bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical localization of substance P and enkephalin in the nucleus tractus solitarii of the rhesus monkey, Macaca mulatta
Authors: Maley Bruce E. , Newton Bruce W. , Howes Kimberly A. , Herman Linda M. , Oloff Clarence M. , Smith Katherine C. , Elbe Robert P. 
Published: January 2005

AbstractThe nucleus tractus solitarii in the monkey Macaca mulatta was found to have several subdivisions based upon cytoarchitectonics and immunohistochemistry. Subdivisions that could be identified included commissural, medial, parvicellular, dorsolateral, ventrolateral, intermediate, and interstitial. Substance P and enkephalin immunoreactivity was localized within discrete regions of the nucleus tractus solitarii, by means of the peroxidase‐antiperoxidase technique. Substance P immunoreactivity occurred most frequently in the interstitial subdivision of the nucleus tractus solitarii. Moderate accumulations of substance P immunoreactivity were present in the commissural, medial, parvicellular, dorsolateral, and intermediate subdivisions, but very little was present in the ventrolateral subdivision. Enkephalin immunoreactivity followed the staining patterns of substance P; however, the amounts of enkephalin immunoreactivity were less than amounts for substance P. Following colchicine treatment, large numbers of enkephalin‐immunoreactive neurons were distributed throughout all subdivisions, many being located in the parvicellular and medial subdivisions. The few substance P‐immunoreactive neurons found were restricted to the parvicellular subdivision. The distribution of substance P and enkephalin immunoreactivity in M. mulatta is very similar to that described in the cat and rat. In addition, the extensive overlap of the distribution of these two putative neurotransmitters provides morphological evidence for their possible participation in the autonomic regulation within the nucleus tractus solitarii.
Convergence of ascending pathways at the inferior colliculus of the mustache bat, pteronotus parnellii
Authors: Zook J. M. , Casseday J. H. 
Published: January 2005

AbstractTo compare patterns of projections to the inferior colliculus from different sources, injections of [3H]‐leucine were placed in the cochlear nuclei, superior olivary complex, and nuclei of the lateral lemniscus of Pteronotusc parnellii. The results show that the target of the anteroventral cochlear nucleus (AVCN) is the ventral and lateral two thirds of the central nucleus of the inferior colliculus. The binaural pathways from the medial and lateral superior olives (MSO and LSO) project to the same target. The dorsal cochlear nucleus (DCN) projects to the entire central nucleus of the inferior colliculus and does so in a more diffuse manner than does the AVCN. The DCN also sends sparse projections beyond the central nucleus into dorsal parts of the pericentral area. The intermediate (INLL) and ventral (VNLL) nuclei of the lateral lemniscus are relays in pathways that originate in the cochlear nucleus and terminate in the contralateral inferior colliculus. These nuclei also receive indirect input from the contralateral AVCN via the medial nucleus of the trapezoid body. Although nuclei of the lateral lemniscus project most densely to those areas of the inferior colliculus that are also the targets of the AVCN, MSO, and LSO, the nuclei of the lateral lemniscus also send spare projections outside these areas. Many of the pathways just described project in bands, a finding that raises the possibility that the projections parallel the orientation of disk‐shaped cells in the inferior colliculus and raises the question of whether the bands from one source overlap or interdigitate with the bands from another source.
Mapping study of serotoninergic input to diencephalic‐projecting dorsal column neurons in the rat
Authors: Willcockson H. H. , Carlton S. M. , Willis W. D. 
Published: January 2005

