bluuebunny/crossref_metadata_2025_split huggingface dataset:
The insular formations of the dolphin brain: Quantitative cytoarchitectonic studies of the insular component of the limbic lobe
Authors: Jacobs Myron S. , Galaburda Albert M. , McFarland Willard L. , Morgane Peter J. 
Published: January 2005

AbstractThe large insula of the bottlenose dolphin consists of radial gyri arising, in fanlike fashion, from the transverse insular gyrus, and is covered completely by the frontal, parietal, and temporal opercula. On cytoarchitectonic grounds, the dolphin insula is divided into anterior, middle, and posterior sectors that may be the equivalent of the three similar sectors present in the primate insula. Rostrocaudally, these sectors become increasingly more homogeneous and less laminated. Within each sector progressive differentiation occurs in the direction of the circular sulcus. A transitional cortex, the peripaleocortex in the transverse insular gyrus, is interposed between the prepiriform and the periamygdalar cortex and the proisocortex of the insula proper. This peripaleocortex consists of outer and inner cellular strata separated by a hypocellular lamina dissecans. The outer cell stratum is continuous with layers II and III of the insular proisocortex; the more prominent inner stratum is continuous with proisocortical layers V and VI; the intervening lamina dissecans becomes partially filled, mostly with modified pyramidal cells of medium size that may constitute an incipient layer IV. A band of myelinated fibers corresponding to the external band of Baillarger is found within the lamina dissecans. The anterior insular sector is characterized by distinct lamination and a well‐defined, ribbonlike layer Va. In the middle sector, the cortex is internodense and lamination is less clear. The posterior sector is even less laminated and tends to be externodense. Within each sector, lamination becomes clearer in the direction of the circular sulcus. Furthermore, the rostrocaudal architectonic changes suggest a possible transition from a motor‐type to a sensory‐type cortex. Beyond the insula, the architecture of the opercular cortices reflect, in turn, the influences of the insular sectors.
Fractured cutaneous projections to the granule cell layer of the posterior cerebellar hemisphere of the domestic cat
Authors: Kassel Jeffrey , Shambes Georgia M. , Welker Wally 
Published: January 2005

AbstractSnider's pioneering studies of tactile responses in the cerebellar cortex of cats and monkeys suggested that posterior regions of the cerebellar hemispheres receive somatotopically organized projections. However, recent studies in rats, using high‐density, in depth microelectrode mapping methods, have shown that tactile projections to the granule cell layer of the cerebellar hemispheres are somatotopically disrupted. We reexamined the Organization of cutaneous projections to eortibellar hemispheric cortex in cats by using micromapping methods.Natural stimulation of cutaneous surfaces evokes short‐latency (mossy‐fiber‐induced) multiple unit responses in the cerebellar granule cell layer of crus II and paramedian lobule in both ketamine‐ and barbiturate‐anesthetized cats. Facial structures are represented in several of the most caudo‐medial folia of crus II as well as in three of the rostral folia of the paramedian lobule. In several of these paramedian folia, facial projections are interspersed with projections from the forelimb. Forelimb structures alone are represented in two intermediate folia of the paramedian lobule. No cutaneous projections were found from the trunk or hindlimb. All projections were from ipsilateral receptive fields.In four folia of crus II and six folia of the paramedian lobule, cutaneous projections form a mosaic of patchlike projections. Within single patches, projections are somatotopically organized, but projections to adjacent patches come from noncontiguous body regions. Within a single folium, a particular facial region may be represented in two or three spatially separated patches. Facial patches are small, usually less than 1 mm2. Forelimb patches are usually larger, often extending the full length and breadth of a folial crown. Patches with like receptive fields are not organized in zonal sagittal strips. Rather than being somatotopically organized, cutaneous mossy fiber projections to granule cells in cats, as in rats, reveal a more complex mosaic pattern of organization.
The cytoarchitecture and some efferent projections of the centromedian‐parafascicular complex in the lesser bushbaby (Galago senegalensis)
Authors: Pearson J. C. , Norris J. R. , Phelps C. H. 
Published: January 2005

