bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postnatal development of serotonin nerve fibers in the somatosensory cortex of mice studied by immunohistochemistry
Authors: Fujimiya Mineko , Kimura Hiroshi , Maeda Toshihiro 
Published: January 2005

AbstractPostnatal serotonin (5HT) innervation in the cerebral cortex of mice has been studied by 5HT immunohistochemistry. 5HT‐like immunoreactive (5HT‐LI) nerve fibers and terminals appeared to increase transiently, particularly in the somatosensory (Sm) cortex during early postnatal days. As pups grow, 5HT afferent inputs decreased rapidly to reach a similar pattern of distribution to that in adult animals. Since the transient increase was seen at a critical period (seventh postnatal day) for the differentiation of layer IV, it is suggested that increased 5HT concentrations might have an effect on thalamocortical inputs and/or cortical lamination of the developing brains.
Retinotopic organization within the cat's posterior suprasylvian sulcus and gyrus
Authors: Updyke B. V. 
Published: January 2005

AbstractThe organization of extrastriate visual areas of the cat's posterior suprasylvian sulcus and gyrus was studied with electrophysiological mapping methods. Analysis of retinotopic organization confirmed the presence of dorsal lateral and ventral lateral suprasylvian (DLS, VLS) visual areas (Palmer et al., '78, J. Comp. Neurol. 177:237‐256) and demonstrated new features of organization. Areas DLS and VLS occupy the upper two‐thirds of the posterior suprasylvian sulcus, with DLS wholly confined to the upper bank and VLS straddling the sulcal fundus. Both areas contain a partial representation of the lower quadrant of the visual field. A narrow strip of visually responsive cortex (periauditory belt) was identified adjoining DLS on the posterior ectosylvian gyrus; its organization and extent were not explored in detail.The organization of the posterior suprasylvian areas (PS) (Updyke, '82, Soc Neurosci. Abst. 8:810) was explored in detail. Area PS lies inferior to areas VLS and 21b in the lower third of the posterior suprasylvian sulcus and gyrus, extending onto the fusiform gyrus. PS contains a partial representation of the lower quadrant of the visual field. It shares a representation of horizontal meridian with area 21b and a representation of central gaze with area VLS. Analysis of the PS/20 border region indicates that the representation of the lower quadrant periphery is common to the borders of PS, 20a, and 20b rather than lying internal to areas 20a and 20b as suggested by Tusa and Palmer ('80, J. Comp. Neurol. 193:147‐164).
Projections from the parabigeminal nucleus to the dorsal lateral geniculate nucleus in the tree shrew Tupaia glis
Authors: Hashikawa T. , Van Lieshout D. , Harting J. K. 
Published: January 2005

AbstractThe parabigeminal nucleus receives its major input from the superficial layers of the superior colliculus via the tectoparabigeminal projection. An extensive reciprocal parabigeminotectal pathway has also been observed. This close connectional association between the superficial gray and the parabigeminal nucleus is reflected in the collicularlike response characteristics of parabigemiml neurons (see Sherk: Brain Res. 145:375‐379, '78, J. Neurophysiol 42:1640‐1655, 1656‐1668, '79a,b, for review).Further documentation of the connectional relationship between the superior colliculus and the parabigeminal nucleus comes from the present data. Thus, our retrograde and anterograde transport findings reveal an extensive projection from the parabigeminal nucleus to layers 3 and 6 and several inter antinar zones of the contralateral dorsal lateral geniculate nucleus. These same layers and interlaminar zones receive tectogeniculate axons and have been shown to contain small cells that project to layers 1 and 3 of area 17.In addition to the distribution of parabigeminal axons to tectally innervated, small‐celled zones, considerable parabigeminal input also reaches layers 1 and 5 of the tree shrew lateral geniculate nucleus. Each of these layers is the ipsilaterally (i.e., retinal) innervated component of a matched pair (layers 1 and 2 are considered magnocellular, while 4 and 5 are parvicellular), and it has been shown that layer 1 projects to lamina IVa of area 17, while layer 5 projects to lamina IVB. When the total distribution of parabigeminogeniculate axons is considered, it is apparent that the cells of origin of each of the major (small‐celled, parvi‐ and magnocellular) geniculocortical channels receives parabigeminal input. Such an extensive distribution of parabigeminal axons within the lateral geniculate nucleus suggests that the information they convey might play an, important role in geniculocortical function(s).
Neuronal architecture in the rat central nucleus of the amygdala: A cytological, hodological, and immunocytochemical study
Authors: Cassell M. D. , Gray T. S. , Kiss J. Z. 
Published: January 2005

