bluuebunny/crossref_metadata_2025_split huggingface dataset:
A quantitative dendritic analysis of wernicke's area in humans. II. Gender, hemispheric, and environmental factors
Authors: Jacobs Bob , Schall Matthew , Scheibel Arnold B. 
Published: January 2005

AbstractThis quantitative Golgi study extends our investigation of relationships between cortical dendrite systems in humans and higher cognitive functions. Here we examine the relationship between the basilar dendrites of supragranular pyramidal cells in Wernicke's area and selected intrinsic (i.e., gender and hemisphere) and extrinsic (i.e., education and personal history) variables. Tissue was obtained from 20 neurologically normal right‐handers: 10 males (Mage = 52.2) and 10 females (Mage = 47.8). Several independent variables were investigated: GENDER (male, female), HEMISPHERE (left, right), and EDUCATION (less than high school, high school, and university). These were evaluated according to Total Dendritic Length, Mean Dendritic Length, and Dendritic Segment Count. A distinction was made between proximal (1st, 2nd, and 3rd order) and ontogenetically later developing distal (4th order and above) branches.There was significant interindividual variation in dendritic measurements, which roughly reflected individuals' personal backgrounds. Females exhibited slightly greater dendritic values and variability than males across the age range examined. On the whole, the left hemisphere maintained a slight advantage over the right hemisphere for all dendritic measures when all subjects were pooled, but these differences were not in a consistent direction across individuals. Education had a consistent and substantial effect such that dendritic measures increased as educational levels increased. Dendritic differences between independent variable levels were most clearly illustrated in the total dendritic length of 3rd and 4th order branches. Distal dendritic branches appeared to exhibit greater epigenetic flexibility than proximal dendrites. The present findings concur with environmental enrichment research results in animals and suggest that dendritic systems in humans function as a sensitive indicator of an individual's (a)vocational activities. © 1993 Wiley‐Liss, Inc.
Retinal projection to the olfactory tubercle and basal telencephalon in primates
Authors: Mick Gérard , Cooper Howard , Magnin Michel 
Published: January 2005

AbstractThe retinal projection to the basal telencephalon was studied in eight species of primates from the suborders Strepsirhini and Haplorhini, including one anthropoid primate, the gibbon. Animals received an intraocular injection of tritiated amino acids and the distribution of retinal fibers and terminals was demonstrated by autoradiographic techniques in horizontal and coronal sections. In all species a discrete group of labeled retinal fibers is observed to branch off from the dorsolateral aspect of the optic tract at the level of the suprachiasmatic nucleus. These fibers, destined to the basal telencephalon, are topographically distinct from the retinal fibers which innervate the suprachiasmatic nucleus and medial hypothalamic regions. The fibers of the retinotelencephalic tract course dorsally above the supraoptic nucleus through the lateral hypothalamic area and then proceed further rostrally and laterally below the diagonal band of Broca towards the olfactory tubercle. Within the olfactory tubercle, terminal distribution of label is observed in the mediocaudal region along the granular cell layer II. In the macaque this cellular layer shows a characteristic thickening in the region of retinal terminals which is evident in both coronal and horizontal section. In some species this labeled region is seen within the superficial bulge of the tubercle on the ventral aspect of basal telencephalon. In all Primates the retinal projection to olfactory tubercle is bilateral. In prosimians label is predominantly contralateral to the injected eye, in New World monkeys label is equally distributed on both sides of the brain and in Old World monkeys label is mainly found ipsilaterally. Retinal fibers were also seen in the periamygdaloid region but never extended as far as piriform cortex. These results, in addition to previous studies in other mammalian orders, confirm that the basal telencephalon, and in particular the olfactory tubercle, constitutes a region of visual and olfactory convergence. This sensory integration may be related to photic and chemosensory modulation of reproductive physiology and behavior. © 1993 Wiley‐Liss, Inc.
Synapsin I Gene expression in the adult rat brain with comparative analysis of mRNA and protein in the hippocampus
Authors: Melloni Richard H. , Hemmendinger Lisa M. , Hamos James E. , Degennaro Louis J. 
Published: January 2005

