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PubMed2003

Topographic organization of projections from the amygdala to the visual cortex in the macaque monkey.

The topography of amygdaloid projections to the visual cortices in the macaque monkey was examined by injecting the fluorescent tracers Fast Blue and Diamidino Yellow at different locations in the occipital and temporal lobes and mapping the distribution of retrogradely labeled cells in the amygdala. Injections involving regions from rostral area TE to caudal area V1 all resulted in labeled cells within the basal nucleus of the amygdala. Relatively few double-labeled cells were observed even when the two injections were separated by less than 3 mm. The projections were rostrocaudally organized such that projections to caudal visual areas originated from dorsal and caudal portions of the magnocellular division of the basal nucleus while projections to more rostrally situated visual areas originated in more rostral and ventral portions of the basal nucleus. When injections involved rostral and medial portions of area TE, retrogradely labeled cells were observed in the accessory basal and lateral nuclei in addition to the basal nucleus. These data confirm that the amygdala gives rise to feedback projections to all levels of the "ventral stream" visual pathway. The projections do not appear to be diffusely distributed since few double-labeled cells were observed. The largest cells of the basal nucleus, those located in the magnocellular division, project the farthest in the visual system and innervate all occipital and temporal levels. The smaller cells, in the intermediate and parvicellular regions, project to more rostral and medial portions of the visual cortex. These results suggest that the amygdala may have substantial modulatory control over sensory processing at all stages of the ventral-stream visual cortical hierarchy.

Amidines↗
PubMed1998

GABAergic and cholinergic basal forebrain and preoptic-anterior hypothalamic projections to the mediodorsal nucleus of the thalamus in the cat.

The present study examined projections of GABAergic and cholinergic neurons from the basal forebrain and preoptic-anterior hypothalamus to the "intermediate" part of the mediodorsal nucleus of the thalamus. Retrograde transport from this region of the mediodorsal nucleus was investigated using horseradish peroxidase-conjugated wheatgerm agglutinin in combination with peroxidase-antiperoxidase immunohistochemical staining for glutamic acid decarboxylase and choline acetyltransferase. A relatively large number of retrogradely-labelled glutamic acid decarboxylase-positive neurons are located in the basal forebrain, amounting to more than 7% of the total population of glutamic acid decarboxylase-positive cells in this region. Moreover, retrogradely-labelled choline acetyltransferase-positive cells are interspersed among glutamic acid decarboxylase-positive neurons, accounting for about 6% of the total choline acetyltransferase-positive cell population in the basal forebrain. The glutamic acid decarboxylase-positive and choline acetyltransferase-positive retrogradely-labelled neurons are distributed throughout several regions of the basal forebrain, including the medial septum, the diagonal band of Broca, the magnocellular preoptic nucleus, the substantia innominata pars anterior, the substantia innominata pars posterior, and the globus pallidus where only a few retrogradely-labelled neurons were seen. The choline acetyltransferase-positive mediodorsal-projecting neurons are morphologically different from the choline acetyltransferase-positive neurons in the basal forebrain, suggesting that those projecting to the mediodorsal nucleus are a small proportion of the cholinergic neuronal population in the basal forebrain. In the preoptic-anterior hypothalamus, many retrogradely-labelled glutamic acid decarboxylase-positive cells were found, amounting to more than 7% of the total population of glutamic acid decarboxylase-positive cells in this region. These retrogradely-labelled glutamic acid decarboxylase-positive neurons are distributed throughout the preoptic-anterior hypothalamus in a continuous line with those in the basal forebrain, including the lateral preoptic area, the medial preoptic area, the bed nucleus of the stria terminalis, and the anterior and dorsal hypothalamic areas. The highest percentage of mediodorsal-projecting GABAergic neurons is in the anterior lateral hypothalamus where more than 25% of the total population of glutamic acid decarboxylase-positive cells project to the mediodorsal nucleus of the thalamus. Overall, of the large population of retrogradely-labelled neurons in the basal forebrain and preoptic-anterior hypothalamus, a significant proportion are glutamic acid decarboxylase-positive neurons (> 60% in the basal forebrain and > 30% in the preoptic-anterior hypothalamus), while the choline acetyltransferase-positive neurons amount to a smaller percentage of the neurons projecting to the mediodorsal nucleus (< 13% in the basal forebrain and < 2% in the preoptic-anterior hypothalamus). These results provide anatomical evidence of direct GABAergic projections from the basal forebrain and preoptic-anterior hypothalamic regions to the "intermediate" part of the mediodorsal nucleus in the cat. This GABAergic projection field could be the direct pathway by which the basal forebrain directly modulates thalamic excitability and may also be involved in mechanisms modulating electroencephalographic synchronization and sleep through the "intermediate" mediodorsal nucleus.

