiasmatic area (RCA), dorsomedial hypothalamic nucleus, and subparaventricular zone (IGL). A caudal pathway projects medially to the posterior hypothalamic area and periaqueductal gray and caudally along the brachium of the superior colliculus to the medial pretectal area and the nucleus of the optic tract (IGL and VLG). Caudal IGL axons also terminate in the olivary pretectal nucleus, the superficial gray of the superior colliculus, and the lateral and dorsal terminal nuclei of the accessory optic system. Caudal VLG projections innervate the lateral posterior nucleus, the anterior pretectal nucleus, the intermediate and deep gray of the superior colliculus, the dorsal terminal nucleus, the midbrain lateral tegmental field, the interpeduncular nucleus, the ventral pontine reticular formation, the medial and lateral pontine gray, the parabrachial region, and the accessory inferior olive. This pattern of IGL and VLG projections is consistent with our understanding of the distinct functions of each of these ventral thalamic derivatives.

192 IgG-saporin abolishes p75 neurotrophin receptor immunoreactivity in rat SCN.

The rat suprachiasmatic (SCN) contains a dense plexus of low-affinity p75 neurotrophin receptor (p75NTR)-immunoreactivity. In some SCN neurons, p75NTR is co-localized with vasoactive intestinal peptide (VIP). The present study examines the effect of third ventricle administration of 192 IgG-saporin immunotoxin on p75NTR and VIP immunoreactivity in the rat SCN. The 192 IgG-saporin immunotoxin abolished p75NTR immunoreactivity in the SCN. VIP immunoreactivity in the SCN of saporin-lesioned animals was not significantly different from that of control animals. Immunolesions of the p75NTR-ir cell population in the SCN may prove useful in clarifying the role of p75NTR in circadian timing.

Delayed loss of p75 neurotrophin receptor-immunoreactivity in the rat suprachiasmatic nucleus and intergeniculate leaflet after binocular enucleation.

The rat suprachiasmatic nucleus (SCN) contains a dense plexus of low-affinity p75 neurotrophin receptor (p75NTR)-immunoreactivity. Scattered patches of p75NTR immunoreactivity are present in the intergeniculate leaflet (IGL). Both SCN and IGL receive a direct retinal input. After binocular enucleation, there is a delayed loss of p75NTR-immunoreactivity in the SCN and IGL beginning at, respectively, 4 and 8 weeks post-enucleation, with complete loss occurring in both nuclei by week 12. This delayed loss may be due to an up-regulation of growth factor secretion by local cells in response to retinal axon degeneration.

Organization of neural inputs to the suprachiasmatic nucleus in the rat.

The circadian timing of the suprachiasmatic nucleus (SCN) is modulated by its neural inputs. In the present study, we examine the organization of the neural inputs to the rat SCN using both retrograde and anterograde tracing methods. After Fluoro-Gold injections into the SCN, retrogradely labeled neurons are present in a number of brain areas, including the infralimbic cortex, the lateral septum, the medial preoptic area, the subfornical organ, the paraventricular thalamus, the subparaventricular zone, the ventromedial hypothalamic nucleus, the posterior hypothalamic area, the intergeniculate leaflet, the olivary pretectal nucleus, the ventral subiculum, and the median raphe nuclei. In the anterograde tracing experiments, we observe three patterns of afferent termination within the SCN that correspond to the photic/raphe, limbic/hypothalamic, and thalamic inputs. The median raphe projection to the SCN terminates densely within the ventral subdivision and sparsely within the dorsal subdivision. Similarly, areas that receive photic input, such as the retina, the intergeniculate leaflet, and the pretectal area, densely innervate the ventral SCN but provide only minor innervation of the dorsal SCN. A complementary pattern of axonal labeling, with labeled fibers concentrated in the dorsal SCN, is observed after anterograde tracer injections into the hypothalamus and into limbic areas, such as the ventral subiculum and infralimbic cortex. A third, less common pattern of labeling, exemplified by the paraventricular thalamic afferents, consists of diffuse axonal labeling throughout the SCN. Our results show that the SCN afferent connections are topographically organized. These hodological differences may reflect a functional heterogeneity within the SCN.

p75 neurotrophin receptor immunoreactivity in the aged human hypothalamus.

Low-affinity p75 neurotrophin receptor (p75NTR) immunoreactivity in the aged human hypothalamus was examined in autopsied material. Numerous p75NTR-immunoreactive cells were found in the paraventricular and supraoptic hypothalamic nuclei. The suprachiasmatic nucleus was devoid of p75NTR-immunostaining. Many p75NTR-immunoreactive fibers extended laterally and ventrally from the paraventricular and supraoptic nuclei into the pituitary stalk and median eminence. Our results suggest that neurotrophins may be present within the human hypothalamo-hypophyseal system.

