bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensory properties and afferents of the N. dorsolateralis posterior thalami of the pigeon
Authors: Korzeniewska Ewa , Güntürkün Onur 
Published: January 2005

AbstractAccording to previous studies, the avian n. dorsolateralis posterior thalami (DLP) receives visual and somatosensory afferents. While some authors (e. g., Gamlin and Cohen: J. Comp. Neurol. 250:296–310, '86) proposed a distinction between a visual caudal (DLPc) and a somatosensory rostral (DLPr) part, other authors (e. g., Wild: Brain Res. 412:205–223, '87) could not confirm such a differentiation. The aim of the present experiment was to study with physiological and anatomical methods the proposed parcellation of the DLP into various components dealing with different modalities.The physiological properties of the DLP of the pigeon were analysed with extracellular single unit recordings. With the same approach, neurons of the n. dorsalis intermedius ventralis anterior (DIVA), a somatosensory relay nucleus in the dorsal thalamus, were also analysed. The afferents of the DLP were studied by using anatomical tract tracing techniques with retrograde and anterograde tracers. The sensory properties of DLP cells revealed that somatosensory, visual, and auditory modalities affect the neuronal firing frequency in this nucleus. All three modalities were present throughout the full caudorostral extent of the DLP. Cells recorded in DIVA responded nearly exclusively to somatosensory stimulation. Unlike the DLP, single units in DIVA generally had smaller receptive fields encompassing only one extremity.The analysis of afferent connections of the DLP by using injections of retrograde and anterograde tracers (HRP, WGA‐HRP, Fast Blue, and Rhodamine‐β‐isothiocyanate) demonstrated extensive projections from the nuclei gracilis et cuneatus (GC) and more sparse projections from the nucleus tractus descendens trigemini (TTD), and the nucleus cuneatus externus (CE). Brainstem afferents of the DLP came from different vestibular nuclei, various areas of the brainstem reticular formation, and the optic tectum. Prosencephalic afferents originated in the n. posteroventralis thalami (PV), the n. ventromedialis posterior thalami (VMP), the n. dorsalis intermedius ventralis anterior (DIVA), and the nucleus reticularis superior pars dorsalis and ventralis (RSd and RSv). Telencephalic afferents of the DLP came from the hyperstriatum accessorium (HA) and a group of cells at the borderline between the hyperstriatum intercalatus superior (HIS) and the hyperstriatum dorsale (HD).The somatosensory afferents of the DLP probably originate from the GC, TTD, and CE, whereas it is likely that the visual input is mediated by the optic tectum. The anatomical source for the acoustic input is unclear. The very long latencies of auditory DLP neurons make it likely that the acoustic input originates at least partly in the reticular formation. The sensory properties and the organization of afferents suggest a general similarity of the DLP to the n. ventromedialis thalami of teleosts and the posterior complex of nuclei of mammals.
Sources of neostriatal cholecystokinin in the cat
Authors: Adams Catherine E. , Fisher Robin S. 
Published: January 2005

AbstractThe objective of this study was to determine the sources of cholecystokinin within the neostriatum of the cat. Cholecystokinin‐immunoreactive cells and fibers were detected by means of the peroxidase antiperoxidase immunohistochemical technique. This method was combined with intrastriatal injections of the retrograde marker horseradish peroxidase conjugated with wheatgerm agglutinin to survey the possible afferent sources of cholecystokinin to the feline neostriatum. Intrinsic, apparently aspiny cholecystokinin‐immunoreactive neurons organized in a pericapsular pattern were found within both the caudate and putamen of the cat. In addition, both thalamostriatal and mesostriatal projections containing cholecystokinin were observed. These results indicate that cholecystokinin within the neostriatum of the cat arises from both intrinsic and extrinsic sites.
Numbers of neurons and glia in mature rat somatosensory cortex: Effects of prenatal exposure to ethanol
Authors: Miller Michael W. , Potempa Gregory 
Published: January 2005

