The origin,structure and occurrence of corpora amylacea in the bovine mammary gland and in milk

Summary Fibres growing from neurons of explanted dorsal root ganglia from 10 day chick embryos were transected and subsequently observed by light and electron microscopy after periods of a few to fifty minutes. Changes immediately proximal and distal to the cut together with alterations further away from the site of injury on both sides of the cut were recorded. Observations were also made on the growth cones of damaged axons and on changes in associated glial cells.Reactive and degenerative changes including the rotation, retraction and swelling of cut axons occurred rapidly. Electron microscopy revealed tracts of filamentous material close to the sealed-off ends of axons, swollen organelles such as mitochondria, and lamellar bodies of varying dimensions.Proximal to the injury and closer to the expiant, damaged and degenerating axons mingled with normal processes. Many contained only a fine granular material, others clumps of organelles, particularly mitochondria.Distal to the cut, microspikes were lost from some growth cones. The dense granular material filling microspikes and growth cones remained unchanged. Clumps of large clear vesicles, lamellar bodies and swollen degenerating mitochondria were present, not only within growth cones, but also in all parts of the axon distal to the cut.Glial cells associated with transected axons soon developed an electron dense cytoplasm containing swollen organelles. Large numbers of vesicles filled with a particulate substance were also found.The possible significance of the changes observed after transection are considered and discussed.The author wishes to thank Prof. D.W. James in whose laboratory at University College London these studies were initiated, Dr. A.R. Lieberman for his expert help and advice and the University of London Central Research Fund and Wellcome Trust for financial assistance     

Distribution of intrinsic nerve cell bodies and axons which take up aromatic amines and their precursors in the small intestine of the guinea-pig

Summary The sites of uptake, decarboxylation and retention of 1-dopa and the uptake and retention of dopamine and 6-hydroxytryptamine in the small intestine of the guinea-pig have been localised histochemically with a fluorescence technique for arylethylamines. In segments of ileum from untreated guinea-pigs only noradrenergic axons are fluorescent; these axons were eliminated by surgical denervation (crushing nerves running to the intestine through the mesentery) or by chemical denervation with 6-hydroxydopamine. In denervated segments of ileum, cell bodies and processes of intrinsic neurons become fluorescent after the injection of 1-dopa, dopamine or 6-hydroxytryptamine and the inhibition of monoamine oxidase, as do cells of Brunner's glands and Paneth cells. About 11% of the nerve cell bodies in the submucous plexus and 0.4% of those in the myenteric plexus become fluorescent. Varicose intrinsic axons which take up amines are found amongst the nerve cell bodies of the myenteric and submucous plexuses. They also ramify in the principal connections of the plexuses, in the tertiary strands of the myenteric plexus, in the deep muscular plexus and contribute sparse supplies of axons to arterioles in the submucosa and to the lamina propria of the mucosa. The axons are resistant to the degenerative actions of 6-hydroxydopamine.It is suggested that the intrinsic amine handling axons are more likely to utilise an indolamine related to 5-hydroxytryptamine than they are to utilise a catecholamine as a neurotransmitter.     

CHANGES IN CENTRAL NORADRENALINE NEURONSADMINISTRATION AFTER SYSTEMIC 6-HYDROXYDOPAMINE ADMINISTRATION

—Intravenous injection of a large dose of 6-hydroxydopamine (100 mg/kg) to adult rats caused a significant and long-lasting reduction (about 30 per cent) of the in oirro uptake of [³H]NA in the cerebral cortex and spinal cord, while no changes were seen in the hypothalamus. The endogenous NA in whole brain was similarly reduced (about 20 per cent). Fluorescence histochemistry revealed catecholamine accumulations which are degenerative signs, induced by 6-hydroxydopamine, in axons of the dorsal NA bundle innervating the cerebral cortex. It is concluded that the blood–brain barrier in adult rats is not completely protective with respect to the neurotoxic action of systemically injected 6-hydroxydopamine, which can produce degeneration of a significant number of NA nerve terminals in the cerebral cortex and spinal cord. Previous studies have shown that 6-hydroxydopamine caused a permanent and selective degeneration of a large number of central NA nerve terminals when injected systemically up to 1 week after birth, due to an incompletely developed blood-brain barrier. This barrier for 6-hydroxydopamine develops between the 7th and 9th day after birth (Sachs , 1973). In the present study 6-hydroxydopamine was found to cause a small transient reduction in [³H]NA uptake in cerebral cortex of rats between 9 and 28 days of age, while in older rats the damage produced by 6-hydroxydopamine was long-lasting. Thus, the NA nerves ascending to the cerebral cortex seem to possess a regenerative capacity to a 6-hydroxydopamine-induced degeneration up to about 28 days postnatally, but which later disappears or is markedly retarded.     