Magnetohydrodynamic wave resonance and the evocation of epileptiform activity by millitesla DC magnetic fields.

DC magnetic fields of low- to medium-flux density (nTesla to mTesla) affect a variety of brain activities. The cellular mechanism underlying these effects is unknown. A model involving magnetohydrodynamic waves and corresponding resonance phenomena is offered here as a solution. The model is discussed in relation to the evocation of epileptiform activity due to external DC magnetic fields in the mTesla range. The assumed existence of a resonance wave makes it possible to calculate the size of the involved area.

Putative excitatory amino acid projections to the suprachiasmatic nucleus in the rat.

Retrograde axonal transport of the select neuronal tracer [3H]D-aspartate was used to demonstrate possible sources of excitatory input to the suprachiasmatic nucleus (SCN) in the albino rat. Following injection of [3H]D-aspartate into the SCN, neurons were retrogradely labeled in the infralimbic cortex, the lateral septal nucleus, the paraventricular thalamic nucleus, the medial preoptic area, the ventromedial, dorsomedial and posterior hypothalamic nuclei, the zona incerta, the intergeniculate leaflet and the ventral subiculum. Retinal ganglion cells, which project to the SCN and use glutamate as a neurotransmitter, were not labeled in our [3H]D-aspartate experiments, demonstrating a limitation of this method (i.e., false negatives). Our results show that the [3H]D-aspartate neuronal tracer labels a subset of areas known to project to the SCN, indicating these areas as likely sources of excitatory input to the SCN.

Efferent projections of the paraventricular thalamic nucleus in the rat.

The paraventricular nucleus of the thalamus (PVT) receives input from all major components of the circadian timing system, including the suprachiasmatic nucleus (SCN), the intergeniculate leaflet and the retina. For a better understanding of the role of this nucleus in circadian timing, we examined the distribution of its efferent projections using the anterograde tracer Phaseolus vulgaris leucoagglutinin (PHA-L). The efferent projections of the PVT are loosely organized along its dorsal-ventral and anterior-posterior axes. The anterior PVT sends projections to the SCN; the dorsomedial and ventromedial hypothalamic nuclei; the lateral septum; the bed nucleus of the stria terminalis; the central and basomedial amygdaloid nuclei; the anterior olfactory nucleus; the olfactory tubercle; the nucleus accumbens; the infralimbic, piriform, and perirhinal cortices; the ventral subiculum; and the endopiriform nucleus. A small PHA-L injection, restricted to the ventral portion of the anterior PVT, produces a similar pattern of labeling, except for a marked decrease in the number of labeled fibers in the hypothalamus, cortex, and lateral septum and an increase in labeling in the endopiriform nucleus and basolateral amygdaloid nucleus. The posterior PVT has a more limited efferent distribution than the anterior PVT, terminating in the anterior olfactory nucleus; the olfactory tubercle; the nucleus accumbens; and the central, basolateral, and basomedial nuclei of the amygdala. Our results show that the anterior PVT is ideally situated to relay circadian timing information from the SCN to brain areas involved in visceral and motivational aspects of behavior and to provide feedback regulation of the SCN.

Neuropeptide-immunoreactive neurons projecting to the paraventricular hypothalamic nucleus in the rat.

The paraventricular nucleus of the hypothalamus (PVH) is innervated by a variety of types of neuropeptide-immunoreactive fibers. The cells of origin for many of these inputs are not known. In the present study, the combined retrograde fluorescence-immunofluorescence method was used to determine the cells of origin for neurotensin-, corticotropin-releasing factor-, brain natriuretic peptide-, somatostatin-, and met-enkephalin-like immunoreactive (-ir) fibers in the PVH. After injections of the fluorescent tracer Fluorogold into the PVH, the pattern of retrograde labeling was as previously reported (Sawchenko and Swanson, 1983, J. Comp. Neurol. 218:121-144; McKellar and Loewy, 1981, Brain Res. 217:351-357). The distribution of each type of double-labeled neuron was unique. Retrogradely labeled enkephalin-ir neurons were concentrated in two locations: the ventral part of the lateral septal nucleus and the lateral anterior nucleus within the AHA. A small cluster of corticotropin-releasing factor-ir neurons in the ventral lateral subnucleus of the bed nucleus of the stria terminalis were retrogradely labeled. Notable concentrations of somatostatin-ir double-labeled neurons were found in the ventral part of the lateral hypothalamic area and the medial part of the arcuate hypothalamic nucleus. Neurotensin-ir double-labeled neurons were most numerous in the anteroventral periventricular nucleus and in the retrochiasmatic area. Many brain natiuretic peptide-ir neurons in the tuberomammillary nucleus of the hypothalamus and in the pedunculopontine and laterodorsal tegmental nuclei were retrogradely labeled. The specificity of these chemically defined projections helps lay the groundwork for examining the functional organization of PVH afferents.

