bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative distribution of dopamine D‐1 and D‐2 receptors in the basal ganglia of turtles, pigeons, rats, cats, and monkeys
Authors: Richfield Eric K. , Young Anne B. , Penney John B. 
Published: January 2005

AbstractThe distribution and density of dopamine D‐1 and D‐2 receptors were studied in the basal ganglia of adult turtles, pigeons, rats, cats, and monkeys. Dopamine receptors were measured in vitro by quantitative autoradiography in alternate sections processed for D‐1 and D‐2 receptor subtypes and compared to adjacent sections stained for acetylcholinesterase (AChE) activity. [3H]‐SCH 23390 and [3H]‐spiroperidol were used to label the D‐1 and D‐2 dopamine receptor subtypes, respectively.The anatomic distribution of both D‐1 and D‐2 receptors in the basal ganglia was remarkably similar across all species examined. Whereas the absolute number of D‐1 and D‐2 receptors in the basal ganglia varied between species, the percentage of D‐1 and D‐2 receptors in a region was quite similar among species.The pattern of binding to the D‐1 and D‐2 receptor varied among the different species. The adult turtles, pigeons, and rats demonstrated non‐patchy D‐1 and D‐2 receptor binding in the striatum and pallidum. The adult cat and monkey caudate nucleus and putamen demonstrated mildly heterogeneous receptor binding in a pattern that differed from that seen with AChE staining, but did occasionally demonstrate similar patterns of the D‐1 and D‐2 receptor subtypes, The immature cat striatum was characterized by heterogeneous D‐1 receptor binding that corresponded to heterogeneous AChE rich patches, whereas D‐2 receptor binding was homogeneous.Heterogeneous binding was seen in other basal ganglia structures including the nucleus accumbens, olfactory tubercle, and substantia nigra pars compacta and reticulata. Complementary D‐1 and D‐2 receptor binding patterns were seen in the pallidum and substantia nigra of the mammals.The results of this study indicate that both D‐1 and D‐2 dopamine receptors are present in the basal ganglia of five different vertebrates. A common feature of dopamine receptors in the basal ganglia is their heterogeneity in distribution and density. The heterogeneity of dopamine receptors has similarities to and differences from the distribution of presynaptic dopamine and other neurotransmitter markers of the basal ganglia.
Morphological analysis of the tuberomammmillary nucleus in the rat brain: Delineation of subgroups with antibody again L‐histidine decarboxylase as a marker
Authors: Ericson H. , Watanabe T. , Köhler C. 
Published: January 2005

AbstractWith an antibody specific for L‐histidine decarboxylase (HD) in combination with immunohistochemical techniques and retrograde fluorescent tracing, the morphology, distribution, and projections of the histamineragic neurons of the posterior hypothalamus were studied in the adult male rat.Magnocellular neurons, situated on both sides of the mammillary recess and close to the ventral surface of the brain rostral and caudal to the mammillary bodies, were found to contain HD‐immunoreactivity (HD‐i). In addition to these magnocellular neurons, a substantial number of small and medium‐sized neurons were immunostained, as were strands of cells of all sizes bridging the HD‐i cell groups: A detailed mapping of the HD‐i cells in frontal, sagittal, and horizontal sections showed that these neurons make up one continuous cell group, defined as the tuberomammillary nucleus (TM). This nucleus can be divided into several subgroups. Thus, approximately 600 HD‐i neurons situated on each side of the mammillary recess compose the medial subgroup of the TM (TMM). The ventral subgroup of the TM (TMV) consists of some 1,500 neurons situated at the ventral surface of the brain, rostral (TMVr) and caudal (TMVC) to the mammillary bodies. The TMM contains a greater proportion of parvicellular neurons compared to the TMV. About 100 HD‐i cells are scattered within the lateral hypothalamic area, the posterior hypothalamic region, the perifornical area, the supramammillary nucleus, and the dorsomedial hypothalamic nucleus. These cells are collectively named the diffuse part of the TM (TMdiff).The morphological differences between the TMM and the TMV did not signal differences in the efferent connections of these subgroups. Thus, single injections of the fluorescent tracer Fast Blue into different regions of the brain, including the spinal cord, resulted in retrograde labeling of HD‐i neurons, which were distributed throughout the TM with no discernible topographic pattern. More specifically, each subgroup of the TM contributed projections innervating or passing through a large number of brain regions, including the olfactory bulb, hippocampus, caudate nucleus, paraventricular and supraoptic nuclei of the hypothalamus, cerebellum, tectum, medulla, and spinal cord. The widespread projections of the HD‐i neurons contrasted to the more specific projections observed from non HD‐i neurons in cell groups situated around the TM.Taken together, these findings suggest that the HD‐i cells of the posterior hypothalamus constitute one major nucleus, the TM, and that this nucleus may be subdivided into three components, each of which has diffuse projections throughout the neuraxis.
Primary afferent and propriospinal fibers in the rat dorsal and dorsolateral funiculi
Authors: Chung Kyungsoon , Langford Lauren A. , Coggeshall Richard E. 
Published: January 2005