AbstractSynapsin I is the best characterized member of a family of neuron‐specific phosphoproteins thought to be involved in the regulation of neurotransmitter release. In this report, we present the first extensive in situ hybridization study detailing the regional and cellular distribution of synapsin I mRNA in the adult rat brain. Both the regional distribution and relative levels of synapsin I mRNA established by in situ hybridization were confirmed by RNA blot analysis. Our data demonstrate the widespread yet regionally variable expression of synapsin I mRNA throughout the adult rat brain. The greatest abundance of synapsin I mRNA was found in the pyramidal neurons of the CA3 and CA4 fields of the hippocampus, and in the mitral and internal granular cell layers of the olfactory bulb. Other areas abundant in synapsin I mRNA were the layer II neurons of the piriform cortex and layer II and V neurons of the entorhinal cortex, the granule cell neurons of the dentate gyrus, the pyramidal neurons of hippocampal fields CA1 and CA2, and the cells of the parasubiculum. In general, the pattern of expression of synapsin I mRNA paralleled those encoding other synaptic terminal‐specific proteins, such as synaptophysin, VAMP‐2, and SNAP‐25, with noteworthy exceptions. To determine specificall how synapsin I mRNA levels are related to levels of synapsin I protein, we examined in detail the local distribution patterns of both synapsin I mRNA and protein in the rat hippocampus. These data revealed differential levels of expression of synapsin I mRNA and protein within defined synaptic circuits of the rat hippocampus. © 1993 Wiley‐Liss, Inc.
Two visual systems in one brain: Neuropils serving the principal eyes of the spider Cupiennius salei
Authors: Strausfeld Nicholas J. , Weltzien Peter , Barth Friedrich G. 
Published: January 2005

AbstractPrincipal (anterior median) eyes of the wandering spider Cupiennius are served by three successive neuropils, the organization of which is distinct from those serving secondary eyes. Photoreceptors terminate in the first optic neuropil amongst second order neurons with overlapping dendritic fields. Second order neurons terminate at various depths in anterior median eye medulla where they are visited by bush‐like dendritic trees of third order projection neurons. These supply tracts which extend into the “central body.” This crescent‐shaped neuropil lies midsagittally in the rear of the brain near its dorsal surface. It is organized into columns and it supplies both columnar and tangential efferents to other brain centers. The supply to and organization of the “central body” neuropil is reminiscent of retinotopic neuropils supplying the lobula of insects. Channels to the “central body” comprise one of two concurrent visual pathways, the other provided by the secondary eyes supplying the “mushroom body.” We suggest that principal eye pathways may be involved in form and texture perception whereas secondary eyes detect motion, as is known for jumping spiders. Our data do not support Hanström's classical view that the “central body” is specifically associated with web‐building, nor that it is homologous to its namesake in insect brains. © 1993 Wiley‐Liss, Inc.
Physiological properties and morphological characteristics of cutaneous and mucosal mechanical nociceptive neurons with A‐δ peripheral axons in the trigeminal ganglia of crotaline snakes
Authors: Liang Yun‐Fei , Terashima Shin‐Ichi 
Published: January 2005