AbstractStereological methods were used to examine the consequences of prenatal exposure to ethanol on the structure of area 3, primary somatosensory cortex, of the mature hooded rat. Pregnant rats were fed a liquid diet containing 6.7% (v/v) ethanol (Et), pairfed an isocaloric liquid control diet (Ct), or fed a diet of chow and water (Ch). Cresyl violet‐stained sections of 3‐month‐old pups were examined. The corrected mean size of the cell bodies of neurons in layers other than layer V was significantly smaller in the Ettreated rats; conversely, the mean somatic size of glia in each layer was significantly larger in the Ettreated rats. The laminar cell packing density for neurons and glia, however, was similar in rats from both treatment groups. The overall volume of area 3 and the volume of individual layers were about 33% smaller in Et‐treated rats than in the pair‐fed controls. Thus, the estimated total number of neurons in Et‐treated rats (1.79*106) was significantly fewer than in Chtreated rats (2.77*106) and in Ct‐treated rats (2.66*106). The total number of glia also was about 30% fewer in Et‐treated rats than in the controls. Not all layers were affected equivalently. The space occupied by the neuropil was significantly greater in Et‐treated rats, but only in layers II/III, IV, and VI; hence, the cell body/neuropil ratio in these layers was less in Et‐treated rats than in the controls. Therefore, microcephaly caused by prenatal exposure to ethanol results not only from a miniaturization of the brain, but also from a permanent abnormal organization of cerebral cortex.
Cortical projection patterns of the medial septum‐diagonal band complex
Authors: Gaykema Ronald P. A. , Luiten Paul G. M. , Nyakas Csaba , Traber Jörg 
Published: January 2005

AbstractA detailed analysis of the cortical projections of the medial septum‐diagonal band (MS/DB) complex was carried out by means of anterograde transport of Phaseolus vulgaris leucoagglutinin (PHA‐L). The tracer was injected iontophoretically into cell groups of the medial septum (MS) and the vertical and horizontal limbs of the diagonal band of Broca (VDB and HDB), and sections were processed immunohistochemically for the intra‐axonally transported PHA‐L. The labeled efferents showed remarkable differences in regional distribution in the cortical mantle dependent on the position of the injection site in the MS/DB complex, revealing a topographic organization of the MS/DB‐cortical projection. In brief, the lateral and intermediate aspects of the HDB, also referred to as the magnocellular preoptic area, predominantly project to the olfactory nuclei and the lateral entorhinal cortex. The medial part of the HDB and adjacent caudal (angular) part of the VDB are characterized by widespread, abundant projections to medial mesolimbic, occipital, and lateral entorhinal cortices, olfactory bulb, and dorsal aspects of the subicular and hippocampal areas. Projections from the rostromedial part of the VDB and from the MS are preponderantly aimed at the entire hippocampal and retrohippocampal regions and to a lesser degree at the medial mesolimbic cortex. Furthermore, the MS projections are subject to a clear mediolateral topographic arrangement, such that the lateral MS predominantly projects to the ventral/temporal aspects of the subicular complex and hippocampus and to the medial portion of the entorhinal cortex, whereas more medially located cells in the MS innervate more septal/dorsal parts of the hippocampal and subicular areas and more lateral parts of the entorhinal cortex. PHA‐L filled axons have been observed to course through a number of pathways, i. e., the fimbria‐fornix system, supracallosal stria, olfactory peduncle, and lateral piriform route (the latter two mainly by the HDB and caudal VDB). Generally, labeled projections were distributed throughout all cortical layers, although clear patterns of lamination were present in several target areas. The richly branching fibers were abundantly provided with both “boutons en passant” and terminal boutons. Both distribution and morphology of the labeled basal forebrain efferents in the prefrontal, cingulate, and occipital cortices closely resemble the distribution and morphology of the cholinergic innervation as revealed by immunohistochemical demonstration of choline acetyltransferase. In contrast, the labeled projections to the olfactory, hippocampal, subicular, and entorhinal areas showed a heterogeneous morphology. Here, the distribution of only the thin varicose projections resembled the distribution of cholinergic fibers.
Innervation of a lizard auditory organ having gap junctions between most hair cells: A serial transmission electron microscopy study
Authors: Miller Malcolm R. , Beck Janet 
Published: January 2005

