bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impulses in dorsal spinal nerve rootlets in cats and rabbits arising from dorsal root ganglia isolated from the periphery
Authors: Kirk E. J. 
Published: January 2005

AbstractSpontaneous discharges arising within lumbar dorsal root ganglia that had been isolated from the periphery by section of the corresponding spinal nerves were recorded in dorsal spinal nerve rootlets in cats and rabbits. Those dorsal rootlet fibers that were individually isolated had conduction velocities of less than 22 meters/second, i.e., they were Aδ fibers. The chronic preparations had been kept alive for between 1 and 21 days, and spontaneous activity was present in each of them. In acute preparations in which hemorrhage was minimal, spontaneous activity first appeared three to three and one‐half hours after section of the spinal nerve. Spontaneous activity in the dorsal rootlets continued for approximately 25 minutes after physical separation, by dissection, of the active nervous tissue from the remainder of the preparation. The activity was not recorded in either the distal parts of sectioned ventral rootlets or the portion of a sectioned spinal nerve that remained in continuity with its dorsal root ganglion.It is suggested that the occurrence of these discharges could partly explain the observed differences in the extent and reactivity of cutaneous sensory areas between animals in which dorsal spinal nerve rootlets were sectioned close to the spinal cord and animals in which the corresponding spinal nerves were sectioned distal to their dorsal root ganglia.
The neuronal architecture of the cochlear nucleus of the cat
Authors: Brawer James R. , Morest D. Kent , Kane Eileen Cohen 
Published: January 2005

AbstractA detailed parcellation of the entire cochlear nucleus of the cat was prepared with the Nissl and Protargol methods in the form of a cytoarchitectonic atlas. Neuronal cell types were characterized in rapid Golgi impregnations. Golgi impregnations were used to define the specific features of the mature neuronal types. Neurons from the Golgi preparations were systematically mapped according to type and location in serial sections. These neurons were then plotted in corresponding positions in the cytoarchitectonic atlas. This combined Golgi‐Nissl approach provides a scheme in which neuronal types, defined in terms of a number of functionally significant features, can be precisely localized within the cochlear nucleus.
The naso‐temporal division of the cat's retina re‐examined in terms of Y‐, X‐ and W‐cells
Authors: Stone Jonathan , Fukuda Yutaka 
Published: January 2005

AbstractIn the cat, as in all mammals, optic nerve fibres decussate only partially, so that some of the ganglion cells in one retina project to the contralateral side of the brain, and some to the ipsilateral side. The retinal distribution of ipsi‐ and contralaterally projecting ganglion cells, described in a previous study, has been re‐examined in the context of the recent classification of cat retinal ganglion cells into three major types (W‐, X‐ and Y‐cells). Evidence is presented of significant differences between the three cell types in the retinal distribution of ipsi‐ and contralaterally projecting cells. The pattern of naso‐temporal division of retina described previously thus appears to be a composite of the different patterns of the three cell types. Functional implications of these different patterns are considered.
Projections from the striate cortex to the diencephalon in the squirrel monkey (Saimiri sciureus). A light microscopic radioautographic study following intracortical injection of H3 leucine
Authors: Holländer Horstmar 
Published: January 2005

AbstractTritiated leucine was injected into three different regions of the striate cortex in nine squirrel monkeys and the axoplasmic transport of labelled protein in the neurons was used to identify terminal fields of projection in the thalamus. The regions of injection corresponded to those representing about 3°, 10°, and 30° eccentricity in the contralateral visual field. The periods of post‐injection survival were 9–19 hours, 8 days, and 23 days. The exposure was about three weeks in all cases. In the thalamus terminal fields of projection were identified in the lateral geniculate nucleus, the posterior nucleus of the thalamus, the inferior and lateral pulvinar nucleus, the reticular nucleus of the thalamus and the pregeniculate nucleus. In most of the projections the location of the terminal fields varied systematically with the location of the injection site indicating a retinotopic organization. In eight of the nine experiments all of the thalamic projections were observed. In the cases with postinjection survival times of 8 and 23 days pronounced axonal labelling was seen, and the corticothalamic pathway could be traced from the site of injection to the thalamus. In one experiment in which only the superficial layers of the cortex were labelled by the injection no thalamic projection was found.
Photoreceptor degeneration and synaptogenesis in retinal‐degenerative (rd) mice
Authors: Blanks Janet C. , Adinolfi Anthony M. , Lolley Richard N. 
Published: January 2005