AbstractThe purpose of this study is to determine the numbers of primary afferent and propriospinal fibers in the dorsal and dorsolateral funiculi of the rat. The reason for concentrating on these areas is that they contain large numbers of unmyelinated axons. Our data are axonal numbers from the S2 segment of spinal cord in animals that had unilateral dorsal rhizotomies or spinal cord isolations. The major conclusions are (1) that 23% of the primary afferent fibers in the dorsal funiculus are unmyelinated; (2) that there are approximately 12,500 unmyelinated primary afferent fibers in the dorsolateral funiculus, which is more than the number of primary afferent fibers in the dorsal funiculus and tract of Lissauer combined, and (3) that approximately 25% of the axons in the dorsal funiculus and 44% of the axons in the dorsolateral funiculus are propriospinal. These data modify and extend previous ideas of the organization of spinal white matter.
Development of the sex difference in neuron numbers of the superior cervical ganglion: Effects of transection of the cervical sympathetic trunk
Authors: Wright L. L. 
Published: January 2005

AbstractThe number of superior cervical ganglion (SCG) neurons does not differ for males and females on the day of birth, but by 15 days, after most of the normal neuron death has occurred, males have significantly more neurons than females. This difference persists in the adult. The present study was undertaken to determine whether the presence of afferent input to the SCG is required for the development of this sex difference.Bilateral transection of the cervical sympathetic trunk, which deafferents the SCG neurons, or a sham operation was performed on male and female Sprague Dawley rats on the day of birth. Numbers of neurons were counted in SCGs of animals sacrificed on either postnatal day 4 or 15, before or after normal development of the SCG sex difference.At 4 days, the number of SCG neurons in sham‐operated males and females were not different, but by 15 days, females had lost a significant number of neurons, whereas the males had not. Transection of the cervical sympathetic trunk led to a significant loss of over 6,000 SCG neurons by postnatal day 4 in both males and females. Whereas some of this loss is due to axotomy of caudally projecting SCG neurons, at least half of the neuron loss is due to removal of the afferent input, At 15 days, sham‐operated males had significantly more SCG neurons than did sham‐operated females, but the gender difference was not significant in animals with neonatally deafferented ganglia. Thus, the normal development of the gender difference in SCG neuron numbers requires an intact afferent input.
Distribution and organization of cholinergic neurons in the rat forebrain demonstrated by computer‐aided data acquisition and three‐dimensional reconstruction
Authors: Schwaber James S. , Rogers Wade T. , Satoh Keiji , Fibiger H. C. 
Published: January 2005