AbstractThe organization of neurons in the rat central nucleus of the amygdala (CNA) has been examined by using Nissl stain and immunocytochemical and retrograde tracing techniques. Four main subdivisions were identified on the basis of quantitative analyses of Nissl‐stained material: medial (CM), lateral (CL), lateral capsular (CLC), and ventral (CV). An intermediate subdivision (CI), previously described by McDonald ('82), was apparent only in animals that had HRP‐WGA injected into the bed nucleus of the stria terminalis. Large populations of neurotensin‐, corticotropin‐releasing factor (CRF)‐, and enkephalin‐immunoreactive neurons were present within the lateral divisions (mainly CL), although they were also seen within CM. Somatostatin‐immunoreactive neurons were distributed mainly within CL and CM. Within CL, neurotensin and enkephalin‐immunoreactive neurons were more numerous laterally whereas CRF and somatostatin‐immunoreactive neurons were more numerous medially. Substance P‐immunoreactive neurons were almost exclusively confined to CM. Only a few cholecystokin‐and vasoactive‐polypeptide‐immunoreactive neurons were seen in the CNA, and they were observed within CL, CV, and CM. The majority of neurons projecting to the dorsal medulla, hypothalamus, and ventral tegmental area were located within CM, although a significant number of cells were also seen within CL. Efferent projections to the bed nucleus of the stria terminalis were found to arise from neurons located within all subdivisions of the CNA. Thus, the distributional patterns of peptidergic and efferent neurons were not confined to individual cytoarchitectonically defined subdivisions of the CNA. Rather, the results suggest overlapping medial to the lateral trends. Comparisons with the results of previous studies indicate that peptidergic and afferent terminal distribution patterns are more restricted to individual cytoarchitectonically defined subregions of the CNA. These observations suggest that the detailed cytoarchitecture of the CNA more likely reflects the functional integration of afferents rather than the organization of the CNA output neurons.
Intraspinal transplantation of embyronic spinal cord tissue in neonatal and adult rats
Authors: Reier P. J. , Bregman B. S. , Wujek J. R. 
Published: January 2005

AbstractFetal rat spinal cord tissue was obtained on gestational day 14 (E14) and transplanted into 2–4‐mm‐long intraspinal cavities produced by partial spinal cord lesions in adult and neonatal rats. At regular post‐transplantation intervals, light and electron microscopy, autoradiographic demonstration of tritiated thymidine labelling, and immunocytochemical localization of glial fibrillary acidic protein (GFAP) were used to identify surviving donor tissues and to study their differentiation and extent of fusion with recipient spinal cords. In some experiments, wheat germ agglutinin‐conjugated horseradish peroxidase (WGA‐HRP) was also employed to examine whether neurons within the grafts projected axons into the host spinal cord and vice versa. Lastly, immunocytochemistry was used to determine whether any supraspinal serotoninergic (5‐HT) axons from the host extended into the transplants.Over 80% of the grafts survived in lesions of both the neonatal and adult rat spinal cord for periods of 1–16 months (duration of experiment), and considerable maturation of donor tissue was evidenced, which even included the appearance of some topographical features of the normal spinal cord. Many of the transplants extended the entire length of the lesion, and were often closely apposed to the injured surfaces of the recipient spinal cords without an intervening dense glial scar. At post‐transplantation intervals of 2–4 months, injection of WGA‐HRP into the host spinal cord (5 mm from the transplant in adult animals or as much as 20 mm in neonatal recipients) demonstrated retrogradely labelled neurons and anterogradely labelled axons in the grafts. Likewise, injecting WGA‐HRP into transplants in adult recipients resulted in labelling of neurons in adjacent segments of the host spinal cord; some labelled axons, derived from donor neurons, were also present in neighboring spinal gray matter. Finally, immunocytochemistry revealed 5‐HT‐like immunoreactive fibers in transplants that had been prelabelled with tritiated thymidine. These observations demonstrate the potential of embryonic spinal cord transplants to replace damaged intraspinal neuronal populations and to restore some degree of anatomical continuity between the isolated rostral and caudal stumps of the injured mammalian spinal cord.
Telencephalic ascending acousticolateral system in a teleost (sebastiscus marmoratus), with special reference to the fiber connections of the nucleus preglomerulosus
Authors: Murakami Takeshi , Fukuoka Toshio , Ito Hironobu 
Published: January 2005