AbstractPrimary A‐δ nociceptive neurons in the trigeminal ganglia of immobilized crotaline snakes were examined by intrasomal recording and injection of horseradish peroxidase in vivo. Thirty‐four neurons supplying the oral mucosa or facial skin were identified as A‐δ nociceptive neurons which responded exclusively to noxious mechanical stimuli and had a peripheral conduction velocity ranging from 2.6 to 15.4 m/s. These neurons were subdivided into a fast‐conducting type (FC‐type) and a slowly conducting type (SC‐type). Neurons of both types had a receptive field limited to a single spot which responded to pin prick stimulus with a threshold of more than 5 g. The FC‐type neurons had a narrow spike followed by a shorter after‐hyperpolarization. In contrast, SC‐type neurons exhibited a broad spike with a hump on the falling phase and a longer after‐hyperpolarization. The diameters of the stem, central and peripheral axons of the FC‐type neurons were significantly thicker than those of the SC‐type neurons, but there was no statistical difference in the soma size of the two types. Central axons of both types of neurons were thinner than their stem and peripheral axons. Dichotomizing fibers of peripheral axons were observed within the ganglion on 3 neurons. Central axons of the FC‐type neurons terminated ipsilaterally in the nucleus principalis, the subnucleus oralis, interpolaris and caudalis and the interstitial nucleus, whereas those of the SC‐type neurons generally projected only to the caudal half of the subnucleus interpolaris, subnucleus caudalis and interstitial nucleus ipsilaterally. The present data showed for the first time the physiological and morphological heterogeneity of the primary trigeminal A‐δ nociceptive neurons and revealed that the trigeminal nucleus principalis and all the subdivisions of the trigeminal descending nucleus are involved in nociception as relay nuclei, but the subnucleus caudalis and the caudal half subnucleus interpolaris are the essential relay sites of the primary nociceptive afferents supplying the oral mucosa and facial skin. The interstitial nucleus also appears to play an important role in orofacial nociception. © 1993 Wiley‐Liss, Inc.
A nonrandom interneuronal pattern in the developing frog spinal cord
Authors: Heathcote R. David , Chen Aileen 
Published: January 2005

AbstractIn the developing spinal cord of the frog, Xenopus laevis, a population of interneurons assumes a pattern that represents a previously undescribed level of organization. Glyoxylic acid treatment and immunocytochemistry show that the neurons contain catecholamines and their synthetic enzyme, tyrosine hydroxylase. Cells are located within the ependymal layer of the floor plate region of the larval spinal cord. The cells have several processes including a long one that projects toward the brain without fasciculating with other labeled processes. In addition, the cytoplasm of the catecholaminergic cells extends into the central canal, showing that they are a population of cerebrospinal fluid‐contacting neurons.The spatial domain of catecholaminergic neurons starts abruptly at the boundary between the hindbrain and spinal cord and continues to the tip of the tail. The neurons occupy two longitudinal columns within the sheet of floor plate cells, which includes cells that do not exhibit the catecholaminergic phenotype. Unlabeled cells are intercalated between catecholaminergic cells in each column, giving the labeled cells the appearance of being spaced along the length of the spinal cord. This general arrangement is evident at the time of hatching. Spatial analysis showed that the position of cells along a column is not random. The nonrandom behavior is due to cells being excluded from the area immediately surrounding other catecholaminergic cells. Further analysis showed that the cellular pattern lacks segmental or other periodic repeats. Ultimately, the location of a cell within a column depends upon the position of its closest catecholaminergic neighbor. © 1993 Wiley‐Liss, Inc.
Principal neurons as local circuit neurons in the rat superior cervical ganglion: The synaptology of the neuronal processes revealed by intracellular injection of biocytin
Authors: Kawai Yoshinori , Tamai Yasuhiko , Senba Emiko 
Published: January 2005

AbstractTo analyze the local circuitry of the sympathetic ganglion, the synaptic relations of the neuronal processes of the principal neurons in the rat superior cervical ganglion were investigated by correlated light and electron microscopy combined with intracellular injection of biocytin. Intracellular iontophoresis of biocytin followed by avidin‐biotinylated horseradish peroxidase cytochemistry allowed complete visualization of the neuronal processes of the principal neurons. The stained principal neurons have a single process (axon), which leaves the ganglion, and several intraganglionic processes (dendrites), some of which show specific terminal arborizations. Some terminals of the dendritic collaterals formed pericellular plexuses or intercellular glomerular plexuses. Electron microscopically, the dendrites and their collaterals contain numerous small vesicles. Synaptic membrane specializations were observed between the stained dendritic collaterals and unlabeled neurites. These may be both preganglionic axon terminals and processes of principal neurons. The likely direction of neurotransmission often could not be determined because of the bidirectional synaptic structures. Our findings show that the dendritic collaterals of principal neurons appear to make both post‐ and presynaptic contacts with both the principal neurons and the preganglionic axons. It is suggested that the principal neurons might participate in local circuits involving not only preganglionic axons but also neighboring principal neurons. © 1993 Wiley‐Liss, Inc.
OFF‐alpha and OFF‐beta ganglion cells in cat retina. I: Intracellular electrophysiology and HRP stains
Authors: Nelson Ralph , Kolb Helga , Freed Michael A. 
Published: January 2005