AbstractThe influence of photoreceptor degeneration upon synaptogenesis in the photoreceptor terminal of developing retinae of rd mice (C3H/HeJ and C57BL rd le) is outlined and compared to the sequential development of the photoreceptor terminals of the retinae of normal mice. The initial phases of synaptogenesis in the photoreceptor terminal of the rd retina appear normal during the first postnatal week. Appositional contacts form between the photoreceptor terminal and neuronal processes before invagination of horizontal processes occurs to form a dyad configuration. A virtual absence of triad configurations in the photoreceptor terminal suggests that synaptogenesis is arrested in the photoreceptor terminal of the rd retina between the 7th and 10th day, at which time the central (bipolar) process normally invaginates into the photoreceptor terminal. During this period, photoreceptor cell death proceeds rapidly but few signs of degeneration are apparent. It is suggested that the inherited abnormality influences the maturation of bipolar cells more than that of horizontal cells. The b‐wave component of the electroretinogram (ERG) of the immature rd retina is discussed in terms of photoreceptor/bipolar cell synaptic contacts.
Quantitative studies on motoneurons. II. Spatial and dimensional organization of hypoglossal motoneurons in the boa constrictor, Constrictor constrictor
Authors: Ulinski Philip S. 
Published: January 2005

AbstractThe spatial distribution and sizes of degenerating hypoglossal neurons were studied following the removal of the genioglossus or hyoglossus muscles or of unilateral glossectomy in common boas with survival times of 7, 14, 21 or 40 days. The spatial organization of this nucleus differs from that of most cranial nerve nuclei in lacking a subnuclear organization: genioglossus and hyoglossus motoneurons are spread evenly throughout the nucleus and intrinsic tongue neurons show only a slight tendency to accumulate in the caudal half of the nucleus. The genioglossus and tongue neurons probably serve both ipsilateral and contralateral muscles with the ipsilateral innervation being largest; the hyoglossus motoneurons probably innervate only ipsilateral muscles. Complementary analyses of the transverse sectional areas of both degenerating and non‐degenerating neurons indicates that, although their size ranges overlap, genioglossus motoneurons are small and tongue and hyoglossus motoneurons are progressively larger.
Topographic atlas of catecholamine and acetylcholinesterase‐containing neurons in the rat brain. II. Hindbrain (mesencephalon, rhombencephalon)
Authors: Palkovits Miklos , Jacobowitz David M. 
Published: January 2005

AbstractA complete stereotaxic neuroanatomical atlas of the rat hindbrain was prepared using transverse serial sections stained with Luxol fast blue and cresyl violet. Catecholamine‐containing cell bodies and fiber terminals were identified by the histofluorescence method. The acetylcholinesterase distribution was histochemically localized. A detailed stereotaxic atlas of the catecholaminergic and acetylcholinesterase‐containing structures is presented.
Formation and regression of inappropriate nerve sprouts ing trochlear nerve regeneration in Xenopus laevis
Authors: Fangboner Raymond F. , Vanable Joseph W. 
Published: January 2005