AbstractAn understanding of the organization of cholinergic neurons in the central nervous system has been an important objective for many years. By developing and applying a new electronic method for mapping tissue sections, we have generated original graphic and quantitative findings on forebrain cholinergic neurons that provide new insight into their distribution and organization. Satoh, Armstrong, and Fibiger (Brain Res. Bull. 11:693–720, 1983) have proposed that in the basal forebrain cholinergic neurons with long axons form a continuum rather than being arranged as a series of discrete nuclear groups. It has been difficult, however, by conventional methods of data analysis and display, to test this hypothesis. By using a digital microscopy system, the position of every cholinergic neuron was marked with 1‐μm resolution in tissue sections taken at 90‐μm or 180‐μm intervals through the entire distribution of these neurons in the forebrain. The three‐dimensional reconstruction of these neurons in context shows them to be distributed as a continuous cell column. The column twists and changes position as it is deformed by adjacent neuronal structures, such that its shape and continuity would not be apparent without reconstruction into a computer graphics model. Complementary analyses of the distribution of cholinergic interneurons in dopamine‐rich regions of the forebrain indicated that there are regional differences between striatal and olfactory tubercle neurons. Cellular morphometry analyses show the population of cholinergic neurons in the rat to be surprisingly homogenous in size, but not in shape. Graphic and quantitative analyses indicated that there is a striking relationship between the distributions of projection and interneuronal cell groups.We conclude that the basal forebrain cholinergic neurons form a continuum. The chemoarchitecture of this cell group does not conform to the usual cytoarchitectural divisions. The present, results, however, taken together with the findings based on Nissl‐stained sections and connectional and biochemical data, suggest that the region of this neurochemically defined continuum should be reexamined for consideration as a single functional entity or nucleus: a cholinergic basal nuclear complex.
Growth of hippocampal mossy fibers: A lesion and coculture study of organotypic slice cultures
Authors: Zimmer Jens , Gähwiler Beat H. 
Published: January 2005

AbstractIn hippocampal slice cultures, the mossy fibers from the dentate granule cells project as normally to cells in the dentate hilus (CA4) and the hippocampal CA3 pyramidal cells. After lesions in vivo and intracerebral transplantation, the mossy fibers can alter their normal distribution within CA3 and even contact CA1 pyramidal cells. The present study examined whether similar changes could be induced in the more simple, virtual two‐dimensionally organized slice cultures. For this purpose slices of 7‐day‐old hippocampal were prepared and subjected to one of the two following manipulations: (1) transection of the mossy fiber layer in CA3 or (2) rearrangement of the geometrical relations between the dentate granule cells in their potential targets (CA3 and CA1) by coculturing dentate slices with CA3 or CA1 slices. Two to 8 weeks later the distribution of the mossy fiber system was visualized by histochemical Timm sulphide silver staining of the terminals.The distribution of the mossy fiber system observed in previous studies of ordinary hippocampal slice cultures was confirmed. In addition, mossy fibers were found to cross the cuts through the mossy fiber layer with formation of a reduced number of characteristic Timm‐stained terminals in CA3 distal to the lesion. Close proximity and contiguity of the cut surfaces were important for such growth to occur. Significantly fewer mossy fiber terminals were found when separate slices of dentate and CA3 tissue were joined and grown as cocultures. Similar apposition of slices of dentate and CA1 tissue only rarely resulted in the ingrowth of mossy fibers into CA1. The Timm‐stained mossy fiber terminals were then of subnormal size.The results show the potentials of the slice culture technique in suplementing lesion and transplant studies in situ. The growth of mossy fibers across a transection of their pathway is thus a new observation, difficult to demonstrate in the brain. The limited growth in the cocultures of aberrant mossy fibers into Cal does, on the other hand, emphasize the importance of close structural contact for the formation of nerve connections, and such contact is apparently more easily obtained in the brain. When the growth of the mossy fibers and that of the cholinergic septohippocampal fibers are compared, it is evident that the cholinergic axons grow better both in vitro and in vivo after lesions and transplantation.
Ascending projections to the mammillary nuclei in the rat: A study using retrograde and anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase
Authors: Shibata Hideshi 
Published: January 2005

