Search PubMed⌕ Search

Biomedical subjects

J L Price

Publications and source records attributed to J L Price.

At least 109 records · Page 6Linked to original sources
PubMed1987

Sources of presumptive glutamergic/aspartergic afferents to the rat ventral striatopallidal region.

The distribution of presumptive glutamergic and/or aspartergic neurons retrogradely labeled following injections of 3H-D-aspartate (3H-D-Asp) into the ventral striatopallidal region was compared with the distribution of neurons labeled by comparable injections of wheat germ agglutinin-horseradish peroxidase (WGA-HRP). The afferents labeled by 3H-D-Asp were a subset of those labeled by WGA-HRP. The major sources of afferents to the nucleus accumbens and olfactory tubercle that could be labeled by 3H-D-Asp were in the medial frontal and insular cortices; the olfactory cortex; the lateral, basolateral, and basomedial amygdaloid nuclei; and the midline nuclear complex of the thalamus. The corresponding afferents to the ventral pallidum arose in the central, medial, and basomedial amygdaloid nuclei and the midline thalamic nuclei. In addition, the nucleus of the lateral olfactory tract was moderately or heavily labeled by 3H-D-Asp injections into all three areas, and cells were labeled in the subiculum following injection in the anteromedial part of the nucleus accumbens. Conversely the ventral striatopallidal structures themselves were, at best, sparsely labeled by any of the 3H-D-Asp injections. Neurons in the substantia nigra, ventral tegmental area, dorsal raphe, and locus coeruleus were labeled by WGA-HRP but not by 3H-D-Asp, except for an occasional cell in the raphe. The results indicate that 3H-D-Asp is a specific retrograde tracer and suggest that there are widespread, presumably excitatory, glutamergic and/or aspartergic inputs to the ventral striatum and pallidum.

Animals↗
PubMed1987

The afferent input to the magnocellular division of the mediodorsal thalamic nucleus in the monkey, Macaca fascicularis.

The origin and termination of fibers to the mediodorsal thalamic nucleus, especially those to the medial, magnocellular part of the nucleus (MDm), have been studied using anterograde and retrograde axonal tracing methods, as well as electrophysiological recording. The results indicate that in addition to its well-known connections to and from the prefrontal cortex, MDm receives fibers from many parts of the basal forebrain, including the ventral pallidum and other parts of the substantia innominata, the amygdaloid complex, the primary olfactory cortex, entorhinal and perirhinal cortex, and the cortex at the pole of the temporal lobe. Lighter projections arise in the subiculum, the ventral insula, and the superior and inferior temporal gyri. The cells that project to MDm tend to be large, polymorphic neurons. Throughout most of the basal forebrain they are diffusely distributed through several nuclei or cortical layers, without obvious relation to nuclear or laminar boundaries. The major exception to this is in the ventral pallidum, where there is a dense concentration of cells that project to MDm. The lateral part of the mediodorsal nucleus (MDl) receives few if any fibers from the basal forebrain and temporal lobe, but is innervated by several brainstem structures, especially the superior colliculus, the substantia nigra, the medial vestibular nucleus, and the midbrain tegmental fields. In MDm, the fibers are distributed in irregular patches. Three-dimensional analysis indicates that these patches are often clustered into separate bands or columns at different anteroposterior levels. In addition, the strongest projections from the three major regions that innervate MDm are organized in a complex three-dimensional pattern. First, the fibers from the amygdaloid nuclei terminate most heavily (but not exclusively) in the rostral third of MDm. The parvicellular accessory basal amygdaloid nucleus and the amygdalohippocampal area project principally to the dorsal part of the nucleus. The parvicellular basal nucleus and the periamygdaloid cortex project to the ventromedial quadrant of MDm; and the magnocellular basal nucleus, the magnocellular accessory basal nucleus, and the lateral nucleus all project to the ventrolateral quadrant. Second, the substantia innominata projects preferentially to the caudal part of MDm. The medial part of the substantia innominata, especially the ventral pallidum, innervates the dorsomedial quadrant, while more caudal and lateral areas of this region project ventrolaterally. Third, the projections arising from the entorhinal and other temporal cortical areas terminate primarily in the mid-rostrocaudal level of MDm.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1986

The distribution of choline acetyltransferase in the rat amygdaloid complex and adjacent cortical areas, as determined by quantitative micro-assay and immunohistochemistry.