AbstractAfter sectioning N IV in Xenopus laevis larvae, in addition to the regeneration of that never to the superior oblique muscle (SOM), sprouts form from N III, chiefly from the branch supplying the inferior oblique muscle (IOM). these were shown to innervate the SOM by methylene blue staining, silver and zinc iodide‐osmium impregnations, and electrical stimulation of N III. The competition thus established is resolved in favor of N IV, in a way suggesting a displacement of the inappropriate sprouts by the returning N IV fibers. This hypothesis received support by two anatomical findings: a delay in the decline of N III sprouts on the SOM when the return of N IV is delayed and a significant inverse relationship between the number of N III sprouts and regenerated N IV fibers on the SOM 39 days after N IV sectioning. Degenerating N III sprouts were detected while their number was declining. The physiological studies showed a significant reduction in the function of N III sprouts tested 30–34 days after N IV sectioning as compared with larvae tested 11–15 days after sectioning, which correlated with the anatomical observations We conclude that there is a withdrawal of inappropriate nerve fibers during the resolution of competition between the regenerating N IV fibers and these sprouts from N III.
Histochemistry of cholinesterase in amphioxus (Branchiostoma lanceolatum, pallas)
Authors: Flood Per R. 
Published: January 2005

AbstractBiochemical and histochemical experiments showed that the cholinesterase activity in amphioxus is due to specific acetylcholinesterase. Light and electron microscopic histochemical staining methods demonstrated that the acetylcholinesterase activity is localized to the junctions between processes of the trunk muscle fibres and the lateral surface of the spinal cord (the central motor end plate) to the junction between processes of the muscular notochordal lamellae and the ventral surface of the spinal cord (the neuro‐chordal junction) and to the junctions between the peterygal axon plexus and processes of the pterygealmuscle fibres. In the central motor end plate the dorsal and the ventral compartments, innervating superficial “red” and deep “white” trunk muscle fibres respectively, were equally intensely stained. Lower activities were seen in the spinal cord, trunk muscle. pterygeal muscle and notochord. It is concluded that most of the specific acetylcholinesterase found in amphioxus tissues is related to various kinds of neuro‐muscular junction and accordingly that these probably are cholinergic.
Anatomical analysis of pupillary reflex pathways in the rhesus monkey
Authors: Pierson Roberta J. , Carpenter Malcolm B. 
Published: January 2005

AbstractThe pupillary light reflex was analyzed by producing lesions in afferent and efferent pathways in a series of monkeys. Unilateral enucleation and autoradiographic technics utilizing axoplasmic flow were used to determine afferent pathways. Lesions also were made in the pregeniculate nucleus (PGN) and individual components of the oculomotor visceral nuclei. Degeneration was studied in Wiitanen and Nissl stained sections. Infrared pupillographic records were made before and after surgery. Enucleation and autoradiographic studies revealed: (1) bilateral retinal projections to the pretectal olivary nuclei (PON) and PGN, and (2) predominautly contralateral projections to parts of the optic tract and sublentiform nuclei. PGN appeared to project to the ipsilateral PON. Unilateral lesions in the anterior median nucleus (AM) with direct, or indirect, involvement of the medial visceral cell column (MVCC) produced: (1) “static” and “dynamic contraction” anisocoria and (2) ipsilateral reductions in direct and consensual pupillary responses. Lesions in the rostral MVCC with no involvement of AM produced only static anisocoria. Degeneration from these lesions was found rostrally in the ipsilateral oculomotor roots, but no retrograde cell changes were detected in the pretectal region. Lesions in the caudal MVCC, the lateral visceral cell column (LVCC) and PGN produced no anisocoria or reductions in the pupillary light reflex. Both anterograde and retrograde degeneration in the contralateral PON were observed with lesions in LVCC, but no degeneration was seen in the oculomotor root fibers.
Monoamine distribution in primate brain. I. Catecholamine‐containing perikarya in the brain stem of Macaca speciosa
Authors: Garver David L. , Sladek John R. 
Published: January 2005

AbstractThe distribution of catecholamine‐containing cell bodies was examined in the brain of Macaca speciosa using the Falck‐Hillarp histofluorescence technique. Extensive accumulations of such cells were seen in the ventral tegmental area, locus coeruleus, mesencephalic reticular formation and ventrolateral reticular formation of pons and medulla. This distribution was compared to that previously reported in rat, cat, squirrel monkey and human brain. Apparent species dissimilarities and similarities are reported.
Fine structure and distribution of axon terminals from cochlear nucleus on neurons in the medial superior olivary nucleus of the cat
Authors: Lindsey Bruce G. 
Published: January 2005