AbstractThe morphology of neurons in the centromedian (CM) and parafascicular (PF) nuclei in the lesser bushbaby (Galago senegalensis) is described in coronal and horizontal brain sections using Golgi‐, horseradish peroxidase (HRP)‐, and Nissl‐staining procedures. The CM contains two types of cells referred to as principal neurons and Golgi type II (like) neurons. Cell bodies of principal neurons are relatively large in cross‐sectional area (mean = 130.42 μm2), round to spindle in shape, support short somatic spines, and give rise to three to five primary dendrites. The dendrites branch in a “radiate” pattern and possess numerous appendages consisting of narrow, stalk‐supported swellings. The presumed axons of these cells are impregnated only in their initial segments. On the basis of the similarity of principal neuron soma shapes and cross‐sectional areas with those of HRP‐reactive somata following cortical HRP implantation, it is concluded that at least some of the principal neurons in Galago CM project to somatic sensory‐motor cortex. Golgi type II (like) neurons have small (mean = 79.43 μm2), round somata which support several spines and give rise to three to four small‐diameter dendrites. The dendrites are infrequently branched, sinuous in their courses, and give rise to complex appendages and beaded processes. However, the axons of these cells could not be seen to ramify in the immediate vicinity of the dendritic field or soma, and there is considerable overlap in the cross‐sectional areas of Golgi type II (like) neurons seen in Golgi preparations and HRP‐stained cells following cortical implant of HRP pellets. Consequently, although Golgi type II (like) cells have traits characteristic of classically described intrinsic neurons, a cortical projection of these cells cannot be ruled out by the present study.The parafascicular nucleus contains two groups of large, radiate cells characterized by the presence or absence of somatic spines. Cells with somatic spines also contain numerous appendages on the dendrites. Cells without somatic spines support only a few, isolated, short dendritic appendages. Numerous small cell‐bodied neurons are present in Nissl‐stained sections of PF; however, cells which resemble Golgi type II neurons were not observed in the PF in the present Golgi‐impregnated material. In contrast to the CM, the large cell‐bodied neurons in PF were not found to project to somatic sensory‐motor cortex in Galago.
A sympathetic projection from sacral paravertebral ganglia to the pelvic nerve and to postganglionic nerves on the surface of the urinary bladder and large intestine of the cat
Authors: Kuo David C. , Hisamitsu Tadashi , De Groat William C. 
Published: January 2005

AbstractAnatomical and electrophysiological experiments have demonstrated a prominent projection from the sacral sympathetic chain via the pelvic nerve to postganglionic nerves on the surface of the urinary bladder and the Large intestine of the cat. Retrograde labeling studies revealed that the pelvic nerve, which is generally believed to carry primarily parasympathetic axons, has a considerable population of sympathetic fibers originating mainly from the S1‐S3 paravertebral ganglia. The number of sympathetic neurons projecting to the pelvic nerve (2,100) was about.75% of that projecting to the pudendal nerve (2,900), a somatic nerve which would be expected to carry a large sympathetic fiber constituent. Sympathetic neurons projecting to the pudendal nerve were located primarily in the L6‐S2 ganglia. Electrophysiological studies confirmed the presence of a sympathetic pathway from the paravertebral ganglia to the pelvic viscera. Electrical stimulation (thresholds 1.5–3 V) of the lumbar sympathetic chain evoked firing in the pelvic nerve and in postganglionic nerves on the surface of the colon and bladder at latencies of 60–150 msec. The responses were unaffected by cutting the chain one segment rostral to the site of stimulation, but were abolished by the administration of a ganglionic‐blocking agent (tetraethylammonium). The responses on the colon and bladder postganglionic nerves were also abolished by transection of the pelvic nerve. The conduction velocity in the sympathetic postganglionic axons was approximately 1 m/second.In summary, these studies indicate that the pelvic nerve, like somatic nerves, receives a prominent projection from the sympathetic chain ganglia. The function of this sympathetic paravertebral pathway and its relationship with prevertebral innervation of the pelvic organs remains to be established.
Abnormal central visual pathways in the brain of an albino green monkey (Cercopithecus aethiops)
Authors: Guillery R. W. , Hickey T. L. , Kaas J. H. , Felleman D. J. , Debruyn E. J. , Sparks David L. 
Published: January 2005

