bluuebunny/crossref_metadata_2025_split huggingface dataset:
Number and distribution of the apical dendritic spines of the layer V pyramidal cells in man
Authors: Marin‐Padilla Miguel 
Published: January 2005

AbstractThe number and the distribution of the apical dendritic spines was investigated in the layer V pyramidal cells of the human cerebral cortex. This study was carried out in the motor cortices of an 8‐month fetus, a premature infant, and a newborn, 15‐, 19‐ and 45‐day‐old infants; in the somesthetic cortex of a newborn infant; and in the auditory cortex of a newborn infant. This study has shown: (a) that the number of spines increases with the age, (b) that the spines are distributed along the apical dendrites in a characteristic manner which, graphically represented, consists of a curve with three distinct deflexions, (c) that the spine‐distribution along the apical dendrites of the layer V pyramidal cells is similar in all cases studied regardless of their age or their cortical location (motor, somesthetic and auditory cortices), (d) that the distribution of the spines along the apical dendrites appears to depend on the nature of the dendrite, (e) that the sequence of the mean number of spines maintains an exponential relationship with the distance from the cell body for the first and second deflexions of the spine‐distribution curves. The significance of the distribution of the spines along the apical dendrites of the layer V pyramidal cells is discussed. A new method is presented and its possible application to the study of the normal development and pathoIogical conditions of the cerebra1 cortex is suggested.
The hyperstriatal region of the avian forebrain: A lesion study of possible functions, including its role in cardiac and respiratory conditioning
Authors: Cohen David H. 
Published: January 2005

AbstractThe behavior of 12 pigeons with hyperstriatal lesions (10 bilateral and 2 unilateral) was compared with that of 13 control birds. Neurological examination indicated no striking postural deficits, and all reflexes investigated were normal. However, lesions did reduce escape behavior, spontaneous flight, and responsiveness to exteroceptive stimuli. Avariety of vegetative functions including body temperature, food and water intake, and cardiac and respiratory rate were unaffected.Defensive conditioning, differentiation and extinction performance were also assessed. Birds with lesions showed no impairment of cardiac conditioning, but respiratory conditioning was slower than in control animals. Both cardiac and respiratory differentiation were weak, respiratory differentiation being more severely affected than cardiac differentiation. Neither group of birds showed extinction.Evidence for hpyerstriatal participation in visual function is reivewed, and it is proposed that an important role of the hyperstriatum is mediation of certain somatic responses to visual stimuli and that deficits following ablation may be secondary to impairment of visual orienting responses.
Marsupial interhemispheric relation
Authors: Putnam Serpas J. , Megirian David , Manning John W. 
Published: January 2005

AbstractThree different responses recorded from the opossum neocortex following a stimulus to the homotopical point on the contralateral hemisphere were: the interhemispheric early response (IER), the interhemispheric delayed response (IDR), and the rhythmic afterdischarge (RA). The IER was a short latency biphasic slow wave evoked potential which could be recorded from every homotopic point on the neopallium with the exception of a part of the striate cortex. Each active homotopic point had a limited heterotopic halo. The homotopic positive peak latency varied from 5.3 msec in the area parietalis to 14.7 msec in the area striata. Interhemispheric transfer was effected via the anterior commissure. The IDR was a late slow wave evoked potential and had an extensive heterotopic representation. This potential could be recorded in the contralateral hemisphere after sectioning the anterior commissure. The homotopic positive peak latency varied from 60.2 msec in the area parietalis to 76.1 msec in area striata. To abolish the IDR both the di‐mesencephalic junction and the interthalamic commissure had to be sectioned. The RA is a very labile late oscillatory potential which was very difficult to demonstrate without a computer of average transients. The pattern of its homotopic and heterotopic representation resembled very closely that of the IER. Under the conditions of our experiment it had a negative peak latency of 224–230 msec, a frequency of oscillation of three seconds and a maximum duration of 2.2 seconds. To abolish the RA both the di‐mesencephalic junction and the interthalamic commissure had to be sectioned. The dorsal commissure contained no neopallial intorhemispheric fibers. The anterior commissure carried these commissural connections. The two late responses reported in the opossum fell within the general context of mammalian late responses.
Developmental changes of the endoplasmic reticulum and ribosomes in nerve cells of the spinal ganglia of the domestic fowl,
Authors: Pannese Ennio 
Published: January 2005

