bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of catecholaminergic projections to the spinal cord in the North American opossum, Didelphis virginiana
Authors: Pindzola Ronda R. , Ho Raymond H. , Martin George F. 
Published: January 2005

AbstractThe intent of our study was to determine when catecholaminergic axons grow into each of their adult targets in the spinal cord of the North American opossum (Didelphis virginiana) and to identify the origin of catecholaminergic axons in the lumbosacral cord at different stages of development. Tyrosine hydroxylase‐like immunoreactive axons, presumed to be catecholaminergic, were demonstrated at different stages of development by the indirect antibody peroxidase‐antiperoxidase technique of Sternberger. The neurons giving rise to such axons in the lumbosacral cord were identified by using the retrograde transport of Fast Blue and immunofluorescence for tyrosine hydroxylase‐like immunoreactive neurons.At birth, 12‐13 days after conception, tyrosine hydroxylase‐like immunoreactive axons are present in the marginal zone throughout the length of the spinal cord. Such axons are particularly numerous in the dorsolateral marginal zone, the region containing most of them in adult animals. By postnatal day 3, a few immunoreactive axons are present in the intermediate (mantle) zone of the spinal cord; and by postnatal day 8, they are most concentrated in the presumptive intermediolateral cell column. Laminae I and II of the dorsal horn are not innervated by such axons until approximately postnatal day 15. By postnatal day 44, the distribution of tyrosine hydroxylase‐like immunoreactive axons in the spinal cord resembles that in adult animals, although some areas may be hyperinnervated.At birth, tyrosine hydroxylase‐like immunoreactive cell bodies are present in all of the brainstem areas providing catecholaminergic projections to the spinal cord in adult animals (Pindzola et al.: Brain Behav. Evol. 32:281‐292,'88); and by at least postnatal day 5, lumbosacral injections of Fast Blue retrogradely label tyrosine hydroxylase‐like immunoreactive neurons in all such areas. Retrogradely labeled immunoreactive neurons were also found in areas that do not contain them in adult animals. Such areas include the dorsal part of the nucleus coeruleus and certain areas of the reticular formation. During development, spinally projecting tyrosine hydroxylase‐like immunoreactive neurons are numerous medial to the nucleus ventralis lemnisci lateralis (the paralemniscal region), whereas only a few are present in the same location in adult animals. Our results suggest that catecholaminergic axons grow into the spinal cord prenatally, that they innervate their adult targets postnatally and over an extended time period, and that during some stages of development they originate from areas that do not supply them in the adult animal.
Control of neuronal survival by anomalous targets in the developing brain
Authors: Linden Rafael 
Published: January 2005

AbstractDescribed here is an aberrant parabigeminothalamic projection that follows neonatal lesions of the superior colliculus in rats, with evidence that this anomalous projection may sustain a normal number of neurons in the parabigeminal nucleus after early removal of the latter's tectal target. The aberrant projection was traced radioautographically to the tectorecipient zone of the lateral posterior nucleus after an injection of tritiated amino acid in the parabigeminal nucleus. Histochemical staining for cholinesterase revealed an anomalous patch of high enzyme activity in register with both the aberrant parabigeminothalamic projection and an abnormal retinal projection that also follows tectal lesions. Histochemical staining after either binocular enucleation or a tegemental lesion made simultaneous with the tectal ablation showed that the anomalous enzyme patch is a reliable marker of the aberrant parabiogeminothalamic projection. It was also shown that the retinal projection is not needed for the formation of the anomalous parabigeminothalamic pathway. Ablation of the superior colliculus at birth failed to produce a net cell loss in the contralateral middle division of the parabigeminal nucleus after the period of natural neuronal death. Lesions extending toward the anomalous terminal field in the lateral posterior nucleus, however, prevented the survival of a normal number of neurons in the parabigeminal nucleus. When the unilateral tectal ablation was made together with a lesion of the ipsilateral posterior neocortex that produced cell loss in the thalamus, the number of neurons remaining in the middle division of the contralateral parabigeminal were linearly related to the cell content of the lateral posterior nucleus. We conclude that the anomalous target in the tectorecipient zone of the lateral posterior nucleus effectively replaces the normal projection field in the superior colliculus, with regard to the trophic requirements for neuronal survival during development of the parabigeminal nucleus.
Serotoninergic innervation of the locust mandiblar closer muscle modulates contractions through the elevation of cyclic adenosine monophosphate
Authors: Baines Richard A. , Tyrer N. Mark , Downer Roger G. H. 
Published: January 2005