AbstractAcousticolateral systems were examined by means of the horseradish peroxidase tracing method in a teleost (Sebastiscus marmoratus). The torus semicircularis projected bilaterally to the optic tectum, nucleus ventromedialis thalami of Schnitzlein ('62), and reticular formation; contralaterally to the torus semicircularis; and ipsilaterally to the nucleus preglomerulosus of Schnitzlein ('62) and the inferior olive. No topographic organization was detected between the torus semicircularis and the nucleus preglomerulosus. Ipsilateral inputs to the torus were from dorsal telencephalic areas (pars centralis, Dc; pars dorsalis, Dd; and the dorsal part of pars medialis, dDm) and the optic tectum. Contralateral inputs to the torus were from the torus semicircularis, a caudal part of the cerebellum; and a portion of the trigeminal complex. The torus also received bilateral input from the nucleus ventromedialis thalami, nucleus of lemniscus lateralis, nucleus medialis, anterior octaval nucleus, descending octaval nucleus, and the reticular formation. Retrogradely labeled cells in the octaval nuclei were seen predominantly subsequent to HRP injections in the medial torus, while cells in the nucleus medialis were retrogradely labeled following injections into the lateral torus. HRP injections into the nucleus preglomerulosus labeled cells in the superficial region of the torus, while injections into the nucleus ventromedialis thalami labeled cells in the deep region. The nucleus preglomerulosus received inputs bilaterally from the nucleus of the lemniscus lateralis and reticular formation and ipsilaterally from the dorsal telencephalic areas (Dc, Dd, and dDm) and the torus semicircularis. In turn the nucleus preglomeru'‐osus projected to Dd and Dm. Fibers arising in the nucleus ventromedialis thalami ended in Dc, Dd, Dm, and area ventralis pars supracommissuralis (Vs).Homology between the nucleus preglomerulosus and the central thalamic nucleus in amphibians, the nucleus reuniens in reptiles, the nucleus ovoidalis in birds, and the medial geniculate body in mammals is discussed.
Neuropeptide‐Fmrfamide‐Like immunoreactivity in drosophila: Development and distribution
Authors: White Kalpana , Hurteau Teresa , Punsal Patricia 
Published: January 2005

AbstractNeuropeptide‐FMRFamide‐like immunoreactivity was characterized in the fruit fly, Drosophila melanogaster. In the adult central nervous system, a stereotypic pattern of immunoreactive cell bodies and immunoreactive nerve processes and varicosities was observed, indicating a neurochemical role for FMRFamide‐like substance(s) in Drosophila. Localization of immunoreactivity in the central nervous system of early larval stage revealed that the majority of the prominent FMRFamide‐like immunoreactive neurons were already differentiated. The FMRFamide‐like immunoreactive neurons remain immunoreactive throughout postembryonic stage and persist in the adult central nervous system. In the larva, in addition to the central nervous system, FMRFamide‐like immunoreactivity was localized in the fibers innervating the ring gland, in the ganglion innervating the gut and in the gastric caeca.
Physiology and morphology of the lamina i spinomesencephalic projection
Authors: Hylden Janice L. K. , Hayashi D. R. Haruhide , Dubner Ronald , Bennett Gary J. 
Published: January 2005