AbstractThe changes of the endoplasmic reticulum (ER) and ribosomes in developing nerve cells of the spinal ganglia of the domestic fowl have been studied by light and electron microscopy.The thin rim of cytoplasm encircling the nucleus of the undifferentiated cells contains numerous free ribosomal clusters and a scanty endoplasmic reticulum.The primitive neuroblasts are spindle‐shaped and their two processes contain filamentous structures. In comparison with the undifferentiated cells, primitive neuroblasts have many more free ribosomes and a prominent rough‐surfaced ER consisting of long, interconnected channels often continuous with the nuclear envelope. The remarkable development of the ER is one of the main characteristics of differentiating ganglionic nerve cells. Subsurface cisternae become apparent first in the primitive neuroblasts.The ER and ribosomes of the intermediate neuroblast are confined in the peripheral region of the perikaryon; mitochondria, Golgi complexes, dense bodies, microtubules, neurofilaments, etc. are located more centrally. Units of the smooth‐surfaced ER appear first in the intermediate neuroblasts.In the pseudo‐unipolar nerve cells, the cisternae of the ER and the ribosomes are mainly grouped in discrete areas (Nissl bodies). The rough‐surfaced ER is more developed and highly organized in the intermediate neuroblasts and especially in the pseudo‐unipolar nerve cells than in the primitive neuroblasts. In the pseudo‐unipolar nerve cells, peculiar relationships between ER and Golgi complexes have been observed.Both free and membrane‐attached ribosomes are arranged in clusters (polysomes) in all the developmental stages of the ganglionic nerve cells. The highest number of ribosomes in the membrane‐attached polysomes is at least 13.The electron microscopic images suggest that the ER of the developing neuroblasts might take its origin from the nuclear envelope and afterwards might increase in volume through an intrinsic expansive growth of its membranes.
A secretory role for the lipid bodies of molluscan neurons
Authors: Benjamin P. R. , Peat A. 
Published: January 2005

AbstractThe lipid bodies of neurons from the osphradia ganglion of the freshwater Snail Planorbarius corneus have been examined with the electron microscope. These lipid bodies show a variety of structural forms which have been interpreted as a cycle. Early stages consist of a single‐membraned sac enclosing cytoplasm similar in appearance to that of the general neuronal cytoplasm. Complicated systems of membrane lamellae and filaments develop with the membranes often being associated with oval areas of structureless material. The later stages of the cycle are dominated by this material. It seems probable that the structureless material is secreted by the membranes. The lipid bodies show a breakdown sequence when their contents pass into the neuronal cytoplasm. Remnant lipid bodies have been found which contain only fragments of membrane and a small number of filaments, with small areas of residual structureless material. A possible neurosecretory role is considered.
An electron microscopic study of the neuroglia during postnatal development of the rat cerebrum
Authors: Caley David W. , Maxwell David S. 
Published: January 2005

AbstractThe differentiation of spongioblasts from undifferentiated cells and into neuroglial cells has been studied in the postnatal rat cerebral cortex with the electron microscope. The nuclei of all the non‐neural elements are characterized by clumping of dense chromatin, especially near the nuclear envelope. The undifferentiated cells possess only a thin rim of perinuclear cytoplasm containing few organelles. Spongioblasts are characterized by an increased number of cytoplasmic organelles, mostly mitochondria and Golgi complex, and by the growth of processes. These cells mature and take on either the features of oligodendrocytes or astrocytes. The multiple oligodendrocyte processes are thin and branching and develop intimate contacts with the developing axons. Early stages of myelination are characterized by the envelopment of axons by oligodendrocyte processes which overlap each other to form inner and outer tongues that are cheracteristic of central nervous system myelin. Astrocytes can be distinguished by the presence of cytoplasmic glycogen particles and fibrils. Processes of these latter cells develop intimate relations with the developing blood vessels. A variety of cell was occasionally encountered which is termed the polycystic cell. This cell may be quite large, contains numerous cysts and vesicles of various types and appears to be a form of spongioblast. No cells which would qualify as “microglia” were observed.
The aorticorenal ganglion and its role in renal innervation
Authors: Norvell John E. 
Published: January 2005

