bluuebunny/crossref_metadata_2025_split huggingface dataset:
Motor nerve endings in extraocular muscles
Authors: Namba Tatsuji , Nakamura Toshio , Takahashi Akira , Grob David 
Published: January 2005

AbstractIn rat extraocular muscles, “en plaque” motor endings with subsynaptic folds were mainly localized at the terminal innervation band, and were present singly in muscle fibers having “Fidrillenstrucktur” and diameters of 18 to 30 μ. The “en grappe” motor endings without subsynaptic folds were found in the proximal and distal thirds of four rectus and two oblique muscles, and 10 to 16 endings were present in muscle fibers having “Felderstruktur” and diameters of 6 to 13 μ. The mean diameter of “en plaque” endings was 31.5 μ in the levator palpebrae and 32.1 μ in the rectus superior, which is larger compared with 27.1 μ in the tibialis anterior. The mean diameter of “en grappe” endings of the superior rectus muscle was 10.0 μ. The mean diameter of muscle fibers was 18.2 μ in the levator palpebrae, 18.5 μ in the superior rectus, and 33.1 μ in the tibialis anterior.
Retrohippocampal, hippocampal and related structures of the forebrain in the reeler mutant mouse
Authors: Caviness V. S. , Sidman R. L. 
Published: January 2005

AbstractRetrohippocampal, hippocampal and some related forebrain regions of the reeler mutant mouse were examined in cresyl violet and myelin stained preparations. All cortical structures are abnormal. The entorhinal cortex, parasubiculum, presubiculum, subiculum, and anterior hippocampal cortex share an anomaly of common quality. All lack an external plexiform layer and their neurons are not arranged in the usual laminae. The positions of neurons are not random, however. Cells of smaller average size and of polymorphic shape are grouped in an outer relatively narrow zone external to a broad zone of larger cells. The histological features of these two cell zones in the mutant are similar to the deep polymorphic cell stratum and the superjacent pyramidal field respectively in the normal animal, but their relative depths in the cortex are reversed. The histological pattern of the mutant hippocampus is less disturbed. Its external plexiform layer is well developed and, although the positions of some neurons are abnormal, there is an explicit laminar pattern and the cytological features of the individual hippocampal cytoarchitectonic fields are readily recognized.It appears from these observations that in a variety of cortical structures, even those which are most disturbed, the positions of neurons are systematically regulated, yet are controlled according to some rule that differs in normal and mutant. The basic developmental event which dictates eventual neuron position probably occurs early and its effects may depend on critical timing or precise location of interacting cells as influenced by the reeler locus.
An ultrastructural analysis of the photoreceptors of the squid and their synaptic connections. III. Photoreceptor terminations in the optic lobes
Authors: Cohen Adolph I. 
Published: January 2005

AbstractAn ultrastructural investigation of the optic lobe of the squid, Loligo pealei, revealed that the optic fibers, like those of Octopus, terminated in the outer plexiform layer in long carrot‐shaped bags containing small clear vesicles. The outer 4–5 μ of a terminal was devoid of conventional synapses but came into direct contiguity and specialized contacts with adjacent terminals. These specializations often included protrusions of finger‐like processes from one cell into another. At contact sites the intercellular space narrowed to a minimum of about 25 Å and immediately adjacent, in the cytoplasm of each contacting cell, was a sub‐membranal cistern. These contacts could be electrotonic junctions. The remainder of the receptor terminal received dendritic endings of post‐synaptic cells in deep invaginations. A pre‐synaptic accumulation of vesicles and increased membrane density was evident at these junctions. Neurons of the outer nuclear layer are described, as well as vertical fascicles of large pale neurites which pass through the outer nuclear and plexiform layers and which may include efferents to the retina. Specialized glial cells and a dense, intercellular material located in pools or clefts in certain regions of the cortex of the lobe are also noted.
The projection of nucleus lateralis dorsalis of monkey to basomedial temporal cortex
Authors: Locke Simeon , Kerr Clare 
Published: January 2005