The distribution of choline acetyltransferase (ChAT) within the amygdaloid complex has been studied to evaluate what should primarily represent the terminal field of the cholinergic projection from the basal forebrain. Two currently available methods have been combined for the comparison: immunohistochemistry with a monoclonal antibody against ChAT, by a double peroxidase-antiperoxidase procedure, and quantitative histochemistry involving micro-assay of the ChAT activity of contiguous microdissected samples. Both methods indicate prominent ChAT activity in the basolateral amygdaloid nucleus (especially rostrally), the nucleus of the lateral olfactory tract (especially layer II), and the amygdalohippocampal area. Regions of lower ChAT activity were not accurately represented by the immunohistochemistry, but could be discriminated by the quantitative assays. Lowest activity was found in the medial nucleus of the amygdala. Most other regions had activities at least as high as average brain or neocortex. Gradients of enzyme activity were found within several regions, including the basolateral and lateral amygdaloid nuclei and the nearby posterior piriform cortex. In the piriform cortex, a region of particularly high ChAT activity was found at its medial edge near the nucleus of the lateral olfactory tract. The immunohistochemical method shows a few intensely reactive somata in layer III within this zone. Comparison of the results seen with immunohistochemistry and quantitative histochemistry suggests an advantage in using them together, since their respective strengths and weaknesses tend to complement each other.

Amygdala↗
PubMed1986

Plasticity in the olfactory cortex: age-dependent effects of deafferentation.

In order to assess the role of input-target interactions in the development of olfactory cortex, the primary afferent fibers from the olfactory bulb to the superficial part of layer I of the cortex (layer Ia) were removed in developing and mature rats. After survival periods that vary from a few days to 2-6 months, changes were assessed in (1) the radial thickness of layer I, (2) the laminar distribution of intracortical associational fibers, which normally terminate in a deep part of layer I (layer Ib), and (3) the distribution of glia in layer I. The findings indicate that the lamination of fibers within layer I is not intrinsically prespecified, but gradually becomes "set" during the first month after birth. If the fibers from the olfactory bulb are removed, the dendrites of cortical cells are capable of accepting inputs from other fiber systems, depending on the maturational state of the dendrites and the ingrowing axons. Development of the abnormal inputs is associated with relatively normal dendritic growth, whereas lack of adequate input results in dendritic atrophy. Thus, after neonatal bulb ablation, the intracortical fibers occupy both superficial and deep parts of layer I, and a normal synaptic density is established throughout the layer. Layer I also develops to nearly its normal adult thickness, although the high density of glia that normally characterizes layer Ia is not apparent. With bulb ablation at progressively older ages (from postnatal day (P-) 3 to 21), the cortical associational fibers show progressively less extension into the denervated layer Ia. Layer I continues to grow, but not to the same extent as after P-1 ablations. In these experiments the glia distribution resembles the pattern present at the time of denervation. After adult olfactory bulb ablation, the long intracortical fibers extend very little into layer Ia, which undergoes pronounced shrinkage and becomes filled with a high concentration of glia. However, partial reinnervation of layer Ia is accomplished by the proliferation of a normally sparse native fiber system, which has been identified only with the Timm method. These results are interpreted as evidence that the normal development of lamination of afferent fibers to the olfactory cortex depends on axodendritic interaction during development.

Age Factors↗
PubMed1986

Age-dependent cell death in the olfactory cortex: lack of transneuronal degeneration in neonates.