AbstractA detailed dissection of the renal plexus and the aorticorenal area was carried out in 57 adult cadavers (32 males and 25 females). This study showed that the aorticorenal ganglia may be located anywhere in the general area of the junction of the renal arteries with the aorta. These ganglia were found to be partly fused with the celiac ganglion in 4% on the right side and in 12% on the left. All three thoracic splanchnic nerves (greater, lesser, and least) may have rami which terminate in the aorticorenal ganglia. The least splanchnic terminated in the aorticorenal ganglion more often than the other nerves when the ganglion was located inferior to the renal artery. In this location, the first lumbar splanchnic nerve also may terminate in the aorticorenal ganglion. The aorticorenal ganglia also had connections with the renal plexus, inermesenteric nerves, celiac and superior mesenteric plexuses, adrenal gland, and possibly with the spermatic and ovarian plexuses through the renal plexus.By using the silver impregnation technique of Holmes, we found the aorticorenal ganglia to have a role in renal innervation. When these ganglia were unilaterally removed from a series of 14 cats, a definite reduction of nerve fibers associated with the tubules of the renal cortex, and to lesser extent, with the renal blood vessels, was observed. Most nerve endings were associated with the proximal convoluted tubules, but a few were observed in the glomeruli.
Golgi study of the nucleus of the transpeduncular tract in the rabbit
Authors: Giolli Roland A. , Braithwaite J. Ronald , Streeter Thomas T. 
Published: January 2005

AbstractThe nucleus of the transpeduncular tract was studied in Golgi, reduced silver, and Nissl series of the brain stems of newborn and adult albino rabbits. The nucleus contains cells which differ with respect to their dendritic orientation, dendritic pattern, and size. The terms intranuclear and extranuclear are further used to designate those cells respectively whose axons are restricted to the nucleus or are projected outside the nucleus. The intranuclear cells usually lie ventrally, and their axons distribute dorsally, within the nucleus; and on this basis, the nucleus is divisible into ventral and dorsal divisions. The axons of some of the extranuclear cells studied project and terminate within the substantia nigra, midbrain reticular formation, or red nucleus; whereas the axons of others pass into the transpeduncular tract or medial lemniscus.This study reveals that individual axons of the transpeduncular tract terminate in ventral or dorsal nuclear divisions and suggests that the transpeduncular tract input comprises the largest projection to the nucleus. Axons of cells of the substantia nigra, as well as axons passing from the midbrain reticular formation and probably the anterior accessory optic tract, are shown to terminate primarily within the dorsal division of the nucleus. Axons from the cerebral peduncle are found to end mainly within the ventral division of the nucleus. The findings are discussed in relation to existing biological data.
Calibre spectra of the lingual and hypoglossal nerves of the rhesus monkey
Authors: Egel Robert T. , Bowman James P. , Combs C. Murphy 
Published: January 2005

AbstractThe presence of muscle spindles in the tongue of the rhesus monkey and their absence in the cat's tongue, raises the question of whether this difference alters the structural and functional composition of, in particular, the rhesus monkey's hypoglossal nerve as compared to the same nerve in the cat. Using both random and complete sampling techniques, calibre spectra analyses were carried out on the following regions of the rhesus monkey's hypoglossal nerve: The medial and lateral end branches, and regions of the main trunk proximal and distal to the point where the ramus descendens is given off. In addition, the calibre spectrum of the lingual nerve was determined. The results suggested that neither the lingual nerve nor the proximal region of the hypoglossal nerve contained enough fibers of Group I diameter to justify the statement that they cintained spindle afferents. Distal to the point where the cervical contribution joins the hypoglossal nerve, however, the calibre spectrum exhibited a marked shift towards a closer resemblance to the spectra of limb muscle nerves in terms of the proportion of Group I diameter fibers. These findings suggested that although lingual spindle afferent fibers are present in the distal portion of the monkey's twelfth nerve, they may not reach the central nervous system in this nerve.
Cerebellar cortex of rat and other animals. A structural and ultrastructural study
Authors: O'Leary James L. , Petty Jerry , Smith Jeanne M. , O'Leary Mary , Inukai Joseph 
Published: January 2005

