bluuebunny/crossref_metadata_2025_split huggingface dataset:
A quantitative light microscopic study of the dendrites of cat spinal α‐motoneurons after intracellular staining with horseradish peroxidase
Authors: Ulfhake B. , Kellerth J.‐O. 
Published: May 2005

AbstractThe cell bodies and dendrites of cat spinal α‐motoneurons were studied after intracellular staining with horseradish peroxidase.The mean diameter of the soma was positively correlated to both the mean diameter and the combined diameter of the first‐order dendrites, but not to the number of first‐order dendrites. On the average, 11.2 dendrites originated from the soma.The dendritic trees were more extensive than has been described previously. The mean value for the combined length of a whole dendrite was 4.7 mm, while the mean values for the total surface area and volume of a dendrite were 33.0 × 103 m̈m2 and 27.2 × 103 m̈m3, respectively. The diameter of the first‐order dendrite was positively correlated to the combined length of the entire dendrite, the number of dendritic branching points, and the number of dendritic end branches. The diameter of the first‐order dendrite was also directly proportional to the volume and the surface area of the entire dendrite. About 75% of the dendritic surface area and 55% of the dendritic volume was located more than 300 m̈m away from the soma. The dendrites constituted about 97% of the surface area and about 75% of the volume of the entire motoneuron (excluding the axon).The dendritic tapering was moderate. On the average, the distal decrease in dendritic diameters caused a reduction in the combined dendritic parameter (Σ3/2) by 1.5% and 15% at 500 m̈m and 800 m̈m distance, respectively, from the soma.
A quantitative light microscopic study of the dendrites of cat spinal γ‐motoneurons after intracellular staining with horseradish peroxidase
Authors: Ulfhake B. , Cullheim S. 
Published: May 2005

AbstractBy the use of intracellular staining with horseradish peroxidase (HRP), the dendric systems of spinal γ‐motoneurons of the adult cat were studied with a light microscope.The dendrites extended in various directions up to 1.5 mm from the cell body. The dendric branching was sparse and even unbranched dendrites were occasionally seen. The number and combined diameter of the first‐order dendrites increased in parallel with the mean cell body diamter.The number of dendric end branches, the combined dendritic length, the membrane surface area, and the volume of the entire dendrite correlated positively with the diameter of the parent first‐order dendrite.In comparison with the α‐motoneurons (Ulfhake and Kellerth, '81) the γ‐motoneurons had smaller values for mean cell body diameter and mean diameter of the first‐order dendrites and they also had a smaller number of first‐order dendrites. The dendrites of the γ‐motoneurons were also found to have fewer branching points and larger values for combined dendritic length. The relation between the diameter of the first‐order dendrite and the surface area of the entire dendrite was almost identical for the two types of motoneurons.
Ontogeny of somatostatin‐containing neuron system of the rat: Immunohistochemical observations. I. Lower brainstem
Authors: Shiosaka Sadao , Takatsuki Kenichi , Sakanaka Masahiro , Inagaki Shinobu , Takagi Hiroshi , Senba Emiko , Kawai Yuriko , Tohyama Masaya 
Published: May 2005

AbstractThe ontogeny of the somatostatin (SRIF) neuron system in the lower brainstem of the rat was analyzed using the indirect immunofluorescence technique of Coons.SRIF‐positive structures first appeared in the primordium of the ventral nucleus of the lemniscus lateralis of the rat fetus corresponding to gestational day 15 (12–14‐mm embryos). On and after gestational day 15, these structures appeared in progressively more diverse areas of the lower brainstem and continued to show an increase in number and intensity up till birth. The maximum SRIF‐positive structures were histochemically identified in the lower brainstem at the perinatal stage. However, after birth, the numbers of SRIF‐positive structures in the lower brainstem began to decrease as the rat grew and none or only a few SRIF‐positive structures were detected in the adult rats. This ontogenetical study of the SRIF neuron system in the lower brainstem of the rat strongly suggests that SRIF might play an important role in the development of the lower brainstem other than in its neurotransmitter or neuromodulator function.
The dorsal lateral geniculate nucleus of the normal ferret and its postnatal development
Authors: Linden D. Card , Guillery R. W. , Cucchiaro Josephine 
Published: May 2005