Adult olfactory cortical neurons in layer IIa undergo fulminant transneuronal degeneration after removal of afferent olfactory bulb fibers (Price, '76, Neurosci Abst. 2:161; Heimer and Kalil, '78, J. Comp. Neurol. 178:559-609). This provides an unusual example of dependence of a mature population of neurons on axonal input. In order to investigate whether similar transneuronal degeneration occurs in immature animals, a series of rats were subjected to unilateral olfactory bulb removal at various ages during the first 3 postnatal weeks. The brains were examined for degeneration after short survivals by use of the de Olmos cupric silver method, which selectively stains degenerating neurons. In addition, animals with long survivals were examined with the HRP retrograde tracing method, in order to determine if cells that survive the acute effects of deafferentation develop normal patterns of connections. Young neurons are more resistant to the effects of olfactory bulb removal than more mature neurons. There was little degeneration of cortical neurons after bulb ablation during the first 2 postnatal weeks. Although layer IIa does not become distinct from layer IIb in these experimental animals, cells that have connections normally characteristic of the cells of layer IIa, and are situated at the superficial edge of layer II, were identified with the HRP method. The severity of transneuronal degeneration increases and becomes adultlike between the second and third postnatal weeks. This increase in transneuronal degeneration is temporally associated with a progressive reduction in axonal sprouting following deafferentation during the first 3 postnatal weeks, as described in the companion paper (Friedman and Price, '86). Thus, axon sprouting may "protect" the immature IIa neurons from the effects of removal of the fibers from the olfactory bulb. A period of normal cell death has also been identified in olfactory cortex by the use of the de Olmos cupric silver method. This cellular degeneration is much less severe and has a different time course and laminar distribution than the transneuronal degeneration produced by olfactory bulb ablation in adults. Although normal cell death appears to be potentiated by removal of the olfactory bulb on postnatal day 1, it is clearly a different process from the transneuronal reaction.

Age Factors↗
PubMed1986

Thumb reconstruction--an algorithm.

A patient-oriented treatment algorithm was developed to place in perspective the multiple treatment options available for thumb reconstruction. This algorithm was derived from our experience with 52 patients with congenital thumb hypoplasia or aplasia (n = 10) or traumatic amputations (n = 42). The available options for reconstructive treatment include replantation and revascularization, pollicization, microvascular transfer, lengthening, and web space deepening/lengthening. Using this algorithm, a rational decision can be made on the basis of the length of the remaining digit and the associated injuries. Often, patients with as much as 1 cm of proximal phalanx remaining may have good function and sensibility without reconstruction.

Adult↗
PubMed1985

The afferent connections of the substantia innominata in the monkey, Macaca fascicularis.

The afferent connections of the substantia innominata and the magnocellular nuclei within it (the nucleus of the horizontal limb of the diagonal band, NHDB, and the nucleus basalis of Meynert, NBM) have been studied with anterograde and retrograde axonal tracing techniques. Prominent inputs arise in the amygdaloid complex, restricted areas of the cerebral cortex, parts of the thalamus and hypothalamus, and nuclei of the lower brainstem. Autoradiographic tracing experiments indicate that the amygdaloid fibers are distributed throughout the NHDB and the NBM, and to a lesser extent to the ventral pallidum. Relatively few fibers innervate the more medially located nucleus of the vertical limb of the diagonal band (NVDB) and the medial septal nucleus. Visualization of the amygdalofugal fibers with the tracer PHA-L (Phaseolus vulgaris leuco-agglutinin) shows that they have varicosities resembling boutons en passant along their length in the substantia innominata. Retrograde tracing experiments using WGA-HRP indicate that the cells of origin of the projection from the amygdala are concentrated in the parvicellular basal nucleus, the caudal part of the magnocellular basal nucleus, the magnocellular accessory basal nucleus, and the central nucleus. Relatively few fibers to the substantia innominata arise in the rostrodorsal part of the magnocellular basal nucleus, or in the lateral or parvicellular accessory basal nuclei. Cortical cells projecting to the substantia innominata were retrogradely labeled in the orbitofrontal cortex (including areas 11-14 and 25), the rostral insula (especially the agranular area), the rostroventral temporal cortex (including areas 35, 36, and parts of TG and TE), and the piriform and entorhinal cortices. The projections from the orbital and rostral temporal cortex were confirmed with anterograde tracers. Projections to the substantia innominata were not found from the more lateral, dorsal or caudal parts of the cerebral cortex, although fibers from temporal area TA may pass through the dendritic field of the most caudal cells of the NBM. Diencephalic cells projecting to the substantia innominata are distributed diffusely throughout the preoptic area and hypothalamus, with higher concentration in the lateral preoptic area and in the pre-, supra-, and tubero-mammillary nuclei. Cells are also found in the midline thalamic nuclei and in the region between the peripeduncular and subparafascicular nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1985