AbstractRetrograde degeneration in thalamus was studied in eight Macaque monkeys following resection of basomedial temporal cortex. In addition to its known projection to the posterior cingulate region, nucleus lateralis dorsalis (LD) projects, perhaps via the fornix, to the parahippocampal gyrus. Convexal temporal neocortex receives fibers from the medial pulvinar (PM). Nucleus lateralis posterior (LP) may project to cortex intervening between the projection fields for LD and PM. A stereotactic lesion in fornix of one animal demonstrates corticothalamic projection to LD, LP and to a lesser extent to PM, AV, AM, and AD.
The topographic organization of spinal afferents to the lateral reticular nucleus of the cat
Authors: Künzle Heinz 
Published: January 2005

AbstractThe topographic organization of spinal afferents to the lateral reticular nucleus (LRN) has been reexamined in 34 adult cats. Two modifications of the Nauta technique were used to show secondary terminal degeneration resulting from circumscribed lesions at various levels of the spinal cord. The results demonstrate that the “inner segment” of LRN corresponding roughly to Brodal's magnocellular portion, receives fibers from spinal segments C1–D3, while the “outer segment” corresponding approximately to Brodal's parvocellular protion receives fibers from spinal levels below L3. The “middle segment” — a transitional zone between the two former portions — represents the spinal segments D4–L3. The ascending fibers terminate predominantly on the ipsilateral side; only few degenerated elements are noted within the contralateral nucleus. The subtrigeminal portion does not seem to receive afferent fibers from the spinal cord. This finding raises the question of nomenclature, which is briefly discussed in the light of the classical “nucleus funiculi lateralis” concept. Finally, the present data are consistent with electrophysiological data of Oscarsson, Rosén and collaborators according to which LRN represents spinal levels of convergent inputs from large as well as bilateral receptive fields rather than somatotopically arranged projections from peripheral sense organs.
Experimental reorganization of the cerebellar cortex. III. Regeneration of the external germinal layer and granule cell ectopia
Authors: Altman Joseph 
Published: January 2005

AbstractThe heads of Long‐Evans hooded rats were irradiated daily from day 3, 4 or 6 onward with schedules of low‐level x‐ray which differentially delayed the regeneration of the subtotally eradicated external germinal layer or prevented its regeneration altogether. Most schedules that permitted regeneration led to the arrest of many granule cells in the molecular layer where they formed an ectopic zone. The dendrites of ectopic granule cells had synapses with mossy fibers located in their vicinity in the molecular layer. The position of the ectopic zone varied in different lobules depending on several factors: the time when regeneration began, the estimated date of descent of granule cells, regional differences in cortical maturation and in the estimated upward growth rate of mossy fibers. Within the same lobule, the longer regeneration was delayed the higher in the molecular layer the differentiating and descending granule cells were captured by the apparently autonomously ascending mossy fibers. If regeneration started early and allowed the descent of granule cells into the granular layer (early irradiation) or if regeneration of granule cells was prevented altogether (late irradiation) an ectopic zone was not formed. The technique was used for estimating the normal growth pattern of mossy fibers in the different lobules.
Pretectal region and the pupillary light reflex. An anatomical analysis in the monkey
Authors: Carpenter Malcolm B. , Pierson Roberta J. 
Published: January 2005

AbstractThe effects of discrete lesions in the pretectal region of the monkey upon the pupillary light reflex were studied, using infrared pupillography. Resulting degeneration was studied by silver impregnation methods.The nucleus of the optic tract (NOT) and the sublentiform nucleus (SL) project fibers to the nuclei of the posterior commissure (NPC) and to portions of the ipsilateral inferior pulvinar, pregeniculate nucleus and dorsal lateral geniculate body. NPC gives rise to the bulk of the fibers in the posterior commissure (PC) which largely terminate upon contralateral cells of NPC. Some fibers arising from NPC enter the ipsilateral central gray and terminate bilaterally primarily upon cells of the medial visceral columns of the oculomotor complex (OMC). These fibers partially decussate ventral to the aqueduct.Fibers from the olivary nucleus (ON) cross in the PC and project to terminations upon: (1) large cells of the opposite ON and (2) the anterior median nuclei and the contralateral lateral visceral cell column of OMC. NOT, and possibly ON, give rise to fibers crossing in PC that project to the contralateral accessory optic tract nucleus (AOTN).Unilateral lesions that fairly selectively destroy parts of NOT, ON, SL, NPC, central fibers of PC or the nucleus of the pretectal area (NPA), produce neither miosis, mydriasis, anisocoria, nor do they impair direct or consensual pupillary light reflexes. Unilateral lesions, which impair pupillary light reflexes, involve multiple structures, such as NPC, PC and lateral regions of the central gray.
Cytoarchitecture and somatic sensory connectivity of thalamic nuclei other than the ventrobasal complex in the cat
Authors: Jones E. G. , Burton H. 
Published: January 2005