AbstractTwo apical unidirectional and 16 basal bidirectional papillar hair cells of the yucca night lizard, Xantusia vigilis, were serially sectioned for transmission electron microscopy (TEM) to determine the pattern of hair cell innervation. The 16 bidirectional hair cells (central group) were sectioned across the entire width of the papilla and consisted of four complete hair cells in each of the first three rows and the upper (or neural) half of the four hair cells in the fourth or last row. Both hair cell types were nonexclusively innervated, i.e., each afferent nerve fiber innervated two or more hair cells. The apical unidirectional hair cells were innervated by six or seven different afferent nerve fibers and five or six efferent fibers. The afferent nerve fibers made an average of 52.5 synapses/hair cell. In the central group of 16 bidirectional hair cells, 25 different afferent nerve fibers innervated an average of 4.5 hair cells. The average number of hair cells innervated by the eight afferent nerve fibers limited to the central group was 5.4. An unusual finding was the presence of gap junctions directly interconnecting more than half the hair cells in both papillar segments. In the bidirectional hair cell region, it was possible to count the number of gap junctions between 24 contiguous hair cells. The average number of gap junctions was four per hair cell, and all bidirectional hair cell were either directly or indirectly interconnected by gap junctions. The possible function of a nonexclusive type of hair cell innervation and the presence of large numbers of gap junctions are discussed.
Topographic organization of the ventral striatal efferent projections in the rhesus monkey: An anterograde tracing study
Authors: Haber S. N. , Lynd E. , Klein C. , Groenewegen H. J. 
Published: January 2005

AbstractThe ventral striatum is considered to be that portion of the striatum associated with the limbic system by virtue of its afferent connections from allocortical and mesolimbic areas as well as from the amygdala. The efferent projections from this striatal region in the primate were traced by using 3H aminoacids and Phaseolus vulgaris‐leucoagglutinin (PHA‐L). Particular attention was paid to the topographic organization of terminal fields in the globus pallidus and substantia nigra, the projections to non‐extrapyramidal areas, the relationship between projections from the nucleus accumbens and the other parts of the ventral striatum, and the comparison between ventral and dorsal striatal projections.This study demonstrates that in monkeys a circumscribed region of the globus pallidus receives topographically organized efferent fibers from the ventral striatum. The ventral striatal fibers terminate in the ventral pallidum, the subcommissural part of the globus pallidus, the rostral pole of the external segment, and the rostromedial portion of the internal segment. The more central and caudal portions of the globus pallidus do not receive this input. This striatal output appears to remain segregated from the dorsal striatal efferent projections to pallidal structures.Fibers from the ventral striatum projecting to the substantia nigra are not as confined to a specific region as those projecting to the globus pallidus. Although the densest terminal fields occur in the medial portion, numerous fibers also extend laterally to innervate the dorsal stratum of dopaminergic neurons of the substantia nigra and the retrorubral area. Furthermore, they project throughout the rostral‐caudal extent of the substantia nigra. Projections from the medial part of the ventral striatum reach the more caudally located pedunculopontine tegmental nucleus. Thus unlike the above described terminals in the globus pallidus, the ventral striatum project widely throughout the substantia nigra, a fact that indicates that they may contribute to the integration between limbic and other output systems of the striatum.Finally, the ventral striatum projects to non‐extrapyramidal regions including the bed nucleus of the stria terminals, the nucleus basalis magnocellularis, the lateral hypothalamus, and the medial thalamus.
Immunolabelling by a newt retinal pigment epithelium antibody during retinal development and regeneration
Authors: Klein Lisa R. , MacLeish P. R. , Wiesel Torsten N. 
Published: January 2005

AbstractThe binding of RPE‐1, a mouse monoclonal antibody selective for newt retinal pigment epithelium, was followed in eyes undergoing embryonic developemnt and retinal regeneration. Using the indirect immunofluorescence technique on frozen sections, we observed bright and continuous labelling exclusively in the retinal pigment epithelium (RPE) of normal adult newts, but labelling became diminished near the ora serrata region and stopped abruptly at the ciliary margin. During development, labelling was not detected in the retinal pigment epithelium (RPE) until the formation of photoreceptor outer segments and was not observed in any other ocular tissue. There was no correlation between the appearance of pigment in retinal pigment epithelial cells and their labelling with the RPE‐1 antibody. Furthermore, albino salamander embryos showed the same pattern of labelling with RPE‐1 as that seen in age‐matched pigmented animals. During retinal regeneration, RPE cells were labelled less intensely, but heavy labelling was observed in the newly formed retinal cells. With time, labelling in regenerated retina receded, so that by the end of regeneration, labelling by RPE‐1 was once more restricted to the RPE cells. The identification of RPE‐1 as a marker for postmitotic retinal neurons about to undergo differentiation provides a promising approach for further studies of regeneration with the help of molecular tools.
Neuropeptides and catecholamines in efferent projections of the nuclei of the solitary tract in the rat
Authors: Riche D. , De Pommery J. , Menetrey D. 
Published: January 2005