AbstractSix OFF‐alpha ganglion cells and a single OFF‐beta ganglion cell were penetrated with intracellular microelectodes and marked with horseradish peroxidase (HRP) in a perfused cat eyecup. Gaussian center radii (Rc) ranging from 40 to 217 μm were measured for receptive fields mapped with slits, values in agreement with previous extracellular reports. ON and OFF response components revealed nearly identical Rc's and center locations. Although Gaussian diameters (2Rc) were about 80% of dendritic field diameters overall, in this sample dendritic and receptive fields were not well correlated. Spatial tuning of ganglion cells was evidenced in peaked amplitude‐vs.‐width functions, fit by difference‐of‐Guassians models. Such plots yielded Rc values about 40% less than position‐vs amplitude plots. Rs values for surrounds ranged from 200 to 1,700 μm.Rod and cone signals were investigated with flicker. Rod flicker signals in OFF‐alpha cells were larger and of shorter latency than in either horizontal or AII amacrine cells. Cone flicker signals were also short in latency, with an ON response time constant of 9 msec, and an OFF response time constant of 3 msec. The OFF‐alpha rod‐cone transition involved a latency increase of 20–30 msec.The spontaneous and light‐evoked impulse rates of OFF‐alpha responses varied linearly with extrinsic current, but the amplitude of ON hyperpolarization was little affected. After injection of staining current, the OFF‐beta cell transiently depolarized at ON, suggestive of ON inhibition with reversed chloride gradient, a result not seen in OFF‐alpha responses.Events (peaked, depolarizing voltage fluctuations) of high, low, and intermediate amplitudes were studied in OFF‐alpha responses. High amplitude events (impulses), were OFF‐correlated with the stimulus, and exhibited mean rise times (transit time from 25 to 75% of peak amplitude) from 255 to 392 μsec. Intermediate level events (presumed synaptic origin) were also OFF correlated and had longer rise times (325 μsec to 1.56 msec). Low level events (234–685 μsec) revealed either ON, ON/OFF, or no stimulus correlation. Published in 1993 Wiley‐Liss, Inc.
Morphology of neurons in the thalamic reticular nucleus (TRN) of mammals as revealed by intracellular injections into fixed brain slices
Authors: Lübke J. 
Published: January 2005

AbstractI have investigated the morphology of neurons in the thalamic reticular nucleus (TRN) by means of intracellular injections in fixed tissue in order to study whether neurons in visual (dorsocaudal part), somatosensory (intermediate part), or limbic/motor (rostral part) sectors in the rat, rabbit, and cat differ morphologically in relation to their different sensory cortical or thalamic inputs. In addition, I have compared the different mammalian species to ask whether there is a morphological difference of TRN neurons according to reported differences in the intrinsic thalamic organisation, for example, due to the presence of GABAergic local circuit neurons in the majority of thalamic nuclei in the cat and the lack of those neurons in most of the rat thalamic nuclei, and presynaptic dendrites in the cat but not in the rat. In all animals investigated so far, neurons in the caudal (visual) and intermediate (somatosensory) part of the TRN have an elongated dendritic morphology in all three species, but some neurons in the rostral part, in particular in dorsal sections, have a distinctive multipolar morphology. Neurons have round, ovoid, or elongated somata ranging in area between 150 and 860 μm2. In general 4–8 first order dendrites emerge directly from the two poles of the soma or from a thick stem segment. Most of the dendrites then run parallel to the borders of the nucleus extending for relatively long distances, up to 450 μm, but remain inside the border of the nucleus. Only a few (1–3) dendrites could be observed to run perpendicular to the border of the nucleus and generally only for a short distance (20–70 μm). Some of the smooth first order dendrites give rise to second order dendrites (up to 200 μm in length), which then branch into short (15–70 μm) third order dendrites. Dendritic spines and varicosities, spine‐like protusions and/or hair‐like processes are mainly found on second and third order dendrites. Surprisingly, the shape, arrangement, and the size of the dendritic field are not strictly related to the shape and size of the nucleus. In mammalian species with a comparatively narrow TRN (rat and cat) the dendritic field size was similar to that in the rabbit with a broad TRN. There was considerable variability in dendritic morphology in the caudal and intermediate parts of TRN. However, in contrast to two recent studies in the rat TRN I have found no obvious basis for classification of neurons in the mammalian TRN according to dendritic morphology. In addition, there seems to be no difference in neuronal morphology of TRN neurons in relation to different intrinsic thalamic organisation within or between species. © 1993 Wiley‐Liss, Inc.
Heterogeneity and selectivity of the degeneration of cholinergic neurons in the basal forebrain of patients with Alzheimer's disease
Authors: Lehéricy Stéphane , Hirsch Étienne C. , Cervera‐Piérot Pascale , Hersh Louis B. , Bakchine Serge , Piette François , Duyckaerts Charles , Hauw Jean‐Jacques , Javoy‐Agid France , Agid Yves 
Published: January 2005