AbstractWe have examined the physiological and morphological characteristics of spinal dorsal horn lamina I neurons with projections to the midbrain in the cat by combining physiological recording of neurons with the intracellular injection of HRP. Lamina I spinomesencephalic neurons were antidromically activated from the region that included the cuneiform nucleus and lateral periaqueductal gray at the intercollicular level. The majority of mesencephalic projection neurons (50 of 55) responded exclusively to noxious stimulation (nociceptive‐specific) of their peripheral receptive fields. Lamina I spinomesencephalic neurons were activated from both the ipsilateral and contralateral midbrain and had slow antidromic conduction velocities (1 to 18 m/second). We identified eight cells with projections to both the midbrain and the thalamus and eight cells that were antidromically activated only from the thalamus. Intracellular injection of HRP revealed that lamina I spinomesencephalic neurons were of diverse morphological types, but generally had extensive, rostrocaudally oriented, dendritic arbors confined to lamina I and the overlying white matter. Axons were observed on nine of the HRP‐filled spinomesencephalic neurons; five of the axons issued collateral branches. The morphological characteristics of these neurons did not appear to correlate with functional categories (i.e., wide‐dynamic‐range‐ or nociceptive‐specific‐type neurons). The large number of nociceptive‐specific neurons with projections to the midbrain and the interconnections of these midbrain sites with hypothalamic and limbic structures suggest that the lamina I spinomesencephalic pathway plays an important role in the autonomic and affective responses to pain.
Influence of reduced neuron pool on the magnitude of naturally occurring motor neuron death
Authors: Sohal G. S. , Stoney S. D. , Arumugam T. , Yamashita T. , Knox T. S. 
Published: January 2005

AbstractThe present investigation was undertaken to examine the role of peripheral competition in survival of motor neurons during development. A loss of approximately half of the trochlear motor neurons in duck and quail occurs during the course of normal embryogenesis. The number of motor neurons in the nucleus of quail prior to the onset of cell death is identical to the final number of survivors in the nucleus of duck embryos (about 1,300 neurons). In the present study competition at the peripheral target was decreased by reducing the number of trochlear motor neurons initially projecting to their target muscle. This was accomplished by substituting the midbrain of duck embryos with the same neural tissue from quail embryos. Midbrain transplantation was performed before motor axon outgrowth and normal cell death begin. The development of the motor neurons and their sole target of innervation, the superior oblique muscle, was examined by using a variety of techniques. The source of the grafted motor neurons and of a reduction in the size of the motor neuron pool was confirmed from histological sections and cell counts. The grafted motor neurons projected their axons into the appropriate peripheral target, which was determined by the use of HRP tracing techrique. Counts of muscle fibers, motor endplates, and acetylcholine receptors and measurement of total muscle protein indicated that the size of the superior oblique muscle in the chimera embryos was similar to that of the normal duck but significantly larger than the muscle in quail embryos. Electrophysiological observations indicated that the grafted trochlear motor neurons made functional connections with the superior oblique muscle. Counts of the trochlear motor neurons after the period of cell death indicated an average of 1,310 neurons in the nucleus of duck, 772 in quail, and 690 in the chimera embryos. The number of motor neurons in the chimera embryos is not significantly different from that in the normal quail. In other words, in spite of reduced peripheral competition trochlear motor neuron death of normal magnitude occurred. Lack of increased cell survival in our study suggests that trochlear motor neurons do not compete for survival at the peripheral target.
Projections to the superior temporal sulcus from the central and peripheral field representations of V1 and V2
Authors: Ungerleider Leslie G. , Desimone Robert 
Published: January 2005