AbstractThis study is a re‐examination, using autoradiographic and axonal degeneration methods, of the distribution of spinal, dorsal columnlemniscal and cortico‐thalamic fibers within the thalamus of the cat. The emphasis was placed upon making an exact cytoarchitectonic delineation of regions outside the ventrobasal complex which receive spino‐thalamic fibers and corticofugal fibers arising in the sensory‐motor regions of the cerebral cortex.It is concluded, in agreement with Boivie ('70, '71a,b) that spino‐thalamic fibers arising below the level of the lateral cervical nucleus terminate, not in the ventrobasal complex, but in a recognizable portion of the ventrolateral complex adjacent to the ventrobasal complex. This region appears to be also the thalamic relay for Group I muscle afferents. Combined experiments in which, in the same animal, the dorsal column‐lemniscal path was labeled autoradiographically and the spino‐thalamic path by the Nauta method, indicate virtually no overlap of the two systems in the ventral nuclear complex.Spinal fibers also end in the medial division of the posterior group (Pom), which extends posteriorly as a small‐celled zone along the ventromedial aspect of the magnocellular medial geniculate nucleus. Reports of spinal terminations in the magnocellular nucleus proper may result from a failure to recognize the extent of Pom. A third part of the thalamus receiving spinal fibers consists of a posteriorly situated group of large, deeply staining cells belonging to the central lateral nucleus which lie mainly posterior to the internal medullary lamina and which, as Mehler ('69) has mentioned, have previously been confused with the centre médian and parafascicular nuclei.Corticofugal fibers arising in the somatic sensory cortex terminate in both the ventrobasal complex and the spinal part of the ventrolateral complex as well as in the central lateral nucleus and Pom and this confirms the work of Rinvik ('68a). Those arising in the motor cortex terminate only in (a different part of) the ventrolateral complex and in the centre médian nucleus.
The connections between horizontal cells and photoreceptors in the retina of the cat: Electron microscopy of Golgi preparations
Authors: Kolb Helga 
Published: January 2005

AbstractElectron microscopy of Golgi preparations reveals that the dendritic terminals of horizontal cells in the cat's retina are connected only to cones. The axon terminals of these horizontal cells connect exclusively to rods. Dendritic and axonal terminals of horizontal cells penetrate the photoreceptor endings to become lateral elements of the invaginations. In addition this study suggests that each cone is in contact with more than one horizontal cell and that each rod connects to more than one axon terminal system. The horizontal cells of the cat are similar to those of the rhesus monkey in that the rod and cone connections are segregated to different portions of these cells.
The mode of innervation of portions of the anterior and posterior pretectal nuclei of the rabbit by axons arising from the visual cortex
Authors: Giolli Roland A. , Towns Lex C. , Haste David A. 
Published: January 2005