AbstractThe visual pathways of an albino green monkey have been studied electrophysiologically and by autoradiographic methods. The monkey had a white coat and pink eyes; it had a strabismus and a nystagmus. When comparisons were made with normal macaque and green monkeys, several abnormalities could be defined. In the retina there was no foveal pit. A whole mount preparation showed a central area of high ganglion cell density in which the ganglion cells were significantly larger than the most central ganglion cells of a normal monkey. More peripheral retinal areas showed an apparently normal distribution of ganglion cell sizes and packing densities. Within the optic tract the number of uncrossed retinofugal fibers was less than normal, the part of the tract that represents central vision showing almost no uncrossed component. The uncrossed input to the lateral geniculate nucleus and to the superior colliculus was similarly reduced. Regions normally receiving ipsilateral afferents from the central retina were innervated exclusively by crossed afferents. The pathways to the magnocellular geniculate layers showed a more extensive abnormality than did the pathways to the parvicellular layers. Not only were the afferents to the geniculate layers abnormal, but the laminar pattern in the nucleus was also abnormal. The distinction between magno‐ and parvicellular layers was less clear than normal in some parts of the nucleus, and there were a number of abnormal laminar fusions. Within the visual cortex it was possible to demonstrate a normal mapping of the contralateral visual field through the contralateral nasal retina and through the peripheral parts of the ipsilateral temporal retina. The central parts of the temporal retina mapped abnormally in the contralateral visual cortex, so that there was a monocular map of the central parts of the visual field forming as a mirror reversal of the normal map. The normal map of the contralateral hemifield formed columns that alternated with the abnormal map of the ipsilateral hemifield. The peripheral parts of the visual field were represented as ocular dominance columns, demonstrable electrophysiologically and also by the transneuronal transport of3H‐proline.
Light and electron microscopic studies of the distribution of microtubule‐associated protein 2 in rat brain: A difference between dendritic and axonal cytoskeletons
Authors: Bernhardt R. , Matus A. 
Published: January 2005

AbstractA specific antiserum was used to ascertain the distribution of microtubule‐associated protein 2 (MAP2) in the rat brain at the light and electron microscope levels. Light microscopy showed MAP2 to be present only in neurons, and only in the dendrites and the perikaryon of each cell. This same polarized distribution pattern was found in the Purkinje, Golgi, basket, stellate, and granule cells of the cerebellum, and also in neurons of the hippocampus, the olfactory bulb, and the midbrain. While labelling of the dendritic arborization was extensive and intense, MAP2 density tended to decrease in the proximal dendritic trunk. Particularly in large neurons (e.g., Purkinje, Golgi, and pyramidal cells), staining was reproducibly weaker in the cell body than in the main dendrites. Dendritic contours generally appeared smooth, without any evidence of staining of dendritic spines. An electron microscope examination of the cerebellum confirmed the presence of MAP2 reactivity in neurons and its absence from axons and non‐neuronal cells. MAP2 in dendrites was associated with microtubules, while MAP2 in neuronal perikarya was associated with polyribosomes. There was no evidence of specific staining in dendritic spines and in postsynaptic densities. MAP2 is a novel dendritic marker and labels part of a specific dendritic cytoskeleton, different from that in axons and non‐neuronal cells.
Central neural connections of the pineal organ and retina in the teleost Gasterosteus aculeatus L.
Authors: Ekström Peter 
Published: January 2005