AbstractIn a series of three studies, we have begun to explore the sequence of visual information processing along the pathway from striate cortex (V1), through MT, into the parietal lobe. In this first study, we sought to establish the relationships among MT, the heavily myelinated zone of the superiortemporal sulcus (STS), and the V1 and V2 projection fields in the STS.Autoradiographic material from seven hemispheres of six macaques injected with tritiated amino acids into either V1 or V2 was analyzed in detail, and the results were plotted onto two‐dimensional reconstructions of the STS. Autoradiographic material from eight additional macaques with V2 injections was also examined.The results indicate that the central visual field representations of both V1 and V2 project into the heavily myelinated zone in the lower bank and floor of the STS, confirming prior studies, whereas the far peripheral representations of both V1 and V2 project into the cortex medial to this zone on the upper bank of the sulcus. There is no evidence that this medial cortex is a separate area that receives projections from V1 and V2 in parallel with the projections these areas send to the heavily myelinated zone. Rather, there seems to be a single projection field of V1 and V2 whose central representation lies within the heavily myelinated zone and whose most peripheral representation lies medial to it.Because of the difference in myelination between the central and peripheral field representations as well as visuotopic anomalies between them, we retain the term “MT” for the heavily myelinated zone and apply the term “MTp” to the far peripheral projection zone. Both MT and MTp are required to process the complete outputs of V1 and V2 within the STS and thus should probably be regarded as two distinctive parts of a single visual area. The difference in myelination between MT and MTp suggests that there is a difference in visual processing between the central and peripheral visual fields. The average size of MT is estimated to be 62 mm2, and the average size of MT and MTp combined to be 76 mm2, which is consistent with estimates derived from several other studies.
Development of cell and fiber lamination in the mouse superior colliculus
Authors: Edwards M. A. , Caviness V. S. , Schneider G. E. 
Published: January 2005

AbstractThe emergence of laminar organization in the superior colliculus was investigated in the mouse with several anatomical methods, including tritiated‐thymidine autoradiography, Golgi impregnation, and general stains for cell bodies and for fibers. The sequence of neurogenesis, cell migration, and early morphological differentiation of neurons was shown to exhibit a discontinuity between the lower and upper divisions (i.e., between the deep and intermediate “gray” and “white” layers and the superficial “gray” and “white” layers). These events proceed in an inside‐out order within the lower division, but tho same events within the upper division commence in advance of the completion of this progression. Thus, peak generation times for layers of the lower division proceed from (embryonic day) E11 to E13 and for the upper division from E12 to E13. Cell migration, as monitored with tritiated‐thymidine labelling, reflects closely the pattern of cytogenesis. This is most clearly evident on E15 when a population of E11‐labelled cells is divided into superficial and deep layers (the strata superficiale and profundum–SS and SP) by the interposition of E13‐labelled cells at an intermediate level (stratum inter medium–SI). A contingent of the latter cells continue their migration and join their predecessors within the SS on E17, a time point when cell migrations are largely complete. Paralleling this sequence of arrival of neurons and the formation of three primary layers, both the time course of accumulation of fiber fascicles and the early morphological differentiation of neurons in the interval from E13 to E17 tends to proceed from SP to SS and from SS to SI. Thus, the transverse fiber system and large multipolar neurons of SP develop in advance of the longitudinal fiber system and vertically oriented neurons of SS, which in turn develop precociously with respect to the longitudinal fibers and medium‐sized multipolar neurons of SI. In contrast, later events of differentiation that underly a major radial growth and an architectonic sublamination of the primary strata proceed in a simpler inside‐out sequence from E17 to (postnatal day) P6. The major morphogenetic events underlying the establishment of statification in the colliculus appear to involve the operation of relatively independent programs of assembly for the two basic subdivisions. It is probable that selective cell‐cell interactions contribute to the delivery of concurrently generated neurons to different laminae as well as to the deployment of axons in a manner that respects laminar boundaries.