Efferent projections of the infralimbic cortex of the rat.

On the basis of stimulation studies, it has been proposed that the infralimbic cortex (ILC), Brodmann area 25, may serve as an autonomic motor cortex. To explore this hypothesis, we have combined anterograde tracing with Phaseolus vulgaris leucoagglutinin (PHA-L) and retrograde tracing with wheat germ aggutinin conjugated to horseradish peroxidase (WGA-HRP) to determine the efferent projections from the ILC. Axons exit the ILC in one of three efferent pathways. The dorsal pathway ascends through layers III and V to innervate the prelimbic and anterior cingulate cortices. The lateral pathway courses through the nucleus accumbens to innervate the insular cortex, the perirhinal cortex, and parts of the piriform cortex. In addition, some fibers from the lateral pathway enter the corticospinal tract. The ventral pathway is by far the largest and innervates the thalamus (including the paraventricular nucleus of the thalamus, the border zone between the paraventricular and medial dorsal nuclei, and the paratenial, reuniens, ventromedial, parafasicular, and subparafasicular nuclei), the hypothalamus (including the lateral hypothalamic and medial preoptic areas, and the suprachiasmatic, dorsomedial, and supramammillary nuclei), the amygdala (including the central, medial, and basomedial nuclei, and the periamygdaloid cortex) and the bed nucleus of the stria terminalis. The ventral efferent pathway also provides descending projections to autonomic cell groups of the brainstem and spinal cord including the periaqueductal gray matter, the parabrachial nucleus, the nucleus of the solitary tract, the dorsal motor vagal nucleus, the nucleus ambiguus, and the ventrolateral medulla, as well as lamina I and the intermediolateral column of the spinal cord. The ILC has extensive projections to central autonomic nuclei that may subserve a role in modulating visceral responses to emotional stimuli, such as stress.

Organization of cortical, basal forebrain, and hypothalamic afferents to the parabrachial nucleus in the rat.

In a previous study (Herbert et al., J. Comp. Neurol. [1990];293:540-580), we demonstrated that the ascending afferent projections from the medulla to the parabrachial nucleus (PB) mark out functionally specific terminal domains within the PB. In this study, we examine the organization of the forebrain afferents to the PB. The PB was found to receive afferents from the infralimbic, the lateral prefrontal, and the insular cortical areas; the dorsomedial, the ventromedial, the median preoptic, and the paraventricular hypothalamic nuclei; the dorsal, the retrochiasmatic, and the lateral hypothalamic areas; the central nucleus of the amygdala; the substantia innominata; and the bed nucleus of the stria terminalis. In general, forebrain areas tend to innervate the same PB subnuclei from which they receive their input. Three major patterns of afferent termination were noted in the PB; these corresponded to the three primary sources of forebrain input to the PB: the cerebral cortex, the hypothalamus, and the basal forebrain. Hypothalamic afferents innervate predominantly rostral portions of the PB, particularly the central lateral and dorsal lateral subnuclei. The basal forebrain projection to the PB ends densely in the external lateral and waist subnuclei. Cortical afferents terminate most heavily in the caudal half of the PB, particularly in the ventral lateral and medial subnuclei. In addition, considerable topography organization was found within the individual projections. For example, tuberal lateral hypothalamic neurons project heavily to the central lateral subnucleus and lightly to the waist area; in contrast, caudal lateral hypothalamic neurons send a moderately heavy projection to both the central lateral and waist subnuclei. Our results show that the forebrain afferents of the PB are topographically organized. These topographical differences may provide a substrate for the diversity of visceral functions associated with the PB.

Neuropeptide organization of the hypothalamic projection to the parabrachial nucleus in the rat.