AbstractIn sections processed by the Cajal method, two distinct systems of fibers can be recognized within the dorsolateral portion of the anterior pretectal nucleus and the lateral portion of the posterior pretectal nucleus of the rabbit. One is a rostrocaudal system which consists of fiber bundles oriented in parallel with the superior quadrigeminal brachium; some fibers of this system mingle with the fibers of this brachium. The other is a lateromedial system which is composed of fibers directed perpendicularly to those of the rostrocaudal system. After lesions of the visual cortex, the study of the Nauta sections reveals that there are degenerating fibers present within both systems in the portions of the anterior and the posterior pretectal nuclei studied. The degenerating rostrocaudal fibers are found to send collateral branches into the lateromedial fiber system present in these portions of the pretectal nuclei. Most, if not all, of the degenerating lateromedial fibers are the continuations of these collateral branches given off by the degenerating rostrocaudal fibers, and at the same time represent the terminal portions of corticopretectal axons. These conclusions are based upon four of the present findings: (i) the presence of degenerating rostrocaudal fibers that branch in the zones of degenerating lateromedial fibers but in no other parts of the pretectal nuclei studied; (ii) the common orientation shared by these collateral branches and the degenerating lateromedial fibers at any one location, suggesting that the two elements represent portions of the same fibers; (iii) the morphology of the degenerating lateromedial fibers with their many short side branches indicating that these fibers are the terminal segments of the corticopretectal axons (some of the degenerating rostrocaudal fibers also have short side branches along their length which would appear to represent terminal side branches); (iv) our failure to demonstrate degenerating rostrocaudal fibers which pass into the lateromedial fiber system without branching. In the Golgi‐Kopsch preparations from normal brains it has been possible to identify undegenerated lateromedial fibers with the same morphology as the degenerating lateromedial fibers seen in the Nauta sections.
DNA constancy in neurons of the human cerebellum and spinal cord as revealed by Feulgen cytophotometry and cytofluorometry
Authors: Fujita Setsuya 
Published: January 2005

AbstractNeuroblasts and neurons of the human cerebellum and spinal cord from the eighth fetal week to 68 years of age were prepared as smears and the DNA content of individual cells was measured by Feulgen cytophotometry and microfluorometry. DNA constancy of large and small neurons as well as neuroblasts was confirmed by the two methods. These findings accord with autoradiographic observation that neuroblasts, once differentiated from matrix cells, do not synthesize DNA.
Morphology of afferent and efferent synapses in hearing organ of goldfish
Authors: Nakajima Yasuko , Wang D. W. 
Published: January 2005

AbstractThe sacculus, the hearing organ, of the goldfish was fixed with three different kinds of fixatives: osmium tetroxide, glutaraldehyde and formaldehyde. Three kinds of synapses are encountered in the sensory epithelium: the synapse between the hair cell and the afferent nerve ending, the synapse between the efferent nerve ending and the hair cell, and the synapse between the hair cell and the afferent nerve ending, there are synaptic vesicles about 370‐430 Å in average diameter in the hair cell side of the junction. The vesicles are always round in dependent of the fixative used. In the other two kinds of synapses, the efferent ending contains smaller vesicles about 310‐360 Å in average diameter. The shape of the vesicles changes according to the fixative used; round in osmium tetroxide‐fixed materials, and elongated in aldehydefixed materials. The synapse between the hair cell and the afferent nerve ending in excitatory in nature, while the other two types of synapses are thought to be inhibitory in nature.
Evolution of reptilian visual systems: Retinal projections in a nocturnal lizard, Gekko gecko (linnaeus)
Authors: Northcutt R. Glenn , Butler Ann B. 
Published: January 2005

AbstractOn the basis of the development of the dorsal ventricular ridge of the telencephalon, lizards can be divided into a type I group, to which Gekko and the majority of lizard families belong, and a type II group with more derived features, of which Iguana is representative. Most studies of retinal projections have utilized lizards of the type II group, which are adapted to a diurnal niche. Gekko gecko is differently adapted in that it is nocturnal. Study of the retinal projections was undertaken in Gekko gecko in order to insure that conclusions regarding the pattern of retinal pathways in saurians would be based on a sample which was more representative of the total range of variation.Unilateral removal of the retina by suction cannula was carried out on 12 adult specimens of Gekko gecko. After survival times of 10 to 74 days, brains were processed with various silver methods. The retina projects contralaterally to the pars dorsalis and pars ventralis of the lateral geniculate nucleus and the pars ventralis of the ventrolateral nucleus in the thalamus, nuclei geniculatus pretectalis, lentiformis mesencephali, and posterodorsalis in the pretectum, layers 8–14 of the optic tectum and nucleus opticus tegmenti. Additionally, the retina projects ipsilaterally to the dorsal and ventral lateral geniculate nuclei and to the pretectal nuclei, as well as to the optic tectum, particularly layers 8 and 9.The finding of ipsilateral retinothalamic projections in Gekko supports the idea that this pathway is generalized among saurians. However, presence of ipsilateral retinothalamic projections and the degree of binocular overlap cannot be correlated when lizards, snakes, crocodiles, and turtles are compared. The functional significance of this pathway therefore remains obscure. Ipsilateral retinotectal projections have not been previously described in land vertebrates other than mammals. Whether their presence is correlated with nocturnal visual habits or is generalized among type I lizards remains to be determined. The pattern of retinal projections has been studied in too few representatives of non‐mammalian land vertebrates to presently permit conclusions regarding the origin of non‐decussating pathways.
A stereotaxic atlas and technique for forebrain nuclei of the goldfish, Carassius auratus
Authors: Peter R. E. , Gill V. E. 
Published: January 2005