AbstractCerebellar cortex was studied in 100 rats and other animals, 15–30 days old, using Golgi, intravitam methylene blue, and ultrastructural methods. Marchi and Nauta provided certain controls. Degeneration of afferent terminals was sought following lesions of pons and olive.In normal material, emphasis was upon the changing field relations between folial summit, side wall, and sulcus, Many previous findings of Fox, Ramon y Cajal and Snider were confirmed, and the effort made to reconcile departures from characteristic axonal and dendritic configuration with cytoarchitectonic pattern.Mossy and climbing terminals were examined in normal and degenerated states, using Golgi and ultrastructural material. Climbing fibers in Golgi are described in detail, including variations in course and sites of branchings. Mossy degeneration was found 3–5 days after lesions of both pons and olive. The clearest evidence thereof was provided in ultrastructural material. Minor evidences of degeneration were also found in climbing fiber strands in both materials, but on gross degeneration was encountered. Corresponding Golgi material was used for visualizing intact fibers in the face of adequate lesions.Ultrastructure also provided evidence concerning the axon cap surround, the initial segment of the Purkinje axon, Comparison with these segmests in other cell types, and cross‐identification of synapses between axon types and the different cell profiles of Golgi material.
Distribution of monoamine‐containing nerve terminals in the brain of the painted turtle, Chrysemys picta
Authors: Parent A. 
Published: January 2005

AbstractThe distribution of monoamine (catecholamines and 5‐hydroxytryptamine)‐containing nerve terminals in the brain of the painted turtle (Chrysemys picta) was studied by means of the histofluorescence technique of Falck and Hillarp. The highest concentration of monoamine terminals in this reptilian brain occurs within the ventral region of the strio‐amygdaloid complex which on this basis may be related to the mammalian neostriatum (caudate nucleus and putamen). Numerous catecholamine type nerve endings are also present in several other regions of the turtle brain, namely: the dorsal cortical layer, the dorsolateral portion of the septum, the habenula, the nuclei dorsomedialis and dorsolateralis of the thalamus, the lateral part and median eminence of the hypothalamus, the tectum and the brain stem reticular formation (more especially its lateral edge). The greatest concentration of 5‐hydroxytryptamine (serotonin) type nerve endings is found in the dorsomedial portion of the septum, nucleus geniculatus lateralis, nuclei pretectalis, interpeduncularis and isthmi, the tectum and the reticular formation of the brain stem (more especially its medial portion). These monoamine nerve terminals belong to several groups of neurons whose cell bodies are located in the brain stem and, to a lesser degree, in the hypothalamus of the turtle.
The structure of the medial geniculate nucleus (MGN): A cyto‐ and myeloarchitectonic study in the squirrel monkey
Authors: Jordan Hans 
Published: January 2005

AbstractThe cyto‐ and myeloarchitectonic organization of the Medial Geniculate Nucleus (MGN) were investigated by means of several histological series sectioned in different planes. Eight hemispheres of normal adult monkeys (Saimiri sciureus) were used. The shape of the nucleus and its anatomical relationships to the surrounding structures were established. The MGN is ovoidshaped, forming a slight prominence at the ventrolateral surface of the brain. It is separated from the Lateral Geniculate Nucleus (LGN) by a capsule of myelinated fibers which surrounds the lateral and ventrocaudal aspects of the nucleus. The medial boundaries with the thalamic structures are difficult to determine.Three subdivisions of the nucleus were identified and their spatial interrelationships were determined: MGNa being composed of small irregularly shaped cells, MGNb containing both pale medium‐sized and large scattered multipolar nerve cells and MGNc with densely packed, medium‐sized and ovoid nerve cells.MGNa is located in the ventrocaudal portion of the nucleus, MGNb occupies most of the medial extent of MGN being laterally adjacent to MGNc.
Investigation of glial cells in semithin sections. III. Transformation of subependymal cells into glial cells, as shown by radioautography after 3H‐thymidine injection into the lateral ventricle of the brain of young rats
Authors: Paterson Jean A. , Privat A. , Ling E. A. , Leblond C. P. 
Published: January 2005