AbstractCholinergic neurons were studied by immunohistochemistry, with an antiserum against choline acetyltransferase (ChAT), in the basal forebrain (Ch1 to Ch4) of four patients with Alzheimer's disease (AD) and four control subjects. ChAT‐positive cell bodies were mapped and counted in Ch1 (medial septal nucleus), Ch2 (vertical nucleus of the diagonal band), Ch3 (horizontal nucleus of the diagonal band) and Ch4 (nucleus basalis of Meynert). Compared to controls, the number of cholinergic neurons in AD patients was reduced by 50% on average. The interindividual variations in cholinergic cell loss were high, neuronal loss ranging from moderate (27%) to severe (63%). Despite the small number of brains studied, a significant correlation was found between the cholinergic cell loss and the degree of intellectual impairment. To determine the selectivity of cholinergic neuronal loss in the basal forebrain of AD patients, NPY‐immunoreactive neurons were also investigated. The number of NPY‐positive cell bodies was the same in controls and AD patients. The results (1) confirm cholinergic neuron degeneration in the basal forebrain in AD and the relative sparing of these neurons in some patients, (2) indicate that degneration of cholinergic neurons in the basal forebrain contributes to intellectual decline, and (3) show that, in AD, such cholinergic cell loss is selective, since NPY‐positive neurons are preserved in the basal forebrain.
Chiasmatic course of temporal retinal axons in the developing ferret
Authors: Baker Gary E. , Reese Benjamin E. 
Published: January 2005

AbstractRecent studies on the distribution of optic axons in the mature visual pathways, as well as on the genesis of their ganglion cells of origin, suggest that the time of axonal arrival at the optic chiasm determines the side of the brain to which a temporal retinal axon will project. The present study has examined this issue directly in fetal ferrets, by determining the projection of the temporal retina at different developmental stages. Fetuses of known gestational age were fixed with paraformaldehyde and subsequently implanted with crystals of the carbocyanine dye, DiI, into eithe the temporal retina, or into one optic tract. The lipophilic diffusion of the dye within the plasma membrane of the axons revealed the course of temporal retinal fibers through the fetal chiasm, as well as the distribution of ganglion cells across the two retinae projecting to one optic tract.During early fetal stages, the temporal retina extends axons preferentially into the ipsilateral optic tract: the early retinal projection shows a classical partial decussation pattern. During later fetal stages, temporal retinal axons can be traced into both optic tracts, and the distribution of cells with crossed and uncrossed optic axons in the temporal retina is overlapping. These results indicate that the mature decussation patterns of retinal ganglion cell classes are not primarily the consequence of regressive phenomena such as cell death; rather, they are formed as axons navigate the chiasmatic region during development. The differences in decussation pattern between cell classes arise from the fact that the mechanisms producing the segregation of nasal and temporal retinal axons at the chiasm must change as development proceeds.