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PubMed2006

Projections of the nucleus lentiformis mesencephali in pigeons (Columba livia): a comparison of the morphology and distribution of neurons with different efferent projections.

The avian nucleus lentiformis mesencephali (LM) is a visual structure involved in the optokinetic response. The LM consists of several morphologically distinct cell types. In the present study we sought to determine if different cell types had differential projections. Using retrograde tracers, we examined the morphology and distribution of LM neurons projecting to the vestibulocerebellum (VbC), inferior olive (IO), dorsal thalamus, nucleus of the basal optic root (nBOR), and midline mesencephalon. From injections into the latter two structures, small LM cells were labeled. More were localized to the lateral LM as opposed to medial LM. From injections into the dorsal thalamus, small neurons were found throughout LM. From injections into the VbC, large multipolar cells were found throughout LM. From injections into IO, a strip of medium-sized fusiform neurons along the border of the medial and lateral subnuclei was labeled. To investigate if neurons project to multiple targets we used fluorescent retrograde tracers. After injections into IO and VbC, double-labeled neurons were not observed in LM. Likewise, after injections into nBOR and IO, double-labeled neurons were not observed. Finally, we processed sections through LM for glutamic acid decarboxylase (GAD). Small neurons, mostly in the lateral LM, were labeled, suggesting that projections from LM to nBOR and midline mesencephalon are GABAergic. We conclude that two efferents of LM, VbC and IO, receive input from morphologically distinct neurons: large multipolar and medium-sized fusiform neurons, respectively. The dorsal thalamus, nBOR, and midline mesencephalon receive input from small neurons, some of which are likely GABAergic.

Animals↗

PubMed1986

Origin and central projections of rat dorsal penile nerve: possible direct projection to autonomic and somatic neurons by primary afferents of nonmuscle origin.

Cell number, size, and somatotopic arrangement within the spinal ganglia of the cells of origin of the rat dorsal penile nerve (DPN), and their spinal cord projections, were studied by loading the proximal stump of the severed DPN with horseradish peroxidase (HRP). The DPN sensory cells were located entirely in the sixth lumbar (L6) dorsal root ganglia (DRG), in which a mean of 468 +/- 78 cells per side were observed, measuring 26.7 +/- 0.8 microns in their longest axis (range 10-65 microns) and distributed apparently randomly within the ganglia. Within the spinal cord, no retrograde label was found, i.e., no motoneurons were labeled, indicating that in the rat the DPN is formed exclusively of sensory nerve fibers. Although labeled fibers entered the cord only through L6, transganglionically transported HRP was evident in all spinal segments examined, i.e., T13-S2. Labeled fibers projected along the inner edge of the dorsal horn (medial pathway) throughout their extensive craniosacral distribution. However, laminar distribution varied with spinal segment. In the dorsal horn, terminals or preterminal axons were found in the dorsal horn marginal zone (lamina I), the substantia gelatinosa (lamina II), the nucleus proprius (laminae III and IV--the most consistent projection), Clarke's column (lamina VI), and the dorsal gray commissure. In the ventral horn, terminals were found in lamina VII and lamina IX. Label apposed to cell somas and dendrites in lamina VII may represent direct primary afferent projections onto sympathetic autonomic neurons. In lamina IX, labeled terminals delineated the somas and dendrites of cells that appeared to be motoneurons. This is the first description of an apparently monosynaptic contact onto motoneurons by a primary afferent of nonmuscle origin.

Animals↗

PubMed1995

The efferent projections of the periaqueductal gray in the rat: a Phaseolus vulgaris-leucoagglutinin study. II. Descending projections.