Innervation of the intestine in the bivalve mollusc Chione stutchburyi

Summary The innervation of the gut of the venerid bivalve mollusc, Chione stutchburyi, has been examined by fluorescence histochemistry, electron microscopy and autoradiography. Specific green and yellow varicose fluorescent fibres indicate the presence of dopaminergic and serotonergic axons, respectively. Three different types of axons can be distinguished by the morphological characteristics of their vesicles. Type I axons contain predominantly small granular vesicles (average diameter 65 nm), Type II axons possess large granular vesicles (average diameter 100 nm) and Type III axons contain large opaque vesicles (average diameter 150 nm). The granular vesicles in both Types I and II axons react positively to dichromate, and their granularity is reduced by reserpine indicating that they are monoaminergic. Only Type I axons accumulate tritiated dopamine and are selectively damaged by 6-hydroxydopamine. It is concluded that Type I axons are dopaminergic. Type II axons are serotonergic: they alone take up tritiated 5-hydroxytryptamine, and 5,7-dihydroxytryptamine selectively causes degenerative changes in these axons. Type III axons contain an unidentified neurotransmitter substance. The large opaque vesicles of these axons do not react to dichromate and are unaffected by reserpine, 6-hydroxydopamine or 5,7-dihydroxytryptamine.     

Calcium and inositol trisphosphate receptors

Work from the authors' laboratory is supported by the Wellcome Trust, and the Medical, and Agricultural and Food Research Councils. CWT is a Lister Institute Research Fellow.     

Histochemical properties of axons associated with the salivary apparatus of the cockroach, Nauphoeta cinerea

A variety of techniques have indicated that dopamine is probably the neurotransmitter at the salivary gland of the cockroach, Nauphoeta cinerea (Olivier). It is known from a previous ultrastructural study that two types of axon are associated with the gland but it is not known which of these axons contain catecholamines. The present study, using permanganate fixation or incubation in 5-hydroxydopamine or 6-hydroxydopamine, shows that only one category of axon contains catecholamines.     

Peripheral and central mechanisms of the pressor response elicited by stimulation of the locus coeruleus in the rat

Electrical stimulation of the pontine nucleus locus coeruleus (LC) caused an increase of the arterial blood pressure in anesthetized rats, and elevated plasma noradrenaline (NA) and adrenaline (A) levels. The stimulation-induced pressor response was characteristically biphasic and consisted of a sharp rise in arterial pressure at the onset of the stimulation, followed by a second elevation at the end of the stimulus. Bilateral adrenalectomy or adrenal demedullation completely blocked the secondary phase of the pressor response elicited by stimulation, but did not affect the primary phase. The latter was specifically eliminated by the destruction of the peripheral sympathetic vasomotor axons with intravenous 6-hydroxydopamine (6-OHDA). The active sites eliciting the secondary adrenomedullary pressor component appeared to be restricted to the nucleus LC, whereas the primary sympathetic vasomotor response could be elicited from sites in and around the nucleus. After brain transection at the midbrain level, stimulation of LC failed to evoke the adrenomedullary pressor response, while the sympathetic vasomotor component was not affected. Similarly, destruction of brain NA neurons by intraventricular administration of 6-OHDA did not change the sympathetic vasomotor response, but virtually abolished the adrenal response. The results demonstrate that the pressor response to stimulation of LC in the rat is due to both increased sympathetic vasomotor activity and CA released from the adrenal medulla. The study also provides evidence suggesting that the noradrenergic LC cell group play an important role in the activation of the adrenal medulla, but is not essential for the activation of the sympathetic vasoconstrictor fiber system.     

Trypanosoma (Schizotrypanum) dionisii breve n. subsp. from Chiroptera

Summary Study of deoxyribonucleic acid buoyant densities, enzymic electrophoretic mobilities and morphology in vitro of two stocks of Trypanosoma (Schizotrypanum) species from Myotis blythii oxygnathus (Chiroptera) in southern France led to the identification of T. (S.) dionisii breve n. subsp. It was differentiated from the nominate subspecies by the relative shortness of the long trypomastigotes developing in vitro (mean length 16.6±0.21 m, compared with 19–21 m), the presence of a smaller proportion of the deoxyribonucleic acid as satellite C, and different isoenzyme electrophoretic mobilities.This work was supported by the Medical Research Council and the Wellcome Trust.This work was supported by the Medical Research Council and the Wellcome Trust.     