AbstractThe anterograde transport of 3H proline and of horseradish peroxidase has been used to study the retinogeniculate pathway in normal adult ferrets and in young ferrets during postnatal development. The lateral geniculate nucleus in adults shows a characteristic “carnivore” pattern, with layers A, A1, C, C1, C2, and C3, and a medial interlaminar nucleus recognizable either cytoarchitectonically or on the basis of the retinogeniculate innervation. In addition, there is a well‐defined, rather large perigeniculate nucleus.At birth the lateral geniculate nucleus is unlaminated and essentially all parts are reached by afferents from both eyes. The crossed component is by far the larger. It extends from the optic tract medially well into the perigeniculate field, in contrast to the uncrossed component which barely reaches the perigeniculate field. During the first 3 postnatal days the uncrossed fibers restrict their arbors to a small posterior and medial region, the precursor of the binocular segment of the nucleus. The crossed fibers gradually retreat from the region within which the uncrossed fibers have concentrated. Between the fourth and eighth postnatal days the field occupied by the ipsilateral component expands again to form a major focus that will define lamina A1 and a minor focus that will define C1. At this stage the crossed and the uncrossed fibers overlap at the borders of lamina A1 and the whole region of lamina C1 is also occupied by arbors of the crossed component. The perigeniculate field becomes clearly distinguishable from the lateral geniculate nucleus and the medial interlaminar nucleus is becoming clearly recognizable between days 3 and 8.Between days 8 and 15 the cytoarchitectonic borders between layers A and A1 become clearly defined, but the retinogeniculate axons from each eye still extend across this border. These axons retreat into their appropriate lamina after the 15th postnatal day and the nucleus reaches its essentially adult structure by about the fourth postnatal week. Segregation of retinofugal axons in the C layers occurs after segregation in the A layers, but many of the cells within the C layers show signs of cytological maturity earlier than those of the A layers. The nucleus undergoes a series of migrations and changes of shape as the ipsilateral and contralateral components become segregated. Whereas in the newborn the nucleus is roughly comma‐shaped and on the lateral aspect of the dorsal thalamus, in the adult it is “L”‐shaped and mainly on the posterior aspect of the dorsal thalamus.
3H‐thymidine long survival autoradiography as a method for dating the time of neuronal origin in the chick embryo: The locus coeruleus and cerebellar Purkinje cells
Authors: Yurkewicz Lorraine , Lauder Jean M. , Marchi Mario , Giacobini Ezio 
Published: May 2005

AbstractContrary to previous assumptions, we have found that a single dose of 3H‐thymidine (25 μCi), injected into the yolk sac of White Leghorn chick eggs on 2 days of incubation (d.i.) only remains available for DNA‐synthesizing (proliferating) cells for 48 hours following the time of injection. This finding now makes it possible to date the time of neuronal origin in the avian embryo using a single injection of isotope and a long survival time (30 days posthatch) as in mammalian studies where 3H‐thymidine is only available as a short “pulse.” Using this method, we have determined that neurons in the chick locus coeruleus (LC) cease proliferation on 2–6 d.i. with a peak of neuronal genesis on 3–5 d.i. In addition, neuronal genesis is not homogeneous throughout the LC cell population, but occurs in a predominantly caudorostral gradient. Conversely, the cerebellar Purkinje cells cease division on 3–8 d.i. with a peak of heavy labeling on 4–6 d.i., 1 day later than that observed in the LC.
Multiple classes of photoreceptors and neurons in the frontal organ of Rana pipiens
Authors: Eldred William D. , Nolte John 
Published: May 2005