The descending projections of the periaqueductal gray (PAG) have been studied in the rat using the anterograde tracer Phaseolus vulgaris-leucoagglutinin. The tracer was injected into the dorsolateral or ventrolateral subdivisions of the PAG at rostral or caudal sites. It was found that the patterns of the descending projections of the rostral and caudal parts of the dorsolateral PAG were the same and that the patterns of the descending projections of the rostral and caudal parts of the ventrolateral PAG were the same. However, the patterns of projections of the dorsolateral and ventrolateral PAG subregions were substantially different. These results suggest that the dorsolateral and ventrolateral parts of the PAG are organized into longitudinal columns that extend throughout the length of the PAG. The axons of PAG neurons descended through the pons and medulla via two routes. A small fiber bundle was present in the periaqueductal gray and in the periventricular area. This bundle distributed fibers and terminals locally within the periaqueductal gray and in the locus coeruleus and Barrington's nucleus. A larger bundle had a diffuse arrangement in the pontine reticular formation, however, and it had a more restricted distribution in the medulla, where it occupied a position dorsolateral to the pyramid. This bundle supplied structures in the pontine and medullary tegmentum. The dorsolateral column preferentially supplied the locus coeruleus, subcoeruleus, the gigantocellular nucleus pars alpha, the rostral part of the paragigantocellular nucleus, and the region of the A5 noradrenergic cell group. The ventrolateral column preferentially supplied the nucleus raphe magnus, the caudal part of the lateral paragigantocellular nucleus, and the rostroventrolateral reticular nucleus.

Animals↗

PubMed1981

Distribution and specific central projections of mechanoreceptors in the thorax and proximal leg joints of locusts. I. Morphology, location and innervation of internal proprioceptors of pro- and metathorax and their central projections.

The mechanoreceptive supply of ventral thoracic parts and proximal leg joints of the pro- and metathorax of two locust species has been studied with the help of a modification of the axonal infusion technique with cobaltous chloride, which permits staining of the peripheral nervous system of an entire segment. The number, location, and innervation of serially homologous chordotonal organs (CO), strand receptors (SR), multipolar sensilla (MS), hair plates (HP) and clustered campaniform sensilla (CS) are described, as well as population specific central projections of primary afferent fibers from internal receptors (CO, MS). CO projections tend to form intersegmental projections within the thoracic ganglia, the extent varying with the organ's location. Apart from dorso-lateral collaterals, they terminate mainly in the medioventral neuropile, where they also cross the longitudinal midline of the CNS. By contrast, MS projections stay ipsilateral and do not leave their ganglia, where they send collaterals into all levels of the neuropile.

Animals↗

PubMed1985

Spinal projections of the gigantocellular reticular formation in the rat. Evidence for projections from different areas to laminae I and II and lamina IX.

We have used the autoradiographic method to study the organization of spinal projections from the gigantocellular reticular nucleus in the rat. Of particular note was the evidence obtained for projections to laminae I, II and IX. Reticular projections to laminae I and II arise more rostrally in Gi than those to lamina IX. Projections to laminae III-VIII and X as well as to autonomic nuclei have also been documented. Our results suggest that the gigantocellular reticular nucleus of the rat can be subdivided on connectional grounds.

Animals↗

PubMed1987

The cerebellar corticonuclear projection from lobule Vb/c of the cat anterior lobe: a combined electrophysiological and autoradiographic study. II. Projections from the vermis.

The present study is an investigation of the efferent pathways from Purkinje cells within particular sagittal zones of the vermal region of the cat cerebellar cortex. A combined electrophysiological/autoradiographic technique was used, in which a small volume (10-120 nl) of 3H-leucine was injected into the centre of a chosen cortical zone after the mediolateral extent of the zone had been delimited electrophysiologically on the basis of its climbing fibre input. Study of the uptake and orthograde transport of labelled material by the Purkinje cells showed that the smallest injections gave rise to injection sites which were restricted to a single zone and to terminal labelling which was very reproducible between cases. Larger injections usually resulted in spread of labelled material to neighbouring zones but the resultant distribution of terminal labelling was nevertheless consistent with that arising from smaller injections. The x zone, which receives climbing fibre input transmitted from the ipsilateral forelimb via a dorsal funiculus spino-olivo-cerebellar pathway (DF-SOCP), was found to project to the junctional region between nucleus fastigius and nucleus interpositus posterior (NIP). The b zone, which lies laterally in the vermis and receives climbing fibre input transmitted from both forelimbs (and both hindlimbs) via a slower conducting SOCP, was found to project, not to the cerebellar nuclei proper, but to the ipsilateral lateral vestibular nucleus. The projection of the third zone within the vermis, the a zone, was not examined but it is generally agreed that this zone projects mainly to nucleus fastigius.