The hypothalamus is a major source of afferents to the parabrachial nucleus (PB), but the neurotransmitters in this pathway are largely unknown. In this study, we examine the neuropeptide immunoreactivities of neurons in the hypothalamus that project to the PB by using the combined retrograde fluorescence-immunofluorescence method. After injections of the fluorescent tracer fast blue into the PB, retrogradely labeled neurons were observed in the paraventricular, dorsomedial, ventromedial, median preoptic, and anteroventral periventricular hypothalamic nuclei; in the dorsal, retrochiasmatic, and lateral hypothalamic areas; and in the medial and lateral preoptic areas. Our results show that at least five distinct neuropeptide-immunoreactive cell populations in the hypothalamus project to the PB. In the perifornical lateral hypothalamus, many neurotensin (NT)-, corticotropin-releasing factor-, dynorphin (DYN)-, angiotensin II (AII)-, and galanin-like immunoreactive (-ir) neurons were retrogradely labeled. A cluster of retrogradely labeled neurons in the juxtacapsular lateral hypothalamus stained with an antiserum against alpha-melanocyte stimulating hormone (alpha MSH). Over 50% of the retrogradely labeled cells in the arcuate nucleus were adrenocorticotropin (ACTH)-or alpha MSH-ir. Many alpha MSH- and ACTH-ir, and a few DYN-, NT- and AII-ir neurons in the retrochiasmatic area were retrogradely labeled. Only small numbers of double-labeled neurons were found in the paraventricular nucleus, and, of these, enkephalin-ir and dynorphin-ir neurons were the most common. Somatostatin-ir cells in the hypothalamus were rarely double-labeled. The chemical coding of these hypothalamic projections to the PB may provide important clues to the functional organization of these descending pathways.

Connections of the parabrachial nucleus with the nucleus of the solitary tract and the medullary reticular formation in the rat.

We examined the subnuclear organization of projections to the parabrachial nucleus (PB) from the nucleus of the solitary tract (NTS), area postrema, and medullary reticular formation in the rat by using the anterograde and retrograde transport of wheat germ agglutinin-horseradish peroxidase conjugate and anterograde tracing with Phaseolus vulgaris-leucoagglutinin. Different functional regions of the NTS/area postrema complex and medullary reticular formation were found to innervate largely nonoverlapping zones in the PB. The general visceral part of the NTS, including the medial, parvicellular, intermediate, and commissural NTS subnuclei and the core of the area postrema, projects to restricted terminal zones in the inner portion of the external lateral PB, the central and dorsal lateral PB subnuclei, and the "waist" area. The dorsomedial NTS subnucleus and the rim of the area postrema specifically innervate the outer portion of the external lateral PB subnucleus. In addition, the medial NTS innervates the caudal lateral part of the external medial PB subnucleus. The respiratory part of the NTS, comprising the ventrolateral, intermediate, and caudal commissural subnuclei, is reciprocally connected with the Kölliker-Fuse nucleus, and with the far lateral parts of the dorsal and central lateral PB subnuclei. There is also a patchy projection to the caudal lateral part of the external medial PB subnucleus from the ventrolateral NTS. The rostral, gustatory part of the NTS projects mainly to the caudal medial parts of the PB complex, including the "waist" area, as well as more rostrally to parts of the medial, external medial, ventral, and central lateral PB subnuclei. The connections of different portions of the medullary reticular formation with the PB complex reflect the same patterns of organization, but are reciprocal. The periambiguus region is reciprocally connected with the same PB subnuclei as the ventrolateral NTS; the rostral ventrolateral reticular nucleus with the same PB subnuclei as both the ventrolateral (respiratory) and medial (general visceral) NTS; and the parvicellular reticular area, adjacent to the rostral NTS, with parts of the central and ventral lateral and the medial PB subnuclei that also receive rostral (gustatory) NTS input. In addition, the rostral ventrolateral reticular nucleus and the parvicellular reticular formation have more extensive connections with parts of the rostral PB and the subjacent reticular formation that receive little if any NTS input. The PB contains a series of topographically complex terminal domains reflecting the functional organization of its afferent sources in the NTS and medullary reticular formation.

Bed nucleus of the stria terminalis: cytoarchitecture, immunohistochemistry, and projection to the parabrachial nucleus in the rat.

The bed nucleus of the stria terminalis (BST) sends a dense projection to the parabrachial nucleus (PB) in the pons. The BST contains many different types of neuropeptidelike immunoreactive cells and fibers, each of which exhibits its own characteristic distribution within cytoarchitecturally distinct BST subnuclei. Corticotropin releasing factor (CRF)-, neurotensin (NT)-, somatostatin (SS)-, and enkephalin (ENK)-like immunoreactive (ir) neurons are particularly numerous within areas of the BST that project to the PB. In this study, we use the combined retrograde fluorescence-immunofluorescence method to determine whether neurons in the BST that project to the PB contain these immunoreactivities. After Fast Blue injections into PB, retrogradely labeled neurons were numerous throughout the lateral part of the BST, particularly in the dorsal lateral (DL) and posterior lateral subnuclei. Retrogradely labeled neurons were also present in the preoptic, ventral lateral, and supracapsular BST subnuclei and in the parastrial nucleus. Many of the CRF-ir, NT-ir, and SS-ir neurons in DL were retrogradely labeled. A few double-labeled cells of each type were also found in the posterior lateral, ventral lateral and supracapsular BST subnuclei ENK-ir neurons were never retrogradely labeled. Our results show that BST neurons that project to the PB stain for the same neuropeptides as those in the central nucleus of the amygdala (CeA) that project to the PB, demonstrating further the close anatomical relations between these two structures.