The amygdalostriatal projections in the monkey. An anterograde tracing study.

Amygdalostriatal projections have been studied in the monkey with the autoradiographic method for demonstrating axonal transport of tritiated amino acids. Amygdaloid fibers were found to project in a roughly topographical manner to widespread areas of the striatum and ventral striatum, including the nucleus accumbens, the striatal-like portions of the olfactory tubercle, ventral portions of the putamen and ventral and caudal parts of the caudate nucleus. The parvicellular part of the basal nucleus and the amygdalohippocampal area appear to be the major sources of fibers to the nucleus accumbens, whereas projections to the tail of the caudate nucleus seem to arise mainly from the magnocellular part of the basal nucleus. In many of these areas, the amygdalostriatal fibers are concentrated in patches.

Amygdala↗
PubMed1985

Determinants of turnover among nursing department employees.

A causal model of turnover, or quitting, among hospital nursing department employees was evaluated. This model includes job satisfaction, organizational commitment, and intent to leave as intervening variables that mediate 13 determinants of turnover. The sample consisted of 841 female nursing department employees selected from five hospitals in a western state. Attitudinal and background data were obtained through a mail questionnaire survey, and turnover was monitored for 18 months following the survey. Intent to leave had a strong direct effect on turnover while kinship responsibility, job satisfaction, and organizational commitment had indirect effects on turnover through intent to leave. Task repetitiveness, autonomy, promotional opportunities, and fairness of rewards were important determinants of jobs satisfaction and thus provide a mechanism whereby hospital management may enhance commitment to the organization while reducing turnover.

Adult↗
PubMed1985

Bacterial colonization of percutaneous sutures.

The direct electron microscopic examination of 15 sutures and 15 staples removed from 10 healed surgical wounds showed, on the intradermal portions, consistent colonization by bacteria growing in adherent biofilms. This clearly demonstrable bacterial colonization of biomaterials within the wound tract had not resulted in infection or perceptible inflammation in any of the wounds. These bacterial cells were of several morphotypes, including gram-positive cocci, and all specimens yielded cultures of the autochthonous (native) skin bacterium, Staphylococcus epidermidis. The bacteria within the wound tracts were enveloped by extracellular material that appeared on scanning electron microscopy to be a condensed amorphous residue and on transmission electron microscopy to be a fibrous extracellular matrix. We suggest that this mode of growth, in which the colonizing bacteria are enveloped in a copious exopolysaccharide glycocalix, protects the bacteria from host defense factors and accounts for their persistence on the suture surfaces until they are removed with the sutures.

Bacillus↗
PubMed1984

Amygdalo-cortical projections in the monkey (Macaca fascicularis).