AbstractAn attempt has been made to characterize the photoreceptors and neurons of the frontal organ of Rana pipiens and the synaptic contacts of these cells, in order to provide morphological correlates for previous physiological findings. Neurons, glial cells, and photoreceptors with two different appearances can be seen in normal anatomical preparations. The photoreceptors make ribbon synaptic contacts onto both neurons and other photoreceptors. Retrograde transport of either cobalt or horseradish peroxidase through the frontal nerve results in labeling of neurons which are often located near the exit point of the frontal nerve from the frontal organ. Some of the dendritic processes of these neurons ramify among the neurons themselves, while others ramify among the photoreceptors. In addition, the frontal organ contains two photoreceptor types which synaptically contact both neurons and other photoreceptors. In some frontal organs labeled with cobalt (but never in peroxidase‐labeled preparations) certain photoreceptors were also labeled. The labeled photoreceptors were probably the result of transcellular cobalt movement from labeled neurons, and not the result of some photoreceptors having axons in the frontal nerve. These results are discussed in conjunction with physiological evidence that chromatic interactions occur within single photoreceptors, each of which contains a single visual pigment with two physiologically active states.
Organization and development of brain stem auditory nuclei of the chicken: Dendritic development in N. Laminaris
Authors: Smith Zaid D. J. 
Published: May 2005

AbstractNucleus laminaris (NL) is a third‐order auditory nucleus in the avian brain stem which receives spatially segregated binaural inputs from the second‐order nuclei magnocellularis. The examination of the development of dendritic structure in NL revealed a number of events:In the initial period of dendritic growth (E 8–9) there is no gradient of dendritic morphology or apparent size.Starting about E 9–10, there is a spatiotemporal gradient of proliferation of numerous fine dendritic processes, from rostromedial to caudolateral, corresponding with the morphological lamination of NL, and possibly with the onset of cell death. This is followed by a spatiotemporal gradient of the elimination of the overproliferated processes, from rostromedial to caudolateral, possibly coinciding with the cessation of cell death. A result of the spatiotemporal gradients of dendritic process proliferation and elimination is a spatial gradient in the morphology (extension, branching) of the remaining “mature” dendrites.At E 15 there is only a slight spatial gradient of total dendritic size across NL; this gradient is larger at E 19, and by P 25 there is a 13‐fold change in dendritic size from rostromedial to caudolateral. Regression analyses suggest the size gradient begins to form when NL activity becomes driven by cochlear activity, at about E 14. The progressive formation of the size gradient is largely the result of two factors: the growth of dendritic trees, and the loss of primary dendrites.The growth rate of the dendritic trees of NL cells was found to be very highly correlated with the intensities of the sound frequencies to which the cells respond.From E 15 to P 25 there is a 50% loss of the “mature” primary dendrites of NL neurons.The separate dorsal and ventral dendritic size gradients seen at E 15 realign to coincide at E 19, and the moderate correlation of dorsal and ventral dendritic sizes seen at E 15 and E 19 is significantly increased at P 25, indicating a developmental process of sharpening in the relationship of the dorsal and ventral dendritic organizations in the nucleus.The data suggest that a key element in the regulation of dendritic size and structure in n. laminaris may be the activity of the afferents to the cells.
Retinal projections in the goldfish: A study using cobaltous‐lysine
Authors: Springer Alan D. , Gaffney James S. 
Published: May 2005