Animals↗
PubMed1998

Trigeminal projections to thalamus and subthalamus in the hedgehog tenrec.

The objective of the present study was the identification and characterization of the trigemino-diencephalic target areas in the Madagascan lesser hedgehog tenrec in order to get a more comprehensive view on the mammalian somatosensory thalamus, its evolution and representation in different species. Such an analysis has been considered important because in lower mammals the head and face are relatively well represented, but their ascending trigeminal projections have scarcely been analysed. Following injections of different tracer substances into the rostral and caudal portions of the trigeminal nuclear complex the most prominent area of termination was found in the medial ventroposterior nucleus. These projections were patchy and scarcely overlapped the region previously shown to receive spinal and dorsal column nuclear afferents. On the basis of the laterality and the intensity of the projections, two subdivisions were distinguished, the principal portion and the accessory portion receiving a dense contralateral and a weak bilateral input, respectively. They were considered equivalents to the magnocellular and parvocellular subdivisions of the medial ventroposterior nucleus in more differentiated mammals. In the latter species, however, the overlap between trigeminal and parabrachial fibres appears less extensive than in the tenrec. In addition, a weak bilateral projection was shown from the caudal trigeminal nucleus to the caudal and dorsal subdivision of the nucleus submedius. There was little, if any evidence for a trigeminal projection to the intralaminar nuclei and we failed to identify a correlate to the posterior nuclear complex of higher mammals. On the other hand, there was a distinct contralateral projection to the ventral portion of the zona incerta. This projection was of similar strength as the projection to the medial ventroposterior nucleus; it supports the notion that the zona incerta may play a crucial role in relaying trigeminal information.

Animals↗
PubMed2000

A comparative analysis of the morphology of corticothalamic projections in mammals.

Recent anatomical tracing methods have revealed new principles underlying the organization of corticothalamic connections in the mammalian nervous system. These data demonstrated the distribution of two types of synaptic contacts in the corticothalamic projection: small (<1 microm) and giant (2-10 microm) axon terminals. We compare the organization of corticothalamic projections in the auditory, somatosensory, visual, and motor systems of a variety of mammalian species, including the monkey. In all these systems and species, both types of corticothalamic terminals have been observed. Small endings formed the major corticothalamic terminal field, whereas giant terminals were less numerous and formed additional terminal fields together with small terminals. After comparing their spatial distribution, as well as the degree of reciprocity between the corticothalamic and thalamocortical projections, different roles are proposed for small and giant endings. Small terminals are typically present in the projection serving the feed-back control of the cerebral cortex on the thalamic nucleus from which it receives its main projection. In contrast, giant terminals are involved in feed-forward projections by which activity from a cortical area is distributed, via the thalamus, to other parts of the cerebral cortex. The cross-species and cross-systems comparison reveals differences in the mode of feed-forward projection, which may be involved in the activation of other parts of the same cortical area or form part of a projection that activates other cortical areas.

Animals↗
PubMed1996

Projections from the ventral cochlear nucleus to the inferior colliculus and the contralateral cochlear nucleus in guinea pigs.