Animals↗

PubMed1988

Separate non-cholinergic descending projections and cholinergic ascending projections from the nucleus tegmenti pedunculopontinus.

A substantial population of cells from the nucleus tegmenti pedunculopontinus was demonstrated to have descending projections to the spinal cord using fluorescent retrograde axonal tracers. Double-labeling studies showed that separate perikarya in this region have descending versus ascending projections. The distributions of the cell bodies with ascending or descending projections were spatially distinct, but partially overlapping. Some ascending, but not the descending, projections were cholinergic.

Acetylcholine↗

PubMed1989

Corticonuclear and corticovestibular projections from the uvula in the albino rat: differential projections from sublobuli of the uvula.

The organization of the corticonuclear and corticovestibular projections from the uvula was investigated in the albino rat by an autoradiographic method. The corticonuclear fibers from sublobule a of the uvula terminated in the caudoventral part of the medial cerebellar nucleus, and the caudomedial part of the posterior interpositus nucleus with mediolateral topography. The medial and lateral portions of the sublobule projected to the medial cerebellar and posterior interpositus nuclei, respectively. The corticovestibular fibers from sublobule a terminated in the dorsal and rostral parts of the superior vestibular nucleus, the dorsal part of the lateral vestibular nucleus, and the caudomedial part of the spinal vestibular nucleus. However, the corticonuclear fibers from sublobuli b and c of the uvula terminated additionally in the ventromedial part of the lateral cerebellar nucleus, while the corticovestibular fibers from these sublobuli terminated additionally in the subnucleus y of the vestibular complex, with probable termination in the medial vestibular nucleus. The cortical region which sent efferent projections to the ventromedial part of the lateral cerebellar nucleus and the subnucleus y was located laterally in sublobuli b and c of the uvula. These differential projection patterns from the dorsal and ventral sublobuli suggest the difference of the functional correlates between the sublobuli in the uvula.

Animals↗

PubMed1990

Neurons in the sacral parasympathetic nucleus that project to the hypothalamus do not also project through the pelvic nerve--a double labeling study combining Fluoro-gold and cholera toxin B in the rat.

We recently reported that neurons in the sacral parasympathetic nucleus (SPN) project directly to the hypothalamus. In the present study, we examined the possibility that individual neurons in SPN send both an axon into the pelvic nerve and an ascending projection to the hypothalamus. We used a new double-labeling technique in which two sensitive retrograde tracers (Fluoro-gold and cholera toxin subunit B immunocytochemically stained with rhodamine-labeled antibodies) were combined. The effectiveness of this combination for singly and doubly labeling neurons was established in experiments in which both tracers were injected into overlapping areas of the tongue or ventrobasal thalamus. These injections doubly labeled large numbers of neurons in the hypoglossal or dorsal column nuclei, respectively. In studies of the projections of neurons in the SPN, injection of one tracer into the hypothalamus and the other into the pelvic nerve and/or pelvic ganglion singly labeled many neurons (more than 3300 in the 7 examined cases). However, no SPN neurons were doubly labeled. These findings indicate that the SPN in the rat consists of at least two distinct groups of cells, parasympathetic preganglionic neurons and neurons that project to the hypothalamus.

Animals↗

PubMed1996

Crossed projection neurons are generated prior to uncrossed projection neurons in the lateral superior olive of the rat.