AbstractCobaltous lysine applied to the distal stump of a severed opticnerve was used to study the retinal projections of normal adult goldfish. Both the termination areas of optic axons and the pathways they traveled were established. Contrary to previous descriptions of the goldfish visual system, the optic nerves do not decussate completely at the optic chiasm. Fascicles that entered the ipsilateral optic tract innervated targets in the ipsilateral thalamus and optic tectum. Other optic fibers crossed the posterior commissure from the contralateral side of the brain and also innervated the ipsilateral tectum and thalamus. In addition, optic fibers bilaterally innervated a hypothalamic target in close proximity to the infundibulum that may correspond to the nucleus tuberis lateralis. The contralateral preoptic region contained two discrete areas of innervation, each served by separate fascicles. The ipsilateral preoptic region was similarly innervated, but more sparsely. Fibers that entered the contralateral ventral thalamus originated from three fascicles and terminated in three distinct targets. In contrast, three targets in the contralateral dorsal thalamus were served by one fascicle, and fibers passed from one nucleus to the other two. Innervation of the ipsilateral thalamus was similar to that seen contralaterally. Each main optic tract divided into three tracts, two of which entered the optic tectum, while the other innervated several pretectal areas. Other fibers innervated an accessory optic nucleus located near nucleus glomerulosus. The contralateral tectum contained numerous radially oriented optic fascicles. These fascicles represented optic fibers that left thalamic and pretectal targets to enter the optic tectum from beneath the stratum periventriculare. Optic fibers were also observed in the transverse commissure, tractus rotundus, horizontal commissure, tractus rotundus, horizontal commissure, tectobulbar tract, and fasciculus retroflexus. Therefore, it appears that many of the anomalous projections seen after tectal ablation or after optic nerve crush are not in fact aberrant. Such projections probably reflect the presence of unusually large numbers of optic fibers in tracts that normally contain optic axons, as well as increased innervation of areas that normally receive sparse retinal projections. Filled tectal cells that could represent cells projecting to the retina were not observed in either tectal lobe. The ipsilateral retinal projections could not be attributed to cobaltouslysine being transneuronally transported in readily detectable amounts.
Aging in the rat olfactory system: Correlation of changes in the olfactory epithelium and olfactory bulb
Authors: Hinds James W. , McNelly Nancy A. 
Published: May 2005

AbstractTwo regions closely linked synaptically (olfactory epithelium and olfactory bulb) have been compared in an agegraded series of rats. Previous findings of growth and atrophy of constituent elements in Sprague‐Dawley Wisconsin (SD) rats have now been confirmed in Charles River (Crl) rats. In the olfactory bulbs of Charles River (Crl) rats, the volume of layers, the number of olfactory axodendritic synapses in the glomeruli, the total volume of glomerular dendrites, and the size of mitral cell bodies all approximately double between 3 and 24–27 months, and then all decrease by 36 months. Unlike SD rats, however, no loss in the number of mitral cells occurs in Crl rats, and the increase in volume of the olfactory bulbs from 3 to 24 months is approximately double that of SD rats. In the olfactory epithelium the total number of septal olfactory receptors more than doubles between 3 and 18–24 months and then declines markedly, as does the volume of olfactory axons in olfactory bulb glomeruli. Comparison of the regression lines for changes in number of septal receptors with that of the size of mitral cell bodies discloses that the decline in number of receptors begins several months earlier than the decline in mitral cell size. This suggests that the atrophic changes in the olfactory bulb may in part be secondary to changes in the receptors of the olfactory epithelium. Numbers of synapses in the glomeruli appear to decline less markedly with age than the number of receptors, and a significant increase in number of synapses per receptor occurs in the oldest group studied (33 months), suggesting a compensatory increase in the relative number of synapses per receptor in the surviving receptors.
Structural patterns in the corpora pedunculata of orthoptera: A reduced silver analysis
Authors: Weiss Mitchell J. 
Published: May 2005

AbstractThe calyx region and pedunculus of the corpora pedunculata (“mushroom bodies”) were studied comparatively in reduced silver preparations of the brain from 16 species of Orthoptera representing four families (Acrididae, Gryllidae, Tettigoniidae, and Gryllacrididae). In the acridid grasshopper Melanoplus femurrubrum (de Geer), on which emphasis was placed, the concave primary calyx is bilayered and exhibits a special central zone. Globuli cell axons occur within both layers. The bulbous accessory calyx is unlayered and sends anterior extensions beneath the primary calyx. The main input tracts into primary and accessory calyx, respectively, are the tractus olfactorio‐globularis and tritocerebral tract. The pedunculus consists of one barrel with three major fiber columns, of which two originate in the primary calyx and one in the accessory calyx. Its fibers display a coaxial arrangement, superimposed on the tripartite organization. Structural conditions in other acridids are similar.In the other families the calyx region similarly includes a bilayered primary calyx and unlayered accessory calyx. The latter, variable in form, is closely associated with the base of the primary calyx in tettigoniids and gryllacridids. The calyces receive the same major tracts as in acridids. The pedunculus is coaxially organized.These features are theorized to have originated as follows. In the progenitors of Orthoptera the corpora pedunculata included two mutually equivalent, bilayered calyces and a “double‐barreled” pedunculus. The orthopteran primary calyx arose through coalescence of these calyces. Concomitantly, the two peduncular barrels fused into one. The accessory calyx originated at the base of the primary calyx, from the class of globuli cell axons of the latter's external layer. Probably this occurred in response to increased functional importance of tritocerebral input.
Monoamine cell distribution in the cat brain stem. A fluorescence histochemical study with quantification of indolaminergic and locus coeruleus cell groups
Authors: Wiklund Leif , Léager Lucienne , Persson Mats 
Published: May 2005