Effects of intraventricular and intra-aquaductal 6-hydroxydopamine on monoamine containing neurons of the fowl paleostriatum, diencephalon and mesencephalon

The effects of a single intraventricular or intra-aquaductal infusion of 6-hydroxydopamine (6-OHDA) on monoamine fluorescence in the paleostriatum augmentatum, diencephalon and mesencephalon were studied. Present experiments have enable us to better characterize the distribution of catecholaminegic axons in the paleostriatum augmentatum, preoptic area, hypothalamus, median eminence, periventricular areas as well as of cell-bodies and axons exbiting green fluorescence in the n. mesencephalicus properties and other mesencephalic nuclei.     

Immunochemical evidence for the transport of neurophysin in the hypothalamo-neurohypophysial system of the dog

Summary 1. An immunohistochemical study has been made of the hypothalamo-neurohypophyseal system of the dog, 20h after crushing the pituitary stalk.2. By use of a cross-species-reactive neurophysin antiserum it was shown that neurophysin is a component of the axons which originate in the supraoptic and paraventricular nuclei and terminate around blood vessels in the posterior pituitary.3. Neurophysin specific fluorescence accumulated in axons proximal to the constriction but was absent from the axons immediately distal to the site of injury.4. In dogs left for six days it was shown by radioimmunoassay that the amount of neurophysin in the hypothalamus and stalk proximal to the constriction increased twofold while that remaining in the posterior pituitary and stalk distal to the constriction decreased five-fold over the same period.5. The results are interpreted as evidence for a rapid axonal transport of neurophysin from its site of synthesis in the cell bodies of the hypothalamus to the posterior pituitary. Acknowledgements: This work was supported by a research grant to D. B. Hope from the Medical Research Council. L. O. Uttenthal was supported by a Medical Research Training Award and B. G. Livett by a Nuffield Dominions Trust Demonstratorship (Australia). We thank Mrs. Marion Martin for radioimmunoassay of neurophysin, Miss Wendy Jones for technical assistance and the U.C.L.A. Brain Information Service for help with the bibliography.     

A light and electron microscope study of changes occurring at the cut ends following section of the dorsal roots of rat spinal nerves

Summary Rat dorsal spinal nerve roots were cut; 20 h later the axons in the vicinity of the cut were examined by light and electron microscopy. The changes in the cut tip distant from the ganglion were largely degenerative. On the ganglionic side of the cut a cap of free unmyelinated sprouts was formed. These sprouts contained clear and dense-core vesicles 40–150 nm in diameter, smooth endoplasmic reticulum and mitochondria. Some of the unmyelinated sprouts were extensions of myelinated axons, others arose from myelinated axons by lateral budding. In both myelinated and non-myelinated axons there was an accumulation of mitochondria, tubulo-vesicular smooth endoplasmic reticulum and large and small dense-core vesicles for a distance of approximately 500 m behind the tip. Dense-core vesicles were more common in nonmyelinated axons than in their myelinated counterparts. In areas of intense accumulation the non-myelinated fibres were grossly swollen and distorted. The myelinated axons and some of the sprouts contained an unusual type of mitochondrion. The similarity between these sprouts and pre-synaptic terminals is discussed.I.R.D. is supported by the Medical Research Council; P.K. thanks the Mental Health Trust for a project grant     

NORADRENALINE NERVE TERMINALS IN THE CEREBRAL CORTEX: EFFECTS ON NORADRENALINE UPTAKE AND STORAGE FOLLOWING AXONAL LESION WITH 6-HYDROXYDOPAMINE

The ascending noradrenaline-containing neuronal system from the locus coeruleus to the cerebral cortex was unilaterally lesioned by an intracerebral injection of 8 μg 6-hydroxydopamine in the dorsomedial reticular formation in the caudal mesencephalon. The 6-hydroxydopamine caused injury to axons of the dorsal catecholamine bundle associated with its specific neurotoxic action, while very limited unspecific tissue necrosis was observed. Following this treatment the endogenous noradrenaline in the ipsilateral cerebral cortex (neocortex) increased acutely (up to 2 days), as observed both with noradrenaline assay and fluorescence histochemistry. The noradrenaline concentration then gradually decreased to 15 per cent of the contralateral side 15 days after the lesion. At this time interval and up to at least 90 days no fluorescent catecholamine nerve terminals could be detected. The acute noradrenaline increase could be blocked partially by tyrosine hydroxylase inhibition produced by α-methyl-p-tyrosine. The disappearance of endogenous noradrenaline following tyrosine hydroxylase inhibition was also reduced after the 6-hydroxydopamine lesion. Studies on the in vitro uptake of [³H]noradrenaline (0.1 μM for 5 min) in slices from the neocortex after the 6-hydroxydopamine lesion showed a gradual decline in uptake reaching maximal reduction (35-40 per cent of the contralateral side) after 15 days. No recovery of [³H]noradrenaline uptake was seen up to 90 days after the lesion. The formation of [³H]noradrenaline from [³H]dopamine in vitro was reduced to 15 per cent of the contralateral side after a chronic lesion. The present results indicate that the disappearance of noradrenaline uptake-storage mechanisms in the neocortex is due to an anterograde degeneration of axons and nerve terminals of the dorsal catecholamine bundle. The data on endogenous noradrenaline and noradrenaline synthesis suggest that approx. 15 per cent of the noradrenaline nerve terminals in the neocortex remain intact following the lesion, while the [³H]noradrenaline uptake data reflect uptake in other tissue structures in addition to noradrenaline nerve terminals, e.g. dopamine nerve terminals, pericytes and/or glial cells.     