Multipolar cells in the ventral cochlear nucleus are the source of projections to numerous brainstem auditory nuclei, including the contralateral and ipsilateral inferior colliculi and the contralateral cochlear nucleus. Multiple fluorescent tracers were used to label the multipolar cells that project to each of these targets. Following injections of different tracers into each target, the ventral cochlear nucleus was examined for the presence of cells that contained more than one tracer. Such cells were never observed. In contrast, double-labeled cells were common in the dorsal cochlear nucleus, where cells frequently contained the two tracers that were injected into the ipsilateral and contralateral inferior colliculi. The distribution and somatic morphology of cells in the ventral cochlear nucleus that project to each of the three targets were examined. Each population contained cells with somas that ranged in shape from elongated to rounded, but there were differences in soma size. Projections to the ipsilateral and contralateral inferior colliculi arise predominantly from small to medium-sized cells, the average size being slightly less for cells with projections to the ipsilateral colliculus. Projections to the contralateral cochlear nucleus arise from cells with somas that range in size from small to large, including cells much larger than those that projected to either inferior colliculus. On the basis of these results, we conclude that projections from the ventral cochlear nucleus to the ipsilateral and contralateral inferior colliculi and to the contralateral cochlear nucleus arise in three different populations of multipolar cells.

Analysis of Variance↗
PubMed1986

The morphology and divergent axonal organization of midbrain raphe projection neurons in the rat.

The morphology of dorsal raphe neurons was examined using intracellular injections of horseradish peroxidase (HRP) and the Golgi technique. Light microscopic examination of HRP-labeled projection neurons revealed a neuron type with radiating, poorly branched and sparsely spined dendrites and terminal dendritic thickets. The stem axon of these neurons left the nucleus ventrally but gave off a beaded collateral while still within the parent cell's dendritic domain. Somatodendritic morphology from Golgi-Kopsch stained material coincided with intracellular HRP findings and the dorsal raphe may consist of varieties of one basic morphological type of neuron. Intracellular recordings made during the HRP injection experiments confirmed that stimulation of the ventral medial tegmentum elicited an antidromic action potential and an inhibitory postsynaptic potential in dorsal raphe projection neurons. The order of axonal projections arising from the midbrain raphe nuclei was examined using a double retrograde axonal tracing technique. After paired HRP and [3H] wheat germ agglutinin injections within certain projection targets of the dorsal and median raphe neurons (caudate-putamen, amygdala, hippocampus, substantia nigra and locus coeruleus), each target structure was found to have its own unique representation within a topographically distinct portion of one or more of the raphe subgroups. Neurons projecting to the caudate-putamen and substantia nigra occupied rather rostral portions. Neurons projecting to the hippocampus and locus coeruleus resided more caudally. Neurons projecting to the amygdala were situated intermediately. Overall, rostrocaudal topography in the intranuclear distributions of raphe projection neurons resulted in the formation of complex overlap zones where collateralized neurons always resided.

Action Potentials↗
PubMed2000

Implementing CQI projects in hospitals.

BACKGROUND: Quality improvement approaches such as continuous quality improvement (CQI) and total quality management are widely used, but little is known about how much it costs to use the principles and techniques required to implement CQI processes. In the Robert Wood Johnson Foundation's Improving the Quality of Hospital Care (IQHC) program, four consortia of hospitals were funded in the early 1990s. Interviews with quality managers at 38 of the consortia hospitals were conducted in 1995 to determine the costs of conducting CQI projects to allow an estimation of the marginal cost of using CQI processes (particularly cross-disciplinary teams) to improve quality of care. CQI PROJECTS: Quality managers described 69% of project outcomes as critical to clinical services. Team members identified the issues their teams addressed and selected the project 64% of the time, the methods of analysis 87% of the time, and the approaches to resolving the problem or issue 97% of the time. Most of the respondents agreed that the team members had the authority to resolve the problem without appealing to higher levels of management. Costs for hospitals' most recently completed projects varied widely, from $148 for the entire project to $18,590. The length or duration of the projects also varied widely, from 1 month to 66 months. DISCUSSION: In the hospitals included in this sample, all of which were highly self-selected (evidenced by their participation in a voluntary consortium of hospitals focused on quality of care), knowledge of CQI processes appeared to be fairly thorough. Teams appeared to have a reasonable amount of autonomy. New CQI projects should be subjected to scrutiny in terms of their likely contribution to quality of care, as distinct from other positive outcomes.