AbstractThe distribution of monoaminergic cell bodies in the brainstem of the cat has been examined with Falck‐Hillarp fluorescence histochemical technique. Quantitative determinations indicate that the cat brainstem contains about 60,300 indolaminergic (IA) cells. The majority of these (about 46,700, or 77.5%) are located within raphe nuclei. The largest number is contained within nucleus raphe dorsalis (RD), accounting for around 24,300 IA cells, while raphe pallidus (RP) holds about 8,000, raphe centralis superior (RCS) 7,400, raphe magnus (RM) 2,400, raphe obscurus (RO) 2,300, linearis intermedius (LI) 2,100, and the raphe pontis (RPo) only some 280 IA cells. The IA cells represent, however, only part of the neuronal population of raphe nuclei, which, in addition, hold varying numbers of other medium‐sized and small‐sized neurons. Thus, quantifications in Nissl‐stained material indicate that the IA cells make up about 70% of the medium‐sized cells in RD, 50% in RP, 35% in RCS and RO, 25% in LI, 15% in RM, and only 10% in RPo. The substantial numbers of small‐sized perikarya observed in all raphe nuclei may represent interneurons.Significant numbers of IA cells were consistently located outside the raphe nuclei at all brainstem levels. In all, these amounted to approximately 13,600, or 22.5% of the total number of IA cells. Thus, IA cells occurred in the myelinated bundles, and sometimes in reticular formation, bordering the raphe nuclei; in the ventral brainstem forming a lateral extension from the ventral raphe (RP, RM, RPo, RCS, and LI) to the position of the rubrospinal bundle; in the periventricular gray and subjacent tegmentum of dorsal pons and caudal mesencephalon; in the locus coeruleus (LC) complex; around the motor trigeminal nucleus; caudal to the red nucleus; and in the interpeduncular and interfascicular nuclei. The wide distribution of IA cells leads to a considerable mixing with catecholaminergic (CA) cell groups.Our observations on CA cell distribution are essentially in accordance with previous reports. Quantifications indicate that the LC complex contains about 9,150 CA cells, unilaterally. A previously unnoticed group of scattered CA cells was found in relation to the vestibular nuclei and extending dorsally toward the deep cerebellar nuclei.
Plasticity in the chick ventral lateral geniculate nucleus
Authors: Crossland W. J. 
Published: May 2005

AbstractThe chick ventral lateral geniculate nucleus (GLv) receives topographically corresponding projections from the retina and optic tectum. Tectal lesions produced on the day of hatching removed the tectogeniculate input to the GLv region corresponding to the tectal lesion and also severed some retinotectal axons. Following a survival period of 3 to 10 weeks, a patch of augmented retinogeniculate projection was noted in the GLv segment that corresponds topographically to the damaged area of the tectum. Changing the site of the tectal lesion led to changes in the locus of heavy retinal projection to the GLv predictable from topographic maps. Nuclei which received retinal but not tectal projections did not appear to have regions of augmented retinal termination nor did nuclei which received tectal but not retinal innervation. It is unlikely that the increased retinogeniculate termination is due to rerouting of growing retinotectal axons since the chick retinofugal pathway is well established by the time of hatching. Furthermore, there was no evidence of a projection from the ipsilateral eye to the affected GLv. On the basis of these light microscopic studies, it would appear that retinogeniculate terminals have sprouted in the GLv and that competition for terminal space, conservation of terminal space, proximity, and perhaps other factors are necessary for the augmented projection to occur.