A genome-wide homozygosity association study identifies runs of homozygosity associated with rheumatoid arthritis in the human major histocompatibility complex

Rheumatoid arthritis (RA) is a chronic inflammatory disorder with a polygenic mode of inheritance. This study examined the hypothesis that runs of homozygosity (ROHs) play a recessive-acting role in the underlying RA genetic mechanism and identified RA-associated ROHs. Ours is the first genome-wide homozygosity association study for RA and characterized the ROH patterns associated with RA in the genomes of 2,000 RA patients and 3,000 normal controls of the Wellcome Trust Case Control Consortium. Genome scans consistently pinpointed two regions within the human major histocompatibility complex region containing RA-associated ROHs. The first region is from 32,451,664 bp to 32,846,093 bp (-log10(p)>22.6591). RA-susceptibility genes, such as HLA-DRB1, are contained in this region. The second region ranges from 32,933,485 bp to 33,585,118 bp (-log10(p)>8.3644) and contains other HLA-DPA1 and HLA-DPB1 genes. These two regions are physically close but are located in different blocks of linkage disequilibrium, and ～40% of the RA patients' genomes carry these ROHs in the two regions. By analyzing homozygote intensities, an ROH that is anchored by the single nucleotide polymorphism rs2027852 and flanked by HLA-DRB6 and HLA-DRB1 was found associated with increased risk for RA. The presence of this risky ROH provides a 62% accuracy to predict RA disease status. An independent genomic dataset from 868 RA patients and 1,194 control subjects of the North American Rheumatoid Arthritis Consortium successfully validated the results obtained using the Wellcome Trust Case Control Consortium data. In conclusion, this genome-wide homozygosity association study provides an alternative to allelic association mapping for the identification of recessive variants responsible for RA. The identified RA-associated ROHs uncover recessive components and missing heritability associated with RA and other autoimmune diseases.     

The effect of intraventricular 6-hydroxydopamine on the content of oxytocin and vasopressin in the hypothalamus and pituitary gland of water-deprived rats

The effect of intraventricular 6-hydroxydopamine on the content of oxytocin and vasopressin in the hypothalamus and pituitary gland of water deprived rats. Acta Physiol. Pol., 1977, 28 (6): 497-504. Rats received one infusion of 200 microgram 6-hydroxydopamine with 25 microgram of ascorbic acid into the lateral cerebral ventricle. After 57 days some rats were deprived of water for 4, 8 or 12 days. Then, the animals were sacrificed by decapitation. Oxytocin was determined in extracts from the posterior pituitary lobe and hypothalamus by the method of Van Dongen and Hays, while the vasopressin content was determined by the method of Dekanski. It was found that 6-hydroxydopamine injection into the cerebral ventricles causes a rise in oxytocin content in the hypothalamus and prevents its fall during--4--12 days of dehydration.     

The demonstration of cells bearing Fc receptors in the metrial gland of the pregnant rat uterus

Summary Cells obtained by collagenase treatment of metrial gland tissue from rats of day 12, 13, 14 and 15 of pregnancy were examined for the presence of surface membrane receptors for immunoglobulin (Fc receptors). Using an EA rosetting technique in which sheep red blood cells (SRBC) were sensitized with a rabbit anti-SRBC immunoglobulin preparation, Fc receptors were found on a proportion of the cells. The majority of the granulated metrial gland cells were not included in the rosetting cell population, suggesting that they do not possess the type of Fc receptor detected by this method. A comparison was made between results obtained when cells were counted in suspension and those obtained from cell counts on sections of fixed material. Both methods were found to yield similar results. Acknowledgements. Our thanks are due to Dr. A.E. Wild for his generous help, both in advice and in provision of immunoglobulins and immunoglobulin fractions, to Professor D. Bulmer and Dr. S. Peel for their continued help and advice, and to the Wellcome Trust for financial support.     