AbstractCells of origin of ascending afferents to the mammillary nuclei and the afferents' fields of termination within these nuclei were studied by using retrograde and anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase in the rat.The pars compacta of the superior central nucleus projects bilaterally to the median region of the medial mammillary nucleus. The ventral tegmental nucleus projects ipsilaterally to the medial mammillary nucleus, except for its median region, in a topographic manner such that the rostrodorsolateral part of the ventral tegmental nucleus projects to the medial quadrant of the medial mammillary nucleus; the rostroventromedial part projects to the dorsal quadrant; the caudodorsolateral part projects to the ventral quadrant; and the caudoventromedial part projects to the lateral quadrant. These projection fields extend throughout the longitudinal axis of the medial mammillary nucleus, except for its most caudal region, to which only the dorsolateral part of the ventral tegmental nucleus projects. This nucleus also projects topographically to the ipsilateral dorsal premammillary nucleus; the rostral part of the ventral tegmental nucleus projects to the dorsal part of the dorsal premammillary nucleus, whereas the caudal part projects to the ventral part. The periaqueductal gray around the dorsal tegmental nucleus projects bilaterally to the supramammillary nucleus. The pars alpha of the pontine periaqueductal gray projects bilaterally to the peripheral part of the lateral mammillary nucleus, whereas the pars ventralis of the dorsal tegmental nucleus projects ipsilaterally to the lateral mammillary nucleus.The results show that the tegmentomammillary projections are organized in a gradient fashion, with the rostral to caudal position of cells of origin within the tegmental nuclei of Gudden being reflected by the medial to lateral position of fields of termination within the mammillary nuclei.
Exogenous matrix precursors promote functional nerve regeneration across a 15‐mm gap within a silicone chamber in the rat
Authors: Williams Lawrence R. , Danielsen Nils , Müller Harald , Varon Silvio 
Published: January 2005

AbstractWhen silicone regeneration chambers are implanted empty, axonal regeneration fails if the interstump gap length is greater than 10 mm. Previous experiments using the 10‐mm gap model demonstrated that regeneration success correlated with the dimension and/or consistency of the naturally formed acellular fibrin matrix. Both spatial and temporal parameters of regeneration could be stimulated through modifications of the fibrin matrix by prefilling the chambers at the time of implantation either with phosphate‐buffered saline or plasma dialyzed against phosphate‐buffered saline. In the present experiments, similar modification of matrix formation was found to promote successful regeneration across 15‐mm and 20‐mm interstump gap lengths. In addition, prefilling 15‐mm‐gap chambers with dialyzed plasma resulted in a 3.5‐fold increase in the incidence of functional restitution detected at 8 weeks after implantation over the outcome with chambers prefilled with phosphate‐buffered saline.
Primary neurons of the lateral line nerves and their central projections in hagfishes
Authors: Kishida R. , Goris R. C. , Nishizawa H. , Koyama H. , Kadota T. , Amemiya F. 
Published: January 2005

AbstractThe hagfish lateral line system was studied by horseradish peroxidase transganglionic transport. The anterior lateral line nerve innervates the group of lateral line canals situated anteriorly to the eye, and the posterior lateral line nerve innervates the group of canals situated posteriorly to the eye. Although both nerves pass through the muscle fascia at the same point, each runs a different course to the brain. The anterior lateral line nerve runs near the trigeminal nerve and its ganglion is closely attached to the trigeminal ganglion, but both systems are completely independent. The posterior lateral line nerve runs independently of any other cranial nerve and makes a peculiar U‐turn at the point of entry to the brain capsule. The anterior lateral line ganglion contains both cutaneous sensory cells (small to large cells) and lateral line sensory cells (small cells); from this ganglion projections run to both the trigeminal sensory nucleus (fine and thick fibers) and medial nucleus of the area acousticolateralis (fine fibers). The posterior lateral line ganglion contains only small lateral line cells that project fine fibers to the medial nucleus of the area acousticolateralis. There are no efferent components in this lateral line system, and its only afferent terminal field is the medial nucleus of the area acousticolateralis.
Descending projection neurons to the spinal cord of the goldfish, Carassius auratus
Authors: Rao P. D. Prasada , Jadhao A. G. , Sharma S. C. 
Published: January 2005