AbstractThis study focuses on the involvment of catecholamines and nine different peptides in efferents of the nucleus of the solitary tract to the central nucleus of the amygdala, the bed nucleus of the stria terminalis, and different parabrachial and hypothalamic nuclei in the rat. A double‐labeling technique was used that combines a protein‐gold complex as the retrograde tracer with immunohistochemistry.Catecholaminergic projection neurons were the most numerous type observed and projected mainly ipsilaterally to all targets studied. Most projections arose from areas overlying the dorsal motor nucleus, mainly the medial nucleus. Neurons synthesizing somatostatin, met‐enkephalin‐Arg‐Gly‐Leu, dynorphin B, neuropeptide Y, and neurotensin projected to all structures examined. Somatostatin and enkephalin immunoreactive projection cells were the most numerous. They were located in close proximity to each other, including all subnuclei immediately surrounding the solitary tract, bilaterally. Most dynorphin and neuropeptide Y immunoreactive projection cells were found rostral to that of enkephalinergic and somatostatinergic projections, and mainly in the ipsilateral medial nucleus. Neurotensinergic projections were sparse and from dorsal and dorsolateral nuclei.Substance P and cholecystokinin contribute to parabrachial afferents. The location of substance P immunoreactive projection cells closely resembled that of enkephalinergic and somatostatinergic projections. Projecting cholecystokinin immunoreactive cells were observed in dorsolateral nucleus. Bombesin immunoreactive cells in dorsal nucleus projected to either the parabrachial or hypothalamic nuclei. No vasoactive intestinal polypeptide‐containing cells were detected.Thus, most catecholaminergic and neuropeptidergic efferents originated from different populations of cells. It is proposed that catecholaminergic neurons constitute the bulk of solitary efferents and that they may contribute to autonomic neurotransmission. Peptidergic neurons mainly form other subgroups of projections and may play a role in modulating the physiological state of the target nuclei.
Distribution of locus coeruleus axons within the rat brainstem demonstrated by Phaseolus vulgaris leucoagglutinin anterograde tracing in combination with dopamine‐β‐hydroxylase immunofluorescence
Authors: Fritschy Jean‐Marc , Grzanna Reinhard 
Published: January 2005

AbstractProjections of the locus coeruleus (LC) to the midbrain and hindbrain were analyzed by anterograde transport of the lectin Phaseolus vulgaris leucoagglutinin (PHA‐L). Following iontophoretic application of PHA‐L into the LC, the distribution of labeled axons was analyzed in sections processed for the immunoperoxidase method and in sections processed for double‐immuno‐fluorescence staining using antibodies to PHA‐L and to dopamine‐β‐hydroxylase. This combined staining approach proved to be necessary for the unequivocal identification of LC axons in the brainstem since all injections labeled many non‐noradrenergic axons whose distribution was different from that of LC fibers. The major new finding of the present study was the observation that large territories of the brainstem that receive a dense noradrenergic input are very sparsely innervated by the LC. Numerous labeled LC axons were observed in somatic afferent nuclei, tectum, pontine nuclei, interpeduncular nucleus, and inferior olivary complex. In contrast, very few labeled fibers were observed in autonomic and motor nuclei, and throughout the brainstem reticular formation, including raphe nuclei. Our data show that the distribution of LC axons in the brainstem is far less prominent than the projections of this nucleus to the forebrain and spinal cord. Our findings suggest that the dense NA projections to the core of the brainstem originate principally in non‐LC NA neurons. On the basis of the present anatomical findings, a prominent role of the LC in motor and integrative functions of the brainstem appears unlikely.
Cholera toxin B‐gold, a retrograde tracer that can be used in light and electron microscopic immunocytochemical studies
Authors: Llewellyn‐Smith I. J. , Minson J. B. , Wright A. P. , Hodgson A. J. 
Published: January 2005