Hospital Administration↗
PubMed2001

A survey of 92 quality improvement projects.

BACKGROUND: Studies focusing on the impact of improvement efforts on the organization have yielded mixed results, which has increased interest in comparing the processes of improvement used. Data for a convenience sample of 92 quality improvement (QI) projects in 32 organizations were gathered from interviews and self-reported surveys from 1998 to 2000. A self-administered questionnaire was developed to measure 70 characteristics of improvement projects. RESULTS: Most (80%) of the improvement projects were conducted by hospitals or clinics affiliated with hospitals. The projects took an average of 13 months from the team's first meeting to the end of the pilot study. Project teams met 14 times (approximately once a month) and spent 1.5 hours per meeting. Some projects did not measure the impact, others did not intend to have a specific impact, and still others measured but did not achieve the planned impact. DISCUSSION: Patients and employees may be benefitting from improvement projects, but organizations may not be leveraging these improvements to reduce cost of delivery or increase market share. Considerable variation in the projects' impact raises the question of the need to improve the improvement methods. Generalization from this study should be made with caution, as data were based on a self-selected convenience sample of organizations. Furthermore, respondents did not complete all items, and missing information may affect the conclusions. The data on current improvement practices that are provided in this study can serve as baseline data against which rapid improvement efforts can be judged.

Health Care Surveys↗
PubMed2000

HIS purchase projects in public hospitals of Styria, Austria.

The Steiermärkische Krankenanstaltenges. m.b.H (KAGes) is a company, owned by the province of Styria in Austria, which operates 21 hospitals with about 8000 beds and 14000 employees, serving a population of ca. 1.2 million people. KAGes has purchased a new hospital information system (HIS) for its hospitals. Within the strategic IT plan and the 'system structure new' (SSN) project, a methodology was developed for making an effective HIS purchase. Several steps of this project are described in the paper, request for product information, evaluation of vendor proposals, product presentations, test site evaluation, reference site visits and selection of vendor finalists. The authors present the internal project management methodology, including the structure of the project team, project information management through intranet, criteria for different steps of the evaluation and evaluation site organization. Four major HIS vendors with leading HIS products qualified for this stage of the project (evaluation site). About 60 teams with 400 members (end users and IT-experts) have assessed all the products installed, during one or more, repeated test sessions. The decision on which new HIS to purchase were based on the recommendations derived from this evaluation. After completing SSN-project with the suggestion to KAGes-top-management for negotiations with two vendor finalists, the new project named MEDOCS was started mid-1999. Two pilot installations (one general hospital and one teaching hospital department) are nowadays in the pilot implementation and subsequent roll-out (including substitution of the legacy system) is scheduled until the year 2003.

Austria↗
PubMed1990

Preoccipital cortex receives a differential input from the frontal eye field and projects to the pretectal olivary nucleus and other visuomotor-related structures in the rhesus monkey.