AbstractThe morphology and distribution of axon terminals on central column and marginal neurons of the cat medial superior olivary nucleus (MSO) were analyzed by electron microscopy. Individual neurons or groups of cells oriented such that substantial lengths of their dendrites were within a 5–7 μthick section were selected for detailed study. Thin sections were cut from remounted thick sections. Boutons with spherical vesicles arise directly from myelinated axons; more than one synaptic region of an axon, each separated by a myelinated segment, may contact a given dendrite. Boutons with flattened and occasionally dense core vesicles arise from both myelinated and unmyelinated portions of axons; these axons may also have more than one synaptic region. Both dinds of synaptic profiles are found on the somata and dendrits of all MSO neurons.To determine which nerve endings are from the cochlear nucleus (CN) lesions were made to produce othograde degeneration. Following unilateral CN lesion degenerating spherical vesicle terminals were observed on the lateral dendrites and somata of ipsilateral central column cells and the medial dendrites and somata of contralateral neurons. Degenerating terminals were rarely seen on the opposite dendrite (three of 48 cells). In six of seven instances where medial and lateral dendrites of two cells overlapped degeneration was limited to the one oriented toward the lesion. Marginal cells examined received virtually all spherical vesicle terminals from only one CN. Terminals with flattened vesicles persisted on the somata and dendrites of all neurons studied including cells from cats with bilateral lesions.
Electron microscopical reconstruction of the anterior sensory anatomy of the nematode caenorhabditis elegans
Authors: Ward Samuel , Thomson Nichol , White John G. , Brenner Sydney 
Published: January 2005

AbstractThe complete structure of the anterior sensory nervous system of the small nematode C. elegans has been determined by reconstruction from serial section electronmicrographs. There are 58 neurons in the tip of the head. Fifty‐two of these are arranged in sensilla. These include six inner labial sensilla, six outer labial sensilla, four cephalic sensilla and two amphids. Each sensillum consists of ciliated sensory neurons ending in a channel enclosed by two nonneuronal cells, the sheath and socket cells. The amphidial channel opens to the outside as does that of the inner labial sensilla so that these probably contain chemoreceptive neurons. The endings of the other sensilla are embedded in the cuticle and may be mechanoreceptive. The cell bodies of all the neurons lie near the nerve ring and their axons project into the ring or into ventral ganglia. One of the ciliated sensory neurons in each of the six inner labial sensilla makes direct chemical synapses onto a muscle making these sensory‐motor neurons. The anatomy of four isogenic animals was compared in detail and found to be largely invariant. The anatomy of juveniles is nearly identical to that of the adult, but males have four additional neuron processes.
Ascending afferents to the telencephalon of ranid frogs: An anterograde degeneration study
Authors: Kicliter Earl , Northcutt R. Glenn 
Published: January 2005

AbstractSources of telencephalic afferents were examined in two species of frogs, Rana catesbeiana and Rana pipiens, by study of anterograde degeneration resulting from hemisection of the brain at the isthmus or at the caudal border of the thalamus and from electrolytic lesions in various portions of the diencephalon. The results indicate that some telencephalic afferents arise from levels caudal to the isthmus, that some striatal afferents arise from the level between the isthmus and the caudal border of the thalamus, and that a projection to the ipsilateral striatum arises from the anterior and/or middle portions of the dorsal thalamus. Diencephalic projections to pallial portions of the hemisphere were also observed. These results demonstrate substantial non‐olfactory afferent projections to the telencephalon in ranid frogs.
Autoradiographic studies of the projections of the midbrain reticular formation: Descending projections of nucleus cuneiformis
Authors: Edwards Stephen B. 
Published: January 2005