Brain natriuretic peptides: differential localization of a new family of neuropeptides.

Brain natriuretic peptide (BNP) is a recently discovered neuropeptide, isolated from the porcine brain, that is highly homologous to atriopeptin (AP), the atrial natriuretic peptide. We used a set of highly selective antisera against the two peptides to map their differential distribution immunohistochemically in the rat central nervous system. BNP immunoreactivity has a distinct distribution, involving many central autonomic and endocrine control structures that contain little if any AP immunoreactivity. AP and BNP belong to a family of neuropeptides that may be important in central cardiovascular control.

Lateral hypothalamic dynorphinergic efferents to the amygdala and brainstem in the rat.

Dynorphin is present within perikarya of the lateral hypothalamus (LH) and perifornical nucleus (PeF), and within nerve terminals of the central nucleus of the amygdala, central grey, parabrachial nucleus, and the dorsal vagal complex (nucleus of the solitary tract and dorsal motor nucleus of the vagus). Each of these nuclei receive efferent projections from the LH and PeF. In this study, the possibility that dynorphin cells with LH and PeF innervate each of these nuclei was investigated using a combined retrograde tracing-immunofluorescence technique. As enkephalinergic perikarya have also been localized to LH and PeF, peptide E (an enkephalin precursor fragment) was also studied for comparison. Following injections of fast blue into the central nucleus, parabrachial nucleus, central grey, and dorsal vagal complex, numerous retrogradely-labeled dynorphin-immunoreactive neurons were present within the LH and PeF. In comparison, retrogradely-labeled peptide E-immunoreactive cells were infrequently observed. These results suggest the LH and PeF to be a major source of dynorphin to the forebrain and brainstem.

Evidence for corticotropin-releasing factor, neurotensin, and somatostatin in the neural pathway from the central nucleus of the amygdala to the parabrachial nucleus.

The central nucleus of the amygdala (CNA) and the parabrachial nucleus of the pons (PBN) are included within a group of brain nuclei involved in autonomic responses. Previous studies have shown that the CNA sends a considerable projection to the PBN and that both nuclei contain neurons immunoreactive to many different peptides. In the present study, we used the combined retrograde fluorescence-immunofluorescence method to determine whether the CNA projection to the PBN contains any of the following neuropeptides: corticotropin-releasing factor (CRF), neurotensin (NT), somatostatin (SS), and enkephalin (ENK). Following injections of fluorescent dye into the PBN, neurons within both lateral and medial subdivisions of the CNA were retrogradely labeled. A significant percentage of CRF (54-66%)-, NT (40-53%)-, and SS (31-50%)-immunoreactive neurons were retrogradely labeled, predominantly within the lateral CNA. Enkephalin-immunoreactive neurons were never retrogradely labeled, although they were often found adjacent to retrogradely labeled neurons. Our results show that the lateral CNA is a major source of CRF, NT, and SS terminals within the PBN. Neurons in the medial CNA also provide a significant contribution to the CNA-PBN pathway, but their chemical nature remains to be determined. We conclude that CRF, NT, and SS are important putative neurotransmitters in the CNA's regulation of PBN function. This CNA-PBN peptidergic pathway may participate in stress-related cardiovascular and respiratory responses.

Peptidergic efferents from the intercalated nuclei of the amygdala to the parabrachial nucleus in the rat.

The peptide content of the intercalated nuclei (ICN) of the amygdala and their projection to the parabrachial nucleus was studied in the rat using the combined retrograde transport-immunofluorescence method. Neurotensin, and to a lesser extent, corticotropin-releasing factor and somatostatin, were found within ICN neurons which innervate the parabrachial nucleus. Enkephalin and somatostatin terminals were particularly dense around ICN neurons that project to the parabrachial nucleus. Our results indicate a functional link between the ICN and the lateral subdivision of the central nucleus of the amygdala based on their similar peptidergic projections to the parabrachial nucleus.