Amygdalo-cortical projections were analyzed in the macaque monkey (Macaca fascicularis) in a series of experiments in which 3H-amino acids were injected into each of the major divisions of the amygdaloid complex and the anterogradely transported label was demonstrated autoradiographically. Projections to widespread regions of frontal, insular, temporal, and occipital cortices have been observed. The heaviest projections to frontal cortex terminated in medial and orbital regions which included areas 24, 25, and 32 on the medial surface and areas 14, 13a, and 12 on the orbital surface. Lighter projections were also seen in areas 45, 46, 6, 9, and 10. The heaviest projection to the insula terminated in the agranular insular cortex with a decreasing gradient of innervation to the more caudally placed dysgranular and granular insular areas. The projection to this region continues around the dorsal limiting sulcus to terminate in the somatosensory fields 3, 1-2, and SII. Essentially all major divisions of the temporal neocortex receive a projection from the amygdaloid complex with the most prominent projections ending in the cortex of the temporal pole (area TG) and the perirhinal cortex. The entire rostrocaudal extent of the inferotemporal cortex (areas TE and TEO) is also in receipt of an amygdaloid projection. While the rostral superior temporal gyrus (area TA) is heavily labeled in several of the experiments (with light labeling continuing into AI and adjacent auditory association regions) there was little indication of labeling in the caudal reaches of area TA. There was a surprisingly strong projection to prestriate regions of the occipital lobe and, in at least one case, clear-cut labeling in areas OB and 17. Labeling in the parietal cortex was primarily observed in the depths of the intraparietal sulcus. In all cortical fields, label was heaviest at the border between layers I and II and in some regions layers V and VI also had above background levels of silver grains.

Amygdala↗
PubMed1984

Amygdalostriatal projections in the rat. Topographical organization and fiber morphology shown using the lectin PHA-L as an anterograde tracer.

Amygdalostriatal projections in the rat were studied with the anterograde tracer phaseolus vulgaris leucoagglutinin (PHA-L), which allows direct visualization of axon morphology. The appearance of fibers in the striatum which were labeled from injections into the amygdaloid complex suggests that they form 'en passant' synapses. A topographic organization was found in the projection from the basolateral amygdaloid nucleus: the most caudal part of this nucleus projects to the anteromedial edge of the striatum, including the medial nucleus accumbens, while progressively more rostral parts of the nucleus project to more lateral and caudal portions of the striatum. No amygdaloid fibers were found in the most rostro-dorsolateral part of the caudatoputamen.

Amygdala↗
PubMed1984

The development of axonal connections in the central olfactory system of rats.

The development of the cytoarchitecture and axonal connections of the central olfactory system were studied in fetal and neonatal rats from E16. In contrast to neocortical development, the olfactory cortex lacks a distinct cortical plate. In the piriform cortex and the olfactory tubercle the cellular laminae emerge simultaneously, while in the anterior olfactory nucleus, there are morphogenetic gradients from superficial to deep as well as from caudal to rostral which parallel the known cytogenetic gradients. Parallel morphogenetic and cytogenetic gradients are also present in the lateral to medial axis of the olfactory tubercle. The projection from the olfactory bulb and the associational projections from the piriform cortex begin to develop well before birth. At E17 fibers from the bulb are limited to the lateral olfactory tract (LOT) and the molecular layer just deep to it, and then spread out caudally, laterally, and medially away from the LOT. This sequence of innervation parallels and predicts the density of innervation in the adult: those areas which are innervated first (such as the piriform cortex deep to the LOT) ultimately receive the heaviest innervation; conversely, those areas which are innervated very late (such as the medial olfactory tubercle) receive the lightest projection. The intracortical projections from the anterior and posterior piriform cortex extend into layer I ipsilaterally by E20 and obtain their adult distribution by the middle of the first postnatal week. On the other hand, fibers from the anterior olfactory nucleus and the entorhinal area do not reach their full adult extent until the second postnatal week. Similarly, the crossed projection of the anterior piriform cortex to the contralateral posterior piriform cortex does not grow into layer I until this later time. The timing of fiber ingrowth showed no relation to the trajectory or eventual areal or laminar termination of fibers. As with the olfactory bulb projection, the timing may influence the density of termination. Centrifugal fibers to the bulb are demonstrable around the time of birth both by the retrograde transport of horseradish peroxidase (HRP) and by the anterograde transport of 3H-leucine. The arrival of additional fibers during the remainder of the first postnatal week parallels the known cytogenetic and morphogenetic gradients in the areas in which they arise. The projections of the olfactory cortex to the lateral hypothalamic area and the mediodorsal thalamic nucleus are evident before birth. This correlates with the early generation of the cells which give rise to these projections.

Aging↗