The bidirectional axonal transport capabilities of the horseradish peroxidase (HRP) technique facilitated the study of the frontal-eye-field (FEF) input and pretectal output of two regions of extrastriate preoccipital cortex (POC). Following horseradish peroxidase (HRP) gel implants into the middle and dorsal POC in two rhesus monkeys, the middle POC implant demonstrated retrograde frontal cortical labeling largely restricted to the inferior frontal eye field (iFEF) and adjacent inferior prefrontal convexity, whereas the dorsal POC implant showed labeling in the caudal ventral bank of the superior ramus of the arcuate sulcus (sas) and middle-to-dorsal region of the rostral bank of the concavity of the arcuate sulcus (dorsal FEF). Prominent anterogradely labeled efferent preoccipital projections were observed to the ipsilateral pretectal olivary nucleus (PON) and to a lesser extent the anterior pretectal nucleus. Although the middle POC case had heavier projections to the lateral PON, the dorsal case projected more heavily to the medial PON. In addition, both implants demonstrated subcortical connections with the lateral and dorsal inferior pulvinar nuclei, central superior lateral thalamic intralaminar nucleus, caudate nucleus, and middle-to-ventral claustrum. However, while the middle POC implant had efferent projections to the superficial superior colliculus (SC), pregeniculate nucleus (PGN), lateral terminal accessory optic nucleus (LTN), and dorsolateral pontine nucleus (DLPN), resembling those previously reported for the middle temporal (MT) visual area (Maunsell & Van Essen, 1982; Ungerleider et al., 1984), the dorsal implant had projections to the lateral intermediate SC, zona incerta (ZI), PGN, a notably lesser projection to the LTN, and basilar pontine projections to the lateral and lateral dorsal pontine subnuclei (not including the extreme dorsolateral DLPN). These preliminary results suggest that the preoccipital cortex, which reportedly functions in pupillary constriction, accommodation, and convergence, entertains connections with the PON and other visuomotor-related structures, and thus could act as an intermediary in the pathway between the iFEF and PON, and provide a possible explanation for pupillary effects that occur with stimulation of the FEF (Jampel, 1960) and within the contex of other oculomotor activities. The findings shed light on certain differences in connections of middle vs. dorsal POC with visuomotor-related nuclei, and appear to suggest that the middle region, which receives input from the iFEF, has greater access to the optokinetic (OKN) system by virtue of its projection to the LTN, and to the smooth-pursuit system b

Afferent Pathways↗
PubMed1990

Origins of uncrossed retinofugal projections in normal and hypopigmented mice.

In albinos, the retinofugal projections to the ipsilateral side of the brain are reduced (e.g., see Guillery, 1969; La Vail et al., 1978; Lund, 1965). Although all ganglion cell types are affected, in mice the displaced ganglion cell population is the main target of the albino mutation (Dräger & Olsen, 1980). Here we tested whether this preferential effect on displaced ganglion cells is a general consequence of the melanin reduction or a pleiotropic effect unique to the albino locus, by retrogradely tracing retinal ganglion cells in normal C57BL/6J mice and in several non-allelic hypopigmentation mutants on the same background: albino (C57BL/6J-c2J), beige (C57BL/6J-bg), pale ear (C57BL/6J-ep), ruby-eye/haze (C57BL/6J-ru-2hz), and pearl (C57BL/6J-pe). All mutants have lower overall cell counts in the ipsilateral projection, but the displaced population is disproportionately affected: the albinos contain 42% of the normal number of displaced ganglion cells, and the other mutants have an average 57% of normal counts. The reduction in uncrossed retinofugal projections in albinos affects the inputs to the lateral geniculate nucleus and the superior colliculus, but not to the suprachiasmatic nucleus (Dräger, 1974). To address the question in which way the susceptible uncrossed projections differ from the nonsusceptible one, we compared ganglion cells backfilled from the suprachiasmatic nucleus to ganglion cells backfilled from the optic tract at geniculate level. Whereas the uncrossed optic tract projection originates from the binocular region in the ventro-temporal retina and contains a high fraction of large and displaced ganglion cells (Dräger & Olsen, 1980), both the crossed and uncrossed inputs to the suprachiasmatic nucleus originate from the entire retina with a relative preference for the lower nasal region that corresponds to part of the monocular visual field; all ganglion cells projecting to the suprachiasmatic nucleus are of medium size, and they are located in the ganglion cell layer. These observations allow the following conclusions: (1) All genetic mutants which cause a reduction in ocular melanin, regardless of the molecular or cell-biological mechanism underlying the pigment reduction, result in decreased uncrossed projections; this confirms previous reports (La Vail et al., 1978, Sanderson et al., 1974). (2) The decrease affects only projections involved in binocular vision. (3) In mice, the ganglion cells displaced to the inner nuclear layer, and hence located closer to the retinal pigment epithelium, are disproportionately affected by the melanin reductions. These observations may provide cues to the spatio-temporal mechanism of the

Afferent Pathways↗
PubMedDate not supplied

Organization of the hamster intergeniculate leaflet: NPY and ENK projections to the suprachiasmatic nucleus, intergeniculate leaflet and posterior limitans nucleus.