AbstractThe relations of the central neural connections of the pineal organ to those of the retinae of the lateral eyes were investigated in the three‐spined stickleback, Gasterosteus aculeatus L. (Teleostei), by anterograde and retrograde transport of horseradish peroxidase (HRP). HRP was applied to the crushed pineal stalk and/or injected into the left or the right eye. Both pineal and retinal efferents project to area praetectalis, dorsal and ventral thalamic areas, and dorsal tegmentum. The most notable overlapping occurs in nucleus commissurae posterioris of area praetectalis. Pineal efferents also innervate the habenular nuclei and dorsal hypothalamus, while retinal efferents innervate rostral hypothalamus, ventrolateral thalamus, and tectum opticum. A small number of retinofugal axons recross and innervate the ipsilateral nucleus anterioris periventricularis and area praetectalis. After intraocular HRP injections, labeled perikarya were located both in retinofugal terminal areas and in areas not receiving direct retinal input, such as the telencephalic nucleus olfactoretinalis, deep tectal layers, and an area rostroventral to nucleus dorsolateralis thalami. No neurons afferent to the pineal organ were demonstrated. The close association of pineal efferents with retinofugal and possible retinopetal elements is in accordance with the view that both systems are potential neural mediators of photoperiodic events in the teleostean circadian system.
Monoclonal antibody identifies a 63,000 dalton antigen found in all central neuronal cell bodies but in only a subset of axons in the leech
Authors: McKay Ronald , Johansen Jørgen , Hockfield Susan 
Published: January 2005

AbstractThe monoclonal antibody Lan3‐8 binds to all the neuronal cell bodies in midbody, head, tail, and supraesophageal ganglia in the mud leech (Haemopis marmorata) and the medicinal leech (Hirudo medicinalis). In contrast to the general distribution of the antigen in cell bodies it is only found in a subset of axons, where electron microscopy suggests that it may be associated with a cytoskeletal filament system. Immunoblotting shows that the antibody binds to a 63,000 dalton band that is protease‐sensitive. The same 63 kilodalton (kd) ‐antigen is found in all regions of the central nervous system, in proteins isolated from connectives (axons alone), and from handdissected identified cell types. The molecular weight and electron microscopic localization raised the possibility that this antigen is the core neuro‐filament protein, but the antigen does not comigrate with 67‐kd intense coomassie blue band that binds another anti‐intermediate filament antibody. The supraesophageal ganglia are known to have a different developmental origin from the other structures in the leech central nervous system. Two‐dimensional gel electrophoresis and silver staining show that, like the 63‐kd antigen, many other proteins are very similar in these developmentally distinct neural structures.
Axonal and dendritic development of substantia gelatinosa neurons in the lumbosacral spinal cord of the rat
Authors: Bicknell H. Ryan , Beal John A. 
Published: January 2005

AbstractIn the present study, developing neurons of the substantia gelatinosa (SG) are examined at short interval sequential stages from 15 days of gestation through 20 days postpartum. Rapid Golgi preparations are utilized to examine axonal and dendritic development and toluidine blue preparations are employed to study the overall growth pattern of SG cells by measuring changes in mean cell body area. Results show that there are two maturation periods, which involve two separate groups of SG neurons. The sequence and pattern of development for each group is different. The first period occurs prenatally and involves the axonal and dendritic development of presumptive projection and propriospinal neurons. In classical terminology, these cells can be classified as limiting, large find small central, and transverse cells. These neurons have axons that enter the white matter and their dendritic arbors develop through a relatively simple process of elongation and branching.The second maturation period occurs postnatally and involves the development of presumptive nonprojection intrinsic neurons that have axons which remain within the gray matter. These neurons are identified as islet, stalk, inverted stalklike, and vertical cells. Unlike projection or propriopinal neurons, the intrinsic nonprojection neurons sprout numerous short, beaded dendrites that radiate from the cell body in a starlike fashion. Star‐shaped cells undergo a metamorphosis involving a rearrangement of dendrites along adult dendritic patterns.Measurements taken from toluidine blue preparations indicate that the nonprojection intrinsic population makes up the greatest percentage of SG neurons, as evidenced by a marked increase in the size of the average SG nerve cell during the second maturation period.
Anatomical consequences of long‐term monocular eyelid closure on lateral geniculate nucleus and atriate cortex in squirrel monkey
Authors: Tigges Margarete , Henrickson Anita E. , Tigges Johannes 
Published: January 2005