AbstractThe descending projections of nucleus cuneiformis in the cat were traced by autoradiography in the transverse and sagittal planes following stereotaxically placed injections of 3H‐leucine. Many descending axons are organized into distinct fiber systems, of which the largest and most well‐defined crosses directly in the midbrain and descends through the ventromedial tegmentum of the brain stem. This fiber system first terminates profusely in n. reticularis tegmenti pontis and then proceeds through the rhombencephalic tegmentum emitting transversely oriented branches to n. reticularis pontis caudalis and gigantocellularis, the raphe magnus and the facial nucleus. Its most caudal field of termination is a restricted portion of the medial accessory olive. Because of its size, compactness, and ventromedial course, this fiber system was termed the ventral tegmental bundle. In contrast, fibers descending on the ipsilateral side are more loosely organized and describe many divergent paths. In their initial course they remain in a dorsolateral position and distribute to the n. locus coeruleus, n. raphe dorsalis, the central gray matter, and n. reticularis pontis oralis. At successively more caudal levels they converge ventromedially and descend through the rhombencephalic tegmentum in a position similar to that of the ventral tegmental bundle. At the level of the facial nucleus a group of fibers splits off to form a separate fiber bundle which descends lateral to the inferior olive and distributes to the lateral reticular nucleus. No evidence was found of projections to the spinal cord or cerebellum. A portion of the tegmentum ventromedial to nucleus cuneiformis was found to project bilaterally to the facial nucleus and to the ipsilateral medial accessory olive. The results of this study are discussed in relation to the role of the midbrain reticular formation in the elaboration of certain forms of behavior.
The dorsal column nuclear projections to the nucleus ventralis posterior lateralis thalami and the inferior olive in the cat: An autoradiographic study
Authors: Groenewegen H. J. , Boesten A. J. P. , Voogd J. 
Published: January 2005

AbstractThis autoradiographic study demonstrates a topical projection of the dorsal column nuclei to the contralateral nucleus ventralis posterior lateralis thalami and the accessory part of the inferior olive. In contrast to earlier anatomical studies the projections of the gracile nucleus and the internal cuneate nucleus proved to be independent and entirely contralateral.Fibers from the gracile nucleus terminate only in the lateral part of the nucleus ventralis posterior lateralis (VPL1) and from the internal cuneate nucleus only in the medial part of this nucleus (VPLm). Projections of the gracile nucleus to the contralateral inferior olive are restricted to the caudal one‐third of the medial accessory olive and the ventrolateral part of the dorsal accessory olive. The internal cuneate nucleus is only connected with the dorsomedial part of the rostral two‐thirds of the dorsal accessory olive.Our material does not allow conclusions about projections from the dorsal column nuclei to other thalamic nuclei and about rostrocaudal point to point relationships between the dorsal column nuclei and the thalamus or the inferior olive.
Species differences in mechanosensory projections from the mouth to the ventrobasal thalamus
Authors: Bombardieri Rocco A. , Johnson John Irwin , Campos Gilberto B. 
Published: January 2005

AbstractTo determine whether the largely ipsilateral, inverted representation of mouth parts in the ventrobasal thalamus of sheep was unique to that species or an expansion of a general mammalian pattern, the corresponding thalamic projections were mapped electrophysiologically in a selected series of mammals (opossums, agoutis, squirrel monkeys, cats, raccoons, and sheep) representing major branches of evolution among therian mammals. In mapping, tungsten microelectrodes were used to record multi‐unit discharges in the thalamus in response to mechanical stimulation of oral surfaces. The pattern of projections seen in sheep is not a general mammalian pattern; there is extensive variability among mammals in the laterality and internal organization of the projections from the mouth. In spite of the great variability, the results suggest an hypothesis concerning phylogenetic trends: descendants of palaeoryctoid insectivores (cats, raccoons, and sheep in our sample) have extensive ipsilateral projections from the mouth, in other therian mammals (opossums, agoutis, and squirrel monkeys in our sample) the ipsilateral component is small or absent.