The intergeniculate leaflet (IGL) is an integral part of the circadian visual system. It receives direct retinal input and relays photic information to the circadian clock in the suprachiasmatic nucleus (SCN) through a geniculohypothalamic tract (GHT). In both rat and hamster, neuropeptide Y immunoreactive (NPY-IR) IGL cells project through the GHT to the SCN. However, the hamster GHT also contains enkephalin-IR (ENK-IR) fibers, presumably of IGL origin. In the present investigations, the IGL was examined for NPY-, ENK-, or dual-IR cells. Their projections to the SCN, contralateral IGL and pretectum were also studied. The results show that the hamster IGL contains both NPY- and ENK-IR neurons and that about 50% of these are immunoreactive to both peptides. Double-label retrograde analysis indicates that cells of each peptide class project to the SCN. Similarly, IGL neurons, many of which are NPY- and ENK-IR, project to the pretectum, particularly the posterior limitans nucleus. While numerous IGL neurons project contralaterally, very few are NPY- or ENK-IR. The distribution of SCN- and pretectum-projecting cells, in conjunction with the distribution of peptide-IR neurons, allows expansion of the IGL definition to include the region medial to the ventral lateral geniculate nucleus (VLG). The VLG is ventrolateral to the IGL and does not contain either neurons projecting to the SCN nor NPY- or ENK-IR cells, but does have numerous neurons projecting to the pretectum. The results substantiate and expand the previous definition of the hamster IGL, elaborate the species difference in IGL organization, and demonstrate the increased breadth of the circadian visual system.

Afferent Pathways↗
PubMed2001

Recent trends and future projections of lymphoid neoplasms--a Bayesian age-period-cohort analysis.

OBJECTIVES: A steady increase in incidence of lymphoid neoplasms has been reported, especially for non-Hodgkin's lymphoma (NHL). Using high-quality incidence data from 1973-1992 in nine population-based cancer registries (Alberta, Bombay, Denmark, Israel, New Zealand, Osaka, Oxford, Slovenia, Utah), we have examined past increases in specific lymphoid neoplasms. Further, by using a Bayesian age-period-cohort approach, we have calculated 5-, 10- and 15-year projections for each group of lymphoid neoplasms. RESULTS: NHL incidence increased in all centers by an average of 77% in men and 66% in women between 1973 and 1992. Fifteen-year projections of these rates to 2003-2007 indicate that they will increase by an average of 55% among men and 79% among women. High projected incidence rates above 15/100,000 in men and 10/100,000 in women are expected in Alberta, Denmark, Israel, New Zealand, Oxford, and Utah by 2003-2007. The one notable exception was among men from Osaka, where no increase was projected. Modest increases in leukemia and multiple myeloma rates were observed in most of the nine registries with further projected increases by 2007. Projected incidence rates of Hodgkin's disease indicated little change. CONCLUSION: Increases in NHL rates are occurring worldwide and provide no evidence of peaking. A key assumption in the projected rates is that the effect of environmental agents determining the trends during 1973-1992 will remain stable during the subsequent projection period.

Age Factors↗
PubMed2002

Long-term visual outcomes in the Cataract-Free Zone Project in Brazil.