AbstractThe purpose of this study was to test whether a new retrograde tracer, the B subunit of cholera toxin conjugated to colloidal gold particles (Ctb‐gold), was taken up and transported by neurons in the central nervous system of the rat. Retrograde transport of CTB‐gold was assessed from axon terminals, from damaged nerve fibers, and from axons of passage. For light microscopy, CTB‐gold was visualized by silver intensification; for electron microscopy, sections were silver‐intensified with or without subsequent gold toning.Retrogradely transported CTB‐gold was detected in neurons after survival times of 12 hours to 42 days and appeared as black punctate deposits in perikarya and proximal dendrites at the light microscope level. Ultrastructurally, the deposits were usually associated with lysosomes.Injections of CTB‐gold into the caudal ventrolateral medulla or into the lateral horn of the spinal cord gave small well‐defined injection sites and resulted in retrograde labelling in medullary neurons in the same locations as similarly placed injections of wheat germ agglutinin‐horseradish peroxidase. When injected into the superior cervical ganglion, CTB‐gold was transported to nerve cell bodies in the spinal cord, but application of CTB‐gold to the cut cervical sympathetic trunk did not label neurons in the spinal cord. Injection of CTB‐gold into the nodose ganglion retrogradely labelled neurons in the dorsal motor nucleus of the vagus and the nucleus ambiguus. CTB‐gold was not transported anterogradely from injections sites within the medulla.Nerve fibers and cell bodies containing neuropeptides, monoamines, or neurotransmitter‐synthesizing enzymes were readily immunostained after silver intensification of retrogradely transported CTB‐gold. Immunoreactivity for neuropeptides and enzymes was also demonstrated ultrastructurally after silver intensification and gold toning.These results show that CTB‐gold is retrogradely transported from nerve terminals and fibers of passage but not from damaged axons. CTB‐gold gives well‐localized injection sites and persists in neurons for weeks. Transported CTB‐gold is easily visualized and its detection is compatible with light and electron microscopic immunocytochemistry. These properties make CTB‐gold a valuable tool for studying the connectivity and neurochemistry of path ways in the central nervous system.
Galanin‐like immunoreactivity within the primate basal forebrain: Differential staining patterns between humans and monkeys
Authors: Kordower Jeffrey H. , Mufson Elliott J. 
Published: January 2005

AbstractGalanin‐like immunoreactivity (GAL‐ir) was examined within the basal forebrain and adjacent regions of eight young adult New World monkeys (Cebus apella), one aged Old World monkey (Macaca mullata), and eight humans without clinical or pathological evidence of neurological disease. All monkeys demonstrated similar patterns of immunoreactive profiles characterized by a continuum of GAL‐in magnocellular neurons located within the medial septum, diagonal band nuclei, and nucleus basalis. Colocalization experiments revealed that most (>90%) of GAL‐ir basal forebrain neurons also expressed the receptor for nerve growth factor (NGFR), an excellent marker for primate cholinergic basal forebrain neurons. A few smaller parvicellular GAL‐ir neurons were also observed within the monkey basal forebrain. In contrast, identical cytochemical experiments revealed that virtually none of the magnocellular neurons within the basal forebrain of humans were GAL‐ir. Rather, a network of GAL‐containing fibers and terminal‐like profiles were observed encompassing the magnocellular cholinergic neurons in humans. This immunohistochemical species difference does not appear to be mediated by procedural or technical factors since human brains contained numerous GAL‐ir perikarya and fibers within adjacent regions including the bed nucleus of the stria terminalis and medial hypothalamus. These data demonstrate that there is a prominent phylogenetic transformation in primates with respect to the processing of GAL‐mediated information. This species difference potentially relates to the severe basal forebrain degeneration reported in human dementias and illustrates the possible need for a reevaluation of the use of monkeys as an animal model of human basal forebrain‐related cognitive dysfunction.