AbstractA stereotaxic apparatus and technique for electrode placement in forebrain nuclei of the goldfish is described. An atlas of forebrain nuclei is given. Some new nuclear regions are described and the nomenclature of several nuclei is discussed.
The ventral spinothalamic tract and other ascending systems of the ventral funiculus of the spinal cord
Authors: Kerr Frederick W. L. 
Published: January 2005

AbstractThe ascending degeneration resulting from experimental lesions of the ventral funiculus of the spinal cord of Macaca mulatta has been studied using the Nauta technique and its variants.The ventral spinothalamic tract is shown to be independent entity with respect to the lateral spinothalamic tract; its fibers are widely distributed in the ventral funiculus and it establishes connections with the brain stem and thalamus which are analogous but not identical to those of the latter. Its role in the relay of nociceptive input is discussed in view of the similarity in hodology of the two systems and it is proposed that it may be responsible for the failure of anterolateral cordotomy to control pain on a long term basis. Other ascending systems in the ventral funiculus include the spino‐olivery and spino‐reticular tracts, as well as minor connections to the N. of Edinger‐Westphal, the red nucleus and the superior colliculus. The projections from the ventral quadrant of the spinal cord to the brain stem are almost entirely ipsilateral until the rostral mesencephalon is reached, at which level the N. of Darkschewitz receives both ipsilateral and crossed input; the magnocellular nuclues of the medial geniculate body receives a small contribution which is mainly ipsilateral. In the thalamus the VPL receives predominantly ipsilateral projections while the input to the paralaminar nuclei is only slightly less pronounced contralaterally than ipsilaterally.
The efferent connections of the suprachiasmatic nucleus of the hypothalamus
Authors: Swanson L. W. , Cowan W. M. 
Published: January 2005

AbstractThe efferent connections of the suprachiasmatic nucleus of the hypothalamus have been studied in the rat by the injection of 3H‐proline into the nucleus and the surrounding regions of the rostral hypothalamus, and by the injection of the enzyme marker, horseradish peroxidase, into the region of the ventromedial hypothalamic nucleus. After an injection of 3H‐proline confined to the ventral portion of the suprachiasmatic nucleus, transported label can be followed, in the autoradiographs, dorsally and caudally in the periventricular area as far as the caudal end of the ventromedial nucleus, into the triangular area between this nucleus and the arcuate nucleus, and along the ventral aspect of the tuberal region, just lateral to the ventromedial nucleus. A small number of silver grains are also seen over the internal lamina of the median eminence. No label can be followed rostrally or immediately lateral to the nucleus. Comparable injections into adjoining regions of the hypothalamus (especially the anterior hypothalamic area, the medial preoptic area, and the retrochiasmatic region) show transported label over the same regions, but with a somewhat different pattern of grain distribution; in addition, the anterior hypothalamic area shows an extensive projection through the medial forebrain bundle to the mammillary and supramammillary nuclei, the midbrain tegmentum, and certain of the midline thalamic nuclei. Although it is difficult in our autoradiographs to distinguish between the course of the efferent fibers from the suprachiasmatic nucleus and the zones in which they terminate, our evidence favors a termination among the cells of the periventricular area, and upon dendrites of the cells in the ventromedial, dorsomedial and arcuate nuclei, which extend beyond the limits of the nuclei into the periventricular area and to the area beneath the ventromedial nucleus.