PURPOSE: To determine the long-term visual outcomes and causes of poor vision in the cataract population in Brazil treated in the Cataract-Free Zone Project. METHODS: Project A subjects (62 patients) were recruited in Taquaritinga, SP, 26 months after surgery. Project B subjects (34 patients) were recruited in São João da Boa Vista, SP, 43 months after surgery. All patients underwent visual screening and eye examination (examination 1). They were classified according to visual acuity in the operated eye and the causes of poor vision were diagnosed and referred for treatment. The results of these interventions were collected (examination 2) and analysed by Chi-square test. RESULTS: At examination 1 in project A, 47 of 62 patients (75.6%) had visual acuity < or = 20/100. The main causes of poor vision were refractive error (31.9%) and posterior capsule opacification (17.0%), with or without refractive error. At examination 1 in project B, 22 of 34 patients (64.7%) had visual acuity < or = 20/100. The main causes of poor vision were again posterior capsule opacification (50.0%) and refractive error (9.0%). After posterior capsulotomy with Nd:YAG laser and prescription of new corrective eyeglasses, visual acuity = 20/80 was obtained in 64.5% of patients in project A (OR = 0.18, CI = 0.07-0.41) and 70.5% of patients in project B (OR = 0.19, CI = 0.06-0.60) at examination 2. The causes of blindness in the remaining patients were identified. CONCLUSION: This type of project is effective in reducing blindness caused by cataracts in developing countries. However, long-term scheduled follow-up of operated patients is an effective means of avoiding consecutive blindness resulting from secondary cataracts and refractive changes.

Aged↗
PubMed2001

Projections from the nociceptive area of the central nucleus of the amygdala to the forebrain: a PHA-L study in the rat.

The lateral capsular division (CeLC) of the central nucleus (Ce) of the amygdala, in the rat, has been shown to be the main terminal area of a spino(trigemino)-parabrachio-amygdaloid nociceptive pathway [Bernard & Besson (1990) J. Neurophysiol. 63, 473-490; Bernard et al. (1992) J. Neurophysiol. 68, 551-569; Bernard et al. (1993) J. Comp. Neurol. 329, 201-229]. The projections to the forebrain from the CeLC and adjacent regions were studied in the rat by using microinjections of Phaseolus vulgaris leucoagglutinin (PHA-L) restricted in subdivisions of the Ce and the basolateral amygdaloid nucleus anterior (BLA). Our data showed that the entire CeLC projects primarily and extensively to the substantia innominata dorsalis (SId). The terminal labelling is especially dense in the caudal aspect of the SId. The other projections of the CeLC in the forebrain were dramatically less dense. They terminate in the bed nucleus of the stria terminalis (BST) and the posterior hypothalamus (pLH). No (or only scarce) other projections were found in the remaining forebrain areas. The Ce lateral division (CeL) and the Ce medial division (CeM), adjacent to the CeLC, also project to the SId with slightly lower density labelling. However, contrary to the case of the CeLC, both the CeL and the CeM extensively project to the ventrolateral subnucleus of the BST (BSTvl) with a few additional terminals found in other regions of the lateral BST. Only the CeM projects densely to both the interstitial nucleus of the posterior limb of the anterior commissure and the caudal most portion of the pLH. The projections of the BLA are totally different from those of the Ce as they terminate in the dorsal striatum, the accumbens nucleus, the olfactory tubercle, the nucleus of olfactory tract and the rostral pole of the cingulate/frontal cortex. This study demonstrates that the major output of the nociceptive spino(trigemino)-parabrachio-CeLC pathway is to the SId. It is suggested that the CeLC-SId pathway could have an important role in anxiety, aversion and genesis of fear in response to noxious stimuli.

Amygdala↗
PubMed2000

Evaluation of tuned-aperture computed tomography depth discrimination for image series acquired variously with linear horizontal, linear vertical, and conical beam projection arrays.