AbstractThe sources of descending spinal tracts in the goldfish, Carassius auratus, were visualized by retrograde transport of horseradish peroxidase (HRP) administered to the hemisected spinal cord. In the diencephalon, HRP‐positive neurons were identified in the nucleus preopticus magnocellularis pars magnocellularis and ventromedial nucleus of the thalamus of the ipsilateral side. In the mesencephalic tegmentum, a few somata of the contralateral nucleus ruber and several ipsilateral neurons of the nucleus of the median longitudinal fasciculus were labeled. The reticular formation of the rhombencephalon was the major source of descending afferents to the spinal cord. A larger number of neurons were retrogradely labeled in the ipsilateral superior, middle, and inferior nuclei than in the contralateral nuclei. A few raphe neurons and the contralateral Mauthner neuron were also HRP‐positive. The octaval area showed retrogradelyl labeled neurons in the anterior, magnocellular, descending, and posterior octaval nuclei of the ipsilateral side. A large number of neurons in the facial lobe and a few somata located adjacent to the descending trigeminal tract were labeled on the ipsilateral side. The pattern of descending spinal projections in goldfish is comparable to that of tetrapods and suggests that the spinal tracts have originated quite early in the course of vertebrate evolution.
Functional topography of the rat hypothalamic dopamine neuron systems: Retrograde tracing and immunohistochemical study
Authors: Kawano Hitoshi , Daikoku Shigeo 
Published: January 2005

AbstractThe origins of the dopamine (DA)‐containing nerve terminals in the external layer of the median eminence and in the neurointermediate pituitary were determined in rats by a combination of retrograde labeling with wheat germ agglutinin (WGA) and immunohistochemistry for tyrosine hydroxylase (TH) Biotinylated WGA (b‐WGA) was injected into the posterior pituitary (group 1) and into the median eminence (group 2). In group 1 animals, all the magnocellular neurons of the paraventricular, supraoptic, and accessory nuclei, and many parvicellular neurons in the rostral periventricular region (RPR) were labeled with WGA. In group 2 animals, many neurons were labeled in the arcuate nucleus and the RPR, and in a small population of the preoptic‐septal region. In group 1 animals, about 39% of TH neurons in the RPR were labeled with WGA, whereas only a few TH neurons (1%) in the arcuate nucleus were labeled with WGA. In group 2 animals, on the contrary, almost all TH neurons (73%) in the arcuate nucleus carried WGA, whereas in the RPR, only some of the TH neurons (19%) were labeled with WGA. It is concluded that DA neurons involved in the hypothalamic‐anterior pituitary axis are located in the arcuate nucleus; those involved in neuro‐intermediate lobe function in the RPR.
Small vesicle bouton synapses on the distal half of the lateral dendrite of the goldfish mauthner cell: Freeze‐fracture and thin section study
Authors: Tuttle Rebecca , Masuko Sadahiko , Nakajima Yasuko 
Published: January 2005

AbstractTo understand principles of synaptic integration, it is necessary to define the types of synapses on a particular neuron and their distribution. Thin sectioning and double replica freeze‐fracture techniques were employed to characterize the small vesicle bouton (SVB) synapses on the distal half of the Mauthner (M) cell lateral dendrite, which probably mediate a remote dendrite inhibition. Throe morphologically distinct SVB synapses, types A, B, and C, were found. These three SVB synapses form roughly 90% of the synapses on the distal half of the lateral dendrite, with types A and B being most common.The SVB A synapse is characterized by mostly oval and round synaptic vesicles, a discrete presynaptic active zone with a highly variable shape, and a postsynaptic active zone with no apparent particle aggregate in either the E or P face.At the SVB B synapse, most of the synaptic vesicles are flat. A very high particle density is present throughout the presynaptic P face, and vesicle attachment sites are dispersed over much of the presynaptic membrane, Postsynaptic P face particle aggregates are subjacent to the presynaptic vesicle attachment sites, and are often large and anastomosing.The SVB C synapse is characterized by synaptic vesicle profiles that vary from flattened to round. The SVB C cytoplasm was unclouded by the flocculent material that characterized SVBs A and B. The presynaptic active zones at the SVB C synapse are discrete, and macular or oblong. No particle aggregates are apparent in the postsynaptic active zone.Small, macular particle aggregates were found in nonactive zone regions of the postsynaptic E face of all three types of SVBs. Small subsurface cisterns were also observed underlying the M cell membrane at all three types of SVB synapses. Neither the postsynaptic E face aggregates nor the subsurface cisterns were ever observed directly subjacent to presynaptic active zones, but were often seen adjacent to active zones.Short, straight rows of particles and short cylinders were often seen in both pre‐ and postsynaptic surrounding zone regions of SVB A and C synapses. These structures are thought to represent tight junctions.