DOPAMINE-CONTAINING VASOMOTOR NERVES IN THE DOG KIDNEY

Abstract— The dopamine (DA) content of the canine renal cortex is greater than can be attributed to its presence in noradrenergic axons only. Most of the excess DA is in the outer part of the cortex. By fluorescence histochemistry numerous catecholamine-containing axons are seen to be associated with renal cortical arteries and arterioles. The fluorescence is abolished following treatment of animals with 6-hydroxydopamine or with reserpine, but is restored to some axons if reserpine is followed by systemic administration of 1-DOPA. This procedure does not restore fluorescence to atrial noradrenergic axons after reserpine-induced depletion. Pretreatment of animals with guanethidine abolishes axonal fluorescence and depletes tissue NA and DA from atrium, but in renal cortex the tissue DA level is little affected and some fluorescent axons remain. These results are discussed in the light of previous functional evidence for dopaminergic autonomic axons in the canine kidney.     

Distribution,pathways and reactions to drug treatment of nerves with neuropeptide Y- and pancreatic polypeptide-like immunoreactivity in the guinea-pig digestive tract

Pancreatic polypeptide-like immunoreactivity (PPLI) has been localized in nerves of the guinea-pig stomach and intestine with the use of antibodies raised against avian, bovine and human pancreatic polypeptide (PP), the C-terminal hexapeptide of mammalian PP, and against the related peptide, NPY. Each of the antibodies revealed the same population of neurones. Reactive cell bodies were found in both myenteric (5% of all neurones) and submucous ganglia (26% of all neurones) of the small intestine, and varicose processes were observed in the myenteric plexus, circular muscle, mucosa and around arterioles. The nerves were unaffected by bilateral subdiaphragmatic truncal vagotomy, but the staining of the periarterial nerves disappeared after treatment of animals with reserpine or 6-hydroxydopamine and was also absent after mesenteric nerves had been cut and allowed to degenerate. Vascular nerves showing immunoreactivity for dopamine beta-hydroxylase and PPLI had the same distribution. It is concluded that PPLI is located in periarterial noradrenergic nerves. However, other noradrenergic nerves in the intestine do not show PPLI, and PPLI also occurs in nerves that are not noradrenergic. Analysis of changes in the distribution of terminals after microsurgical lesions of pathways in the small intestine showed that processes of myenteric PP-nerve cells provide terminals in the underlying circular muscle and in myenteric ganglia up to about 2 mm more anal. Submucous PP-cell bodies provide terminals to the mucosa.     

Presynaptic Nicotinic Cholinergic Receptors Labeled by [3H]Acetylcholine on Catecholamine and Serotonin Axons in Brain

Nicotinic cholinergic receptor binding sites labeled by [3H]acetylcholine were measured in the cerebral cortices, thalami, striata, and hypothalami of rats lesioned by intraventricular injection of either 6-hydroxydopamine or 5, 7-dihydroxytryptamine. In addition, [3H]acetylcholine binding sites were measured in the cerebral cortices of rats lesioned by injection of ibotenic acid into the nucleus basalis magnocellularis. [3H]Acetylcholine binding was significantly decreased in the striata and hypothalami of both 6-hydroxydopamine- and 5,7-dihydroxytryptamine-lesioned rats. There was no change in binding in the cortex or thalamus by either lesion. Ibotenic acid lesions of the nucleus basalis magnocellularis, which projects cholinergic axons to the cortex, did not alter [3H]acetylcholine binding. These results provide evidence for a presynaptic location of nicotinic cholinergic binding sites on catecholamine and serotonin axons in the striatum and hypothalamus.     

GLIDE: GPU-Based Linear Regression for Detection of Epistasis

Due to recent advances in genotyping technologies, mapping phenotypes to single loci in the genome has become a standard technique in statistical genetics. However, one-locus mapping fails to explain much of the phenotypic variance in complex traits. Here, we present GLIDE, which maps phenotypes to pairs of genetic loci and systematically searches for the epistatic interactions expected to reveal part of this missing heritability. GLIDE makes use of the computational power of consumer-grade graphics cards to detect such interactions via linear regression. This enabled us to conduct a systematic two-locus mapping study on seven disease data sets from the Wellcome Trust Case Control Consortium and on in-house hippocampal volume data in 6 h per data set, while current single CPU-based approaches require more than a year's time to complete the same task.