OBJECTIVE: To compare depth discrimination by using tuned-aperture computed tomography (TACT) variously with linear horizontal, linear vertical, combined linear horizontal and linear vertical, and conical beam projection arrays. STUDY DESIGN: The first test object was a metallic mesh angled at 30 degrees to the surface of a computed dental radiography size No. 1 x-ray sensor. The second test object was a dry human mandible. The sensor was mounted on an optical bench constructed to permit free and precise geometrical settings for the horizontal and vertical angulations of the x-ray beam. The extent of blurring of horizontal and vertical wires in each TACT reconstructed image slice was observed for each of the tested beam projection arrays. RESULTS: With a linear horizontal beam projection array, it was not possible to determine the depth of structures parallel to the horizontal dimension, such as the mandibular canal. With a linear vertical beam projection, it was not possible to determine the depth of structures parallel to the vertical dimension. A conical array of beam projections was best suited to the task of depth discrimination of objects in all planes. The best second alternative was a combination of linear vertical and linear horizontal projections. CONCLUSIONS: Beam projection geometry is important for the accurate depth discrimination of TACT reconstructed images. A conical beam projection array is ideal.

Dental Alloys↗
PubMed2002

The value of Waters' projection for assessing maxillary sinus inflammatory disease.

OBJECTIVE: The significance of the Waters' projection for judging maxillary mucosal disease is, at the least, questionable. The aim of this study was to evaluate the diagnostic use of Waters' projection of the maxillary sinus with particular regard to sinus mucosal swelling as a consistent sign of maxillary sinusitis. STUDY DESIGN: Forty consecutive adult patients were referred to an ear, nose, and throat surgeon for pain in the region of the paranasal sinus, recurrent mucopurulent rhinorrhea, and nasal congestion or obstruction for at least 3 months without any response to conservative treatment. Both conventional radiographs (Waters' projection) and coronal and axial computed tomography (CT) scanning of the maxillary sinuses were recorded. The conventional radiographs and CT scans, all made within an hour, were blinded and assessed in random order by 2 independent well-trained observers with standard radiodiagnostic criteria for sinus mucosal swelling. Intraobserver and interobserver agreements were quantified by calculating Cohen's kappa. The diagnostic significance of the Waters' projection was assessed with the CT scan images as criterion standard by calculating sensitivity and specificity, positive predictive value, likelihood ratio, and diagnostic odds ratio. RESULTS: Cohen's kappa for the intraobserver agreement of Waters' examination was 0.96, and the intraobserver agreement for CT scanning was 0.92. The interobserver agreement for Waters' projection and CT scanning was 0.76 and 0.92, respectively. With CT scanning as criterion standard, the sensitivity and specificity of Waters' projections to detect maxillary sinus mucosal swelling were 83.3% and 69.2%, respectively. The positive predictive (diagnostic) value of Waters' projections was 83.3%, the positive likelihood ratio 2.7, and the diagnostic odds ratio 11.25. CONCLUSIONS: From this study it can be concluded that Waters' projections do not necessarily rule out the presence of maxillary sinus mucosal swelling. Additional examinations may be indicated, especially in patients with compromised sinus clearance.

Adult↗
PubMed1991

Evidence for separate pathways within the tecto-geniculate projection in the tree shrew.

Two layers (3 and 6) in the dorsal lateral geniculate nucleus (GLd) of the tree shrew (Tupaia belangeri) receive projections from the superficial layers of the superior colliculus. The goal of this study was to determine whether the same or different cells in the superior colliculus give rise to the projections to layers 3 and 6 by following individual axons labeled with biocytin from the superior colliculus to the GLd. The results show that the terminal fields differ in the two layers--those in layer 3 are restricted to a line of projection, whereas those in layer 6 are elongated along the dimension orthogonal to a line of projection. Another important difference between axons that project to GLd layers 3 and 6 is that those that project to layer 6 give off collaterals to the posterior pretectal nucleus, whereas at least some axons that project to layer 3 send a collateral to the ventral lateral geniculate nucleus (GLv). These results suggest that the superior colliculus exerts separate influences on these two GLd layers, both of which project to separate targets above layer IV in the striate cortex. The biocytin method has proved useful by showing the dendritic trees of the superior colliculus cells of origin, the pathways taken by the axons (including the presence of collaterals), and the terminal fields both within and outside the GLd.

Animals↗