AbstractStrong labeling of the cells in the subependymal layer was produced by stereotaxic injection of 5 μCi of 3H‐thymidine into the left lateral ventricle of the brain of one and a quarter month old rats weighing about 100 gm. These animals were sacrificed by glutaraldehyde perfusion from two hours to 21 days later. Blocks of corpus callosum with adjacent subependymal and ependymal layers were excised from the injected and non‐injected sides, and embedded in Epon; 0.5 μ thick sections were radioautographed and stained with toluidine blue.In the subependymal region, on both injected and non‐injected sides, there was an immediate uptake of label by many cells followed by an increase and later a decrease in the percent cells labeled. In the corpus callosum while at first the percent labeling of glial cells was rather low, it did increase slowly with time and, after seven days, exceeded that in the subependymal region. These results were interpreted as indicating that cells arising in the subependymal layer had migrated into the corpus callosum.Up to four days after injection, most of the label in corpus callosum was present in immature‐looking cells resembling the cells of the subependymal layer and referred to as free subependymal cells. With time, the percent labeling decreased in these cells while increasing in some of the glial cells. A labeling peak was observed for light oligodendrocytes at four to seven days and for dark oligodendrocytes at 21 days, whereas labeling of medium shade oligodendrocytes occurred at intermediate times. The succession of labeling peaks indicated a sequence of development from free subependymal cells through light and medium shade to dark oligodendrocytes. Few astrocytes carried label at any time; those which did seemed to have arisen from the transformation of labeled free subependymal cells. Microglia were unlabeled at two hours, but their percent labeling was high at 4–14 days. While the labeling of other glial cells reflected their physiological behavior, the labeling of microglia was a consequence of the trauma produced by the injection 0f tracer into the ventricle.In conclusion, cells coming from the subependymal layer appear to migrate into the corpus callosum where, in 100 gm rats, many of them transform into oligodendrocytes and a few into astrocytes.
Stereological description of the anterior horn cervical cord of the adult rat. A quantitative study using the optical microscope
Authors: Mayhew T. M. , Momoh C. K. 
Published: January 2005

AbstractThe histometric properties of the most ventral, ventromedial and ventrolateral zones in the anterior horn of adult rat cervical enlargement were studied by quantitative optical microscopy. The spinal cord areas were identified in semi‐thin Araldite sections and unbiased samples of the test tissue were recorded on photomicrographs. By defining the tissue on the basis of a histometric model, it was possible to describe a number of important stereological parameters including compartmental volume proportions, cellular packing densities, perikaryal volumes and surface areas, and blood vessel length per unit volume.It was established that each cubic milimetre of tissue consists of approximately 0.85 mm3 of neuropil, 0.04 mm3 of blood vessels, 0.02 mm3 of neuroglial cells, 0.08 mm3 of motoneuron perikarya and 0.02 mm3 of small neuron perikarya. Roughly 0.11 mm3 of the neuropil compartment can be attributed to myelin. Estimates of cell body packing densities revealed an average of 44,950 neuroglial cells and 11,650 neurons per mm3. Small and motor neurons occur in approximately equal numbers. The average motoneuron has a perikaryal volume of 12,100 μm3 and a perikaryal surface area of 2,500 μm2. Corresponding figures for small neurons are 2,200 μm3 and 650 μm2. The average glial cell soma has a volume of 370 μm3. Differences between the nuclear volume proportions and nuclear size distributions of glial cells, small neurons and motoneurons are also reported. Each mm3 of tissue contains 1.2 metres of blood vessels, of average diameter 6.4 μm and with an outer surface area of 21 mm2.The results are presented and discussed in the context of data published by workers in other laboratories.