AbstractSeveral lines of evidence indicate that the processing of somatosensory information in the dorsal column nuclei (DCN) is subject to descending controls. Anatomical experiments have demonstrated projections to the DCN from the sensorimotor cerebral cortex and the reticular formation. Physiological studies have shown that the activity of DCN neurons can be altered following stimulation of the cerebral cortex, reticular formation, periaqueductal gray, or raphe nuclei. Recent biochemical and electrophysiological evidence suggests a serotoninergic modulation of DCN neurons. The present study identifies serotonin‐containing contacts on cells in the DCN that project to the thalamus in the rat. Retrograde labeling of brainstem neurons by horseradish peroxidase demonstrated projections to the DCN from the nucleus reticularis paragigantocellularis lateralis and from several raphe nuclei, including nuclei raphe obscurus (RO), pallidus (RP), and magnus (RM). Double labeling with horseradish peroxidase and antibody for serotonin indicated that the RO, RP and RM are likely to be the sources of the serotoninergic projections to the DCN. Thus, the role of the serotoninergic output from the raphe nuclei includes modulation of activity in the DCN.
Ultrastructure of apical specializations of taste cells in the mudpuppy, Necturus maculosus
Authors: Cummings T. A. , Delay R. J. , Roper S. D. 
Published: January 2005

AbstractThe first interaction of taste stimuli with lingual chemoreceptors occurs on the apical membrane of taste cells, since only that portion is exposed to the oral cavity. To gain better insight into this interaction, we examined the pore region of taste buds in Necturus maculosus with scanning electron microscopy (SEM), transmission electron microscopy, and high‐voltage electron microscopy. SEM of the pore reveals a patchwork distribution of three morphologically distinct types of apical specializations: long and branched (LB) microvilli, short and unbranched (SU) microvilli, and bundles of sterocilia. As demonstrated in thin and thick sections, LB microvilli are specializations of dark cells, SU microvilli are the apical specializations of light cells, and stereocilia arise from a cell that has the cytoplasmic markers characteristic of light cells. When left in place, the pore mucus completely covers the SU microvilli and partially covers the LB microvilli. However, stereocilia project above the surface and thus are highly exposed to taste stimuli in the oral cavity. These three morphologically distinct types of apical specializations may reveal functional differences among taste cells. The initial interaction between chemical stimulus and taste cell, and possibly chemoreceptor specificity itself, may be influenced by the morphology of the apical ending.
Developmental and other factors affecting regeneration of crayfish CNS axons
Authors: Seshan Kalpathi R. , Bittner George D. 
Published: January 2005

AbstractAccording to histological and ultrastructural criteria, nongiant CNS axons in newly hatched crayfish regenerate more rapidly and with greater frequency than do similar axons in adult crayfish.Regenerative ability is greater in one species (Procambarus clarkii) than in another species (Procambarus simulans), is greater at 20–25°C than at 15–16°C, and is greater in nongiant axons than in giant axons. In contrast to axonal regeneration, nerve cell bodies do not regenerate in newly hatched or adult crayfish of either species. While the ability to regenerate CNS axons differs between newly hatched and adult crayfish, the ultrastructural appearance of the CNS is very similar at any age it is examined.
Immunohistochemical localization of calcium‐binding proteins, parvalbumin and calbindin‐D 28K, in the adult and developing visual cortex of cats: A light and electron microscopic study
Authors: Stichel C. C. , Singer W. , Heizmann C. W. , Norman A. W. 
Published: January 2005

AbstractIn the cat primary visual cortex, we investigated with immunohistochemical techniques the developmental changes in the cellular and subcellular localization of the Ca2+‐binding proteins parvalbumin (PV) and calbindin‐D 28K (CBP), in order to determine whether there is a correlation between the expression of Ca2+‐dependent processes and the time course of the critical period for use‐dependent plasticity.On the 54th day of gestation and at 1 week postnatally, both calcium‐binding proteins were present only in a subpopulation of neurons in layers V and VI. During subsequent maturation, the number of PV(+) and CBP(+) neurons increased significantly and labeled cells were detected in more superficial layers. Moreover, the homogeneous labeling of some CBP(+) neurons in layers IV to VI decreased and changed to a punctate pattern. In adult cats PV(+) neurons were evenly distributed throughout layers II to VI, whereas CBP(+) neurons were concentrated in layers II/III. Only a few immunoreactive cells had morphological features characteristic of pyramidal cells; the large majority were nonpyramidal.Electron microscopy confirmed the presence of PV‐ and CBP‐reaction product within the perikarya, axons, and dendrites of labeled cells. It was associated preferentially with microtubules, postsynaptic densities, and intracellular membranes. Immunoreactive neurons received immunonegative asymmetric synapses on their dendritic shafts and made symmetric synaptic contacts with labeled and unlabeled somata and with unlabeled dendritic shafts.The large number and widespread distribution of immunoreactive neurons implies that PV and CBP play an important role in the regulation of calcium‐dependent processes in the visual cortex. Furthermore, the developmental redistribution of PV and CBP points to changes in the organization of Ca2+‐dependent processes during maturation.
Localization of tyrosine hydroxylase immunoreactive neurons in the cat hypothalamus, with special reference to fluorescence histochemistry
Authors: Kitahama Kunio , Luppi Pierre‐Herve , Berod Anne , Goldstein Menek , Jouvet Michel 
Published: January 2005