The present study examined in the lateral superior olive (LSO) of the rat whether LSO neurons projecting to the ipsilateral inferior colliculus (IC) might be generated later than those projecting to the contralateral IC. Rat fetuses were exposed in utero to 5-bromodeoxyuridine (BrdU), a thymidine analogue, to label neurons proliferating at different embryonic stages from day E11 through to E20. Upon reaching adulthood, the rats were given unilateral injections of fluoro-gold (FG), a retrograde fluorescent tracer, into the IC. Subsequently, the tissue sections of the brains obtained from the rats were immunostained for BrdU to simultaneously detect neurons that were BrdU-positive and/or FG-positive. BrdU-positive LSO neurons were found in the rats which had been exposed to BrdU during E12-E16. In E12 and E13 BrdU-exposure cases, the vast majority of doubled-labeled (BrdU-positive and FG-positive) neurons were seen on the contralateral side to the FG injection. In E14, E15 and E16 BrdU-exposure cases, in contrast, all double-labeled neurons were found on the ipsilateral side to the FG injection. The distribution of these double-labeled neurons within the nucleus was diffuse in all the BrdU-exposure cases. Thus, the results indicate that LSO neurons are generated during E12-E16, that the crossed projection neurons are generated 1-4 days earlier than the uncrossed projection neurons, and that no topographical relationships exist between the early- and the late-generated populations of the LSO neurons.

Animals↗

PubMed1995

Olivary projecting neurons in the nucleus prepositus hypoglossi, group y and ventral dentate nucleus do not project to the oculomotor complex in the rabbit and the rat.

The nucleus prepositus hypoglossi, dorsal group y, ventral dentate nucleus, and medial vestibular nucleus all project to both the oculomotor complex and inferior olive. In the present study, we demonstrate with the use of retrograde double labeling techniques in rabbits and rats, that the neurons in these pre-oculomotor nuclei that project to the inferior olive are intermingled with those that project to the oculomotor nucleus, but that virtually none project to both.

Animals↗

PubMed2000

An anterograde and retrograde tract-tracing study on the projections from the thalamic gustatory area in the rat: distribution of neurons projecting to the insular cortex and amygdaloid complex.

Projections from the thalamic gustatory nucleus, i.e. the parvicellular part of the posteromedial ventral thalamic nucleus (VPMpc) to the forebrain regions were studied in the rat by the tract-tracing methods with anterograde tracer (biotinylated dextran amine, BDA) and anterograde/retrograde tracer (wheat-germ agglutinin-horseradish peroxidase, WGA-HRP). After BDA injection into the VPMpc, terminal labeling was observed in the insular cortex, amygdaloid complex, and fundus striati. The terminal labeling in the amygdaloid complex was distributed in dorsolateral area of the rostral part of the lateral amygdaloid nucleus and the rostral part of the lateral subdivision of the central amygdaloid nucleus. The terminal labeling in the central amygdaloid nucleus extended to the fundus striati. The retrograde tracing study with WGA-HRP revealed that the projection fibers from the VPMpc to the amygdaloid complex originated from the medial part of the VPMpc and also from the thalamic area medial to the VPMpc. In the rats injected with Fluoro-Gold and WGA-HRP, respectively into the insular cortex and amygdaloid complex, no double-labeled neuronal cell bodies were found in the VPMpc, although neurons labeled singly with Fluoro-Gold were intermingled with those singly labeled with WGA-HRP in the medial part of the VPMpc. The results indicated that VPMpc neurons projecting to the amygdaloid complex constituted a population different from VPMpc neurons projecting to the insular cortex.

Amygdala↗

PubMed1998

The family health project: a multidisciplinary longitudinal investigation of children whose mothers are HIV infected. Family Health Project Research Group.

This article introduces The Family Health Project, a multidisciplinary longitudinal investigation of children and their HIV-infected mothers and a comparison sample from the same inner-city environment. The background literature, purpose of the Project, advantages and challenges of interdisciplinary collaboration, methods of study including participant and design issues, overview of preliminary findings, clinical implications, and social policy implications are presented. Beyond introducing a new and important project examining a neglected sample in our society, the present article is intended to provide useful guidelines for other multidisciplinary large-scale clinical research projects.

Adolescent↗

PubMedDate not supplied

The EPIC project in Savona: an example of dissemination of an EU-AIM project at municipal level.