AbstractThe effects of long‐term monocular deprivation on the geniculostriate system in squirrel monkeys were studied with neuroanatomical methods. Four neonates were visually deprived by monocular eyelid suture during their first 10 days of life and survived form 9 to 40 months. In the lateral geniculate nucleus (LGN), deprivation resulted in severe cell size changes. Neurons in the deprived laminae were smaller compared to those in the undeprived laminae. Deprivation left the reciprocal connections between LGN and striate cortex intact: After horseradish peroxidase (HRP) injections into striate cortex, retrogradely transported enzyme labeled a wedge of neurons in deprived and undeprived LGN laminae; anterogradely transported HRP filled preterminal and terminal axons in this wedge.Following 3H‐proline injections into the deprived eye for transneuronal transport, autoradiography showed in the ipsilateral striate cortex a silver grain distribution over most of layer IVc similar to that in normal squirrel monkeys, except for a small strip in the anterior calcarine fissure. Here, a few, irregularly spaced “patches” of higher grain density occurred deep in layer IVc Layer IVc of contralateral area 17 was also uniformly labeled over most of its extent, except for a very few and inconspicuous accumulations of slightly increased silver grains. After visual stimulation of the deprived eye, the 14C‐2‐deoxyglucose method showed in the contralateral striate cortex some alternating “patches” of higher uptake superimposed on the heavy labeling in layer IVc. Layer IVc in the ipsilateral cortex was more uniformly labeled. Regularly spaced arrays of labeled “puffs” in layers II/III were present in both hemispheres. Cytochrome oxidase staining showed on change in the distribution pattern of the enzyme in the deprived monkeys from the basic pattern of normal adults. No changes in cell sizes were found in layer IVc in cresyl‐violet‐acetate‐stained sections. These results lead to the conclusion that in area 17 of squirrel monkeys there is no distinct segregation of inputs from the two eyes into anatomically discrete ocular dominance columns and they support the view of a predominantly binocular organization of area 17.
The distribution and origin of a novel brain peptide, neuropeptide Y, in the spinal cord of several mammals
Authors: Gibson S. J. , Polak J. M. , Allen J. M. , Adrian T. E. , Kelly J. S. , Bloom S. R. 
Published: January 2005

AbstractThe distribution of neuropeptide Y [NPY]‐immunoreactive material was examined in the spinal cord and dorsal root ganglia of rat, guinea‐pig, cat, marmoset, and horse. Considerable concentrations of NPY and similar distribution patterns of immunoreactive nerve fibres were found in the spinal cord of all species investigated. The dorsal root ganglia of the cat and the horse contained numerous immunoreactive nerve fibres, but in these species, as in the other three studied [rat, guinea‐pig, marmoset], no positively stained cell bodies were found. Neuropeptide Y‐immunoreactive nerves were observed at all levels of the spinal cord, being most concentrated in the dorsal horn. In the rat, guinea‐pig, and marmoset, there was a marked increase of NPY‐immunoreactive fibres in the lumbosacral regions of the spinal cord, and this was reflected by a considerable increase of extractrable NPY. Estimations of NPY‐immunoreactive material in the various regions of the rat spinal cord were as follows: cervical, 13.8 ±1.0; thoracic, 21.1 ±2.5; lumbar, 16.3 ±2.9; sacral, 92.4 ±8.5 pmol/gm wet weight of tissue ±SEM. In the ventral portion of the guinea‐pig spinal cord they were as follows: cervical, 7.1 ±1.2; thoracic, 8.2 ±3.6; lumbar, 22.6 ±7.0; sacral, 36.7 ±9.5 pmol/gm wet weight of tissue ±SEM. Analysis of spinal cord extracts by reverse phase high performance liquid chromatography [HPLC] demonstrated that NPY‐immunoreactive material elutes in the position of pure NPY standard.No changes in the concentration and distribution of the NPY‐like material in the rat spinal cord were observed following a variety of surgical and pharmacological manipulations, including cervical rhizotomy, sciatic nerve section and ligation, and local application of capsaicin [50 mM] to one sciatic nerve. It is therefore suggested that most of the NPY‐immunoreactive material in the spinal cord is derived either from intrinsic nerve cell bodies or from supraspinal tracts.