AbstractThe present study examines the distribution and morphological characteristics of neurons containing immunoreactivity of tyrosine hydroxylase in the cat hypothalamus. We used the indirect immunoperoxidase technique on vibratome sections. Tyrosine hydroxylase immunoreactive cell bodies were widely distributed in discrete regions of the cat hypothalamus. Several principal cell groups were identified. They were seen in the posterior and dorsal hypothalamic areas, zona incerta, dorsomedial and lateral hypothalamic areas, arcuate nucleus, periventricular nucleus, paraventricular nucleus, and an area of the tuber cinereum and preoptic area. These cells presented two different morphological characteristics; small with two to three short processes and medium to large, multipolar with three to five long dendritic trees. The atlas is presented in twelve cross‐sectional drawings of the cat hypothalamus from the level A8.5 to A15 of the Horsley‐Clarke stereotaxic planes. We also examined the distribution of hypothalamic catecholamine fluorescent neurons by using the aqueous aldehyde method in combination with glyoxylic acid applied to vibratome sectioned tissues, which improves sensitivity. Comments are made on the relative localizations of the tyrosine hydroxylase‐immunoreactive and aldehyde‐induced histofluorescent cells, as well as on species differences between the cat, rat, and mouse.
Movement of newly synthesized membrane by fast transport along the axon of an identified aplysia neuron
Authors: Cleary Leonard J. , Schwartz James H. 
Published: January 2005

AbstractIn order to ascertain the form in which newly synthesized membrane is moved by fast axonal transport, we examined the distribution of label along an axon of the identified giant, serotoninergic neuron (GCN) in the cerebral ganglion of Aplysia, californica. Membrane glycoproteins were labeled by intrasomatic injection of 3H‐fucose, and segments of GCN's axon in the posterior lip nerve containing the transported organelles were examined at 1, 5, 15, and 24 hours by quantitative electron‐microscopic autoradiography. To show that membrane which is rapidly transported is contained only in discrete organelles rather than in continuous shoots of axoplasmic reticulum, we systematically varied conditions of fixation. We found that we could distinguish vesicles from axoplasmic reticulum most reliably in axons fixed with 2% formaldehyde and 2% glutaraldehyde in cacodylate buffer. At short times after intrasomatic injection of 3H‐fucose, dense‐cored vesicles and multivesicular tubules were the only axonal organelles labeled.
Frontal projections to the region of the oculomotor complex in the rat: A retrograde and anterograde HRP study
Authors: Leichnetz G. R. , Hardy S. G. P. , Carruth M. K. 
Published: January 2005

AbstractThe retrograde and anterograde capabilities of the horseradish peroxidase (HRP) technique were employed to study frontal projections to the perioculomotor region in the rat. Following HRP microinjections or trans‐cannular HRP gel implants into the oculomotor complex (OMC), the majority of retrogradely labeled pyramidal cells were located in lamina V of the dorsomedial frontal shoulder cortex, i.e., medial precentral and anterior cingulate (PrCm/AC) cortices, the proposed frontal eye field (FEF) in the rat. A smaller number of labeled cells were present in the frontal polar cortex, agranular insular (AI), and lateral precentral (PrCl) cortices. Following HRP gel implants into the PrCM/Ac, anterogradely labeled projections were observed to the dorsal medial subthalamic region (nucleus campi Foreli, NCF) and medial accessory nucleus of Bechterew (MAB), and to other subcortical nuclei known to receive inputs from cortical area 8 in the monkey. These results, taken together with previous anatomical and physiological studies, support the conclusion that the PrCm/AC cortex contains the rat FEF. Its homo logy with the primate FEF is discussed.
Motoneuronal death during human fetal development
Authors: Forger Nancy G. , Breedlove S. Marc 
Published: January 2005