We present a local Dissemination of EPIC, a project which has been devised to support health and social primary care by an information system. One key point of the EPIC project was a standardization effort at European level, providing a standardized basis for the management system based on client needs for planning and manpower control. Whilst EPIC has been designed as a general community information system, the main EPIC applications focus is on the care of the elderly. Savona is a middle size Italian town with a high percentage of elderly people and has already had an experience of integration of health and social care within an Italian project. It has therefore been regarded as a suitable site for the dissemination of EPIC. The EPIC application solved some of the information problems which emerged during the validation of the previous Italian project, such as the definition of the requirements; the collection, processing and retrieval of the clinical/social data; the definition of responsibilities and relations of the operators.

Aged↗

PubMed1988

[The MONICA project. A WHO research project in cardiovascular diseases].

The MONICA Project is an international research program coordinated by WHO. It aims at studying the relationships of simultaneous temporal variations during a 10-year period a) of a morbidity index (acute myocardial infarction) and of the risk factors levels and b) of mortality indexes (lethality of acute infarction and coronary mortality) and of the medical care level. The study of the relationships will take into account the temporal variations measured in the numerous centers participating in the Project. It uses the methodology of registers completed by population studies and studies among patient cohorts. The whole methodology is standardized by a permanent quality control. A French participation (MONICA-France Project) includes 3 registers (Bas-Rhin, Haute-Garonne, Lille) with a national coordination and an autonomous analysis. The MONICA Project must provide public health information and should suggest hypotheses, but it must also be a "tool for research".

Adult↗

PubMed1995

Nurses' perceptions of involvement in Thunder Project. American Association of Critical-Care Nurses Thunder Project task force.

The American Association of Critical-Care Nurse's (AACN) Thunder Project was conceptualized and developed to provide critical-care nurses with a research protocol ready for institutional review and implementation. Project goals included providing a research package (protocol, educational, and data collection materials) and a topic of clinical significance to critical-care nurses. Site coordinators and research associates were identified at participating institutions to coordinate and implement all study activities. In this article, an evaluation study undertaken to recount perceptions of site coordinators and research associates in relation to project goals and research experience is described. Data demonstrated that study goals were achieved, and research experience was considered professionally enhancing. Written comments described barriers to project implementation at participating sites. Obtaining informed consent and physician approval and/or cooperation were identified as significant barriers to implementation at some sites.

Attitude of Health Personnel↗

PubMed2004

Projection, introjection, and projective identification: a reformulation.

In this essay, the author recommends a reformulation of the psychoanalytic concept of projection. The author proposes that projective processes are not merely defensive maneuvers that interfere with perception, but rather an essential means by which human perception is rendered possible. It is the manner in which human beings test and-evaluate reality in terms of their experiential structure, and their needs for survival and nourishment. Projection is the early phase of introjection.

Fantasy↗

PubMedDate not supplied

The Imo State (Nigeria) Drinking Water Supply and Sanitation Project, 1. Description of the project, evaluation methods, and impact on intervening variables.

A health impact evaluation was conducted in conjunction with the Imo State Drinking Water Supply and Sanitation Project in Nigeria. The project consisted of a package of water supply, sanitation, and health and hygiene education given by village-based workers. The evaluation was a quasi-experimental study covering pre-, peri- and post-intervention periods. Data were collected from 3 intervention and 2 control villages. Baseline surveys indicated that the intervention and control areas were similar with respect to most socio-demographic variables. Use of the improved water supply was high, although this was influenced by borehole-to-population ratios and household-to-borehole distances. Water collection time was consequently greatly reduced. Data from a small sample of households showed that borehole water became heavily contaminated during collection and storage, and that there was no significant change in consumption of water per person. Adults in 46% of household units in the intervention area were using ventilated improved pit latrines by the end of the study period. Use by young children (2-5 years old), however, was low. Limitations in the success of the health education component of the project were found. Although changes were found in knowledge, attitudes and practices related to water and sanitation, and in management of childhood diarrhoea, this occurred in both the intervention and control areas.

Health Education↗