AbstractThe total number of ventral horn motoneurons throughout the spinal cord was determined for 19 human fetuses ranging in age from 11 to 32 menstrual weeks. There was a significant (∽35%) decline in motoneuron number between wks 11 and 25 of gestation, but no further decline from wks 25–32. Counts of pyknotic cells indicated a peak of motoneuronal degeneration between about wks 12 and 16 of age. The normal period of motoneuronal death observed here overlaps with the initiation of functional neuromuscular contact as well as the period of androgen production by the human fetal testes. As in rats, androgen may influence final motoneuron number in the human spinal cord by attenuating cell death in sexually dimorphic motor nuclei.
Central projections of the glossopharyngeal and vagal nerves in the channel catfish, Ictalurus punctatus: Clues to differential processing of visceral inputs
Authors: Kanwal Jagmeet S. , Caprio John 
Published: January 2005

AbstractTransganglionic transport of horseradish peroxidase was used to trace the pattern of medullary terminations of the glossopharyngeal and vagal nerve complex in the channel catfish, Ictalurus punctatus. The glossopharyngeal root terminates centrally in the anterior end of the vagal lobe except for two fascicles that terminate in separate regions of the nucleus intermedius of the facial lobe. Vagal nerve branches innervating regions of the oropharynx terminate in an overlapping, segmental fashion throughout the ipsilateral vagal lobe and the nucleus intermedius of the vagal lobe. The descending branch of the vagus, innervating the abdominal viscera, terminates in the general visceral nucleus and in the nucleus intermedius of the vagal lobe. In addition, abdominal visceral fibers decussate through the commissural nucleus of Cajal and terminate in the general visceral nucleus of the contralateral side. Efferents included in the oropharyngeal and abdominal branches of the vagus also originate from two morphologically separable populations of motor neurons.
Differential localization of alkaline phosphatase in barrier tissues of the frog and rat nervous systems: A cytochemical and biochemical study
Authors: Latker Carole H. , Shinowara Nancy L. , Miller Joseph C. , Rapoport Stanley I. 
Published: January 2005

AbstractWe investigated the localization of alkaline phosphatase (AP) in the peripheral and central nervous systems of the frog (Rana pipiens) and rat. In the frog sciatic nerve, AP reaction product was seen as a precipitate within caveolae and vesicular profiles of perineurial cells, and frequently filled the extracellular space. In the rat peripheral nerve, AP reaction product appeared as small tufts on the cell surfaces and within vesicular profiles of endoneurial blood vessels. AP reaction product was not detected in the rat perineurium or in endoneurial blood vessels of the frog. In the frog central nervous system, AP reaction product was detected in the arachnoid membrane adjacent to the subarachnoid space, but not in the cerebral or pial vessels, whereas in the rat it was detected in the outer arachnoid membrane and in the cerebral and pial blood vessels. Biochemical analysis indicated a sevenfold higher AP activity in the frog perineurium over the endoneurium, whereas in the rat, threefold more activity was measured in the endoneurium over the perineurium. Levamisole, an AP inhibitor, decreased the enzyme activity by 95% in rat tissues, and by 70% in frog tissues and in plasma from both animals. Similar decrements were observed cytochemically.This study suggests that: (1) the distribution of AP varies between species, but that it is always present in at least one component of the blood‐brain and blood‐nerve barriers, (2) because barrier tissues of the nervous system have enzymatic activity, they may biochemically modify the adjacent environment, (3) vesicular profiles and caveolae in the blood vessels and perineurium may function as microenvironments for enzymatic activity, and (4) in the rat and frog, different isozymes of AP may be present.
The entorhinal cortex of the monkey: III. Subcortical afferents
Authors: Insausti R. , Amaral D. G. , Cowan W. M. 
Published: January 2005

AbstractThe subcortical afferent connections of the entorhinal cortex of the Macaca fascicularis monkey were investigated by the placement of small injections of the retrograde tracer wheat germ agglutinin conjugated to horseradish peroxidase into each of its subdivisions. Retrogradely labeled cells were observed in several subcortical regions including the amygdaloid complex, claustrum, basal forebrain, thalamus, hypothalamus, and brainstem. In the amygdala, labeled cells were observed principally in the lateral nucleus, the accessory basal nucleus, the deep or paralaminar portion of the basal nucleus, and the periamygdaloid cortex. Additional retrogradely labeled cells were found in the endopiriform nucleus, the anterior amygdaloid area, and the cortical nuclei. Retrogradely labeled cells were observed throughout much of the rostrocaudal extent of the claustrum and tended to be located in its ventral half. In the basal forebrain, retrogradely labeled cells were observed in the medial septal nucleus, the nucleus of the diagonal band, and to a lesser extent within the substantia innominata. Several of the cells in the latter region were large and located within the densely packed neuronal clusters of the basal nucleus of Meynert. Most of the labeled cells in the thalamus were located in the midline nuclei. Many were found in nucleus reuniens, but even greater numbers were located in the centralis complex. Additional labeled cells were located in the paraventricular and parataenial nuclei. In all cases, numerous retrogradely labeled cells were observed in the medial pulvinar. In the hypothalamus, most of the retrogradely labeled cells were located in the supramamillary area, though scattered cells were also observed in the perifornical region and in the lateral hypothalamic area. Caudal to the mamillary nuclei there were labeled cells in the ventral tegmental area. There were relatively few labeled cells in the brainstem and these were invariably located either in the raphe nuclei or locus coeruleus.
Anatomical and physiological characteristics of vestibular neurons mediating the vertical vestibulo‐ocular reflexes of the squirrel monkey
Authors: McCrea R. A. , Strassman A. , Highstein S. M. 
Published: January 2005

AbstractThe morphology of 35 vestibular neurons whose firing rate was related to vertical eye movements was studied by injection of horseradish peroxidase intracellularly into physiologically identified vestibular axons in alert squirrel monkeys. The intracellularly injected cells were readily classified into four main groups. One group of cells, down position‐vestibular‐pause neurons (down PVPs; N = 12), increased their firing rate during downward eye positions, paused during saccades, and were located in the medial vestibular nucleus (MV) and the adjacent ventrolateral vestibular nucleus (VLV). They had axons that crossed the midline and ascended in the medial longitudinal fasciculus (MLF) to terminate in the trochlear nucleus, the lateral aspect of the caudal oculomotor nucleus, and the dorsal aspect of the rostral oculomotor nucleus. A second group of cells (N = 15) were also located in the MV and VLV, but increased their firing rate during upward eye positions, and paused during saccades. These cells had axons that crossed the midline and ascended in the contralateral MLF to terminate in the medial aspect of the oculomotor nucleus. A third group of cells (N = 4) were located in the superior vestibular nucleus, generated bursts of spikes during upward saccades, and increased their tonic firing rate during upward eye positions. These cells had axons that ascended laterally to the ipsilateral MLF to terminate in regions of the trochlear and oculomotor nuclei similar to those in which down PVPs terminated. A fourth group of cells (N = 4), located in the VLV, had axons that projected to the spinal cord, although they had firing rates that were significantly correlated with vertical eye position. Electrical stimulation of the vestibular nerve evoked spikes at monosynaptic latencies in each of the above classses of cells, six of which were injected with horseradish peroxidase.Each group of cells had collateral projections to other areas of the brainstem. Some of the neurons that projected to the contralateral trochlear and oculomotor nuclei had collaterals that crossed the midline to terminate in the oculomotor nucleus ipsilateral to the soma, and some gave rise to small collaterals that terminated in the abducens nucleus. Other areas of the brainstem that received collateral inputs from neurons projecting to oculomotor and trochlear nuclei included the interstitial nucleus of Cajal, the caudal part of the dorsal raphe nucleus, the nucleus raphe obscurus, Roller's nucleus, the intermediate and caudal interstital nuclei of the MLF, and the nucleus prepositus.