AbstractThe mandibular closer muscles of the locust receive innervation that is immunoreactive for the putative transmitter 5‐hydroxytrptamine (5‐HT). Cobalt‐labelling suggests that the origin of this innervation is a group of cells located anteriorly in the suboesophageal ganglion. Bath application of 5‐HT while the muscles are active produces marked changes in the contractions, increasing their amplitude, rate of contraction, and rate of relaxation. Incubation of isolated muscles with 5‐HT shows that this amine elevates the levels of the cyclic nucleotide cyclic adenosine monophosphate (cAMP). In addition compounds that artificially elevate the levels of cAMP in the muscle‐3‐isobutyl‐1‐methylxanthine (IBMX), forskolin, and the cAMP analogue 8‐(4‐chlorophenylthio) cAMP‐mimic the actions of 5‐HT, whereas a potent inhibitor of insect adenylate cyclase, adenosine, considerably delays the onset of the effects produced by 5‐HT.The effects observed with 5‐HT in the mandibular muscle are similar to those of octopamine in the locust extensor tibiae muscle, and it is possible that this is an analogous modulatory system.
Serotoninergic and noradrenergic projections to the ventral posterolateral nucleus of the monkey thalamus
Authors: Westlund Karin N. , Sorkin Linda S. , Ferrington Dale G. , Carlton Susan M. , Willcockson Helen H. , Willis W. D. 
Published: January 2005

AbstractIn the present study, serotoninergic and noradrenergic varicosities were identified in the ventral posterolateral nucleus of the macaque monkey. Monoaminergic neurons projecting to the ventral posterolateral nucleus of the thalamus were identified by using retrograde labeling with horseradish peroxidase combined with immunocytochemical staining for serotonin or dopamine‐β‐hydroxylase. The midbrain nucleus raphe dorsalis was the major site of origin for neurons providing a serotoninergic projection to the ventral posterolateral nucleus. A few retrogradely labeled serotonin‐containing neurons were also observed in the central superior and the raphe pontis nuclei. Noradrenergic cells with projections to the thalamus were primarily located in the nucleus locus coeruleus with some projection neurons in the nucleus subcoeruleus, and the A5 catecholamine cell group of the pons.
Innervation and geometry of rabbit ciliary ganglion cells after preganglionic nerve regeneration
Authors: Hadley Robert D. 
Published: January 2005

AbstractPrevious studies have shown a consistent relationship between the dendritic complexity of autonomic neurons and the number of preganglionic axons that innervate them. This relationship is established postnatally, probably through mitigation of preganglionic competition on neurons with increasing dendritic complexity. The present study examines whether a similar relationship between neuronal geometry and the number of axons that innervate rabbit ciliary ganglion neurons is established when the preganglionic nerve is interrupted and then allowed to regenerate. Such a pattern would indicate that the mechanisms responsible for establishing the relationship between innervation and postsynaptic geometry in neonates persist in the adult animal.Ganglion cells were fully reinnervated by about 8 weeks after preganglionic nerve crush. On average, the number of inputs to reinnervated neurons was similar to normal (range = 1 to 4 inputs/cell, mean = 2.1).The number of inputs that cells received was related to their dendritic complexity. Neurons that received a single input had very simple dendritic arbors, or lacked dendrites altogether, whereas neurons that received 2 or more inputs had considerably more complex arbors.The correlation between dendritic complexity and innervation suggests that the geometry of postsynaptic neurons continues to influence the number of inputs each ganglion cell receives in maturity. As a corollary, changes in the dendritic arbors of adult neurons would presumably influence the arrangement of their synaptic inputs.
Regenerative organization of the trigeminal ganglion following mental nerve section and repair in the adult rat
Authors: Zuniga John R. , Pate Jenifer D. , Hegtvedt Arden K. 
Published: January 2005

AbstractSequential double‐fluorescence labeling techniques were employed to determine the regenerative somatotopic organization of first‐order mandibular neurons following mental nerve transection and surgical repair in the adult rat. Twenty‐four ganglia from 12 adult rats were examined microscopically in the following double‐labeling paradigm: (i) Fast Blue was injected directly into the mental nerves bilaterally; (ii) 7 days later the nerves were transected and immediately rejoined by microscopic suture techniques; (iii) Diamidino Yellow was then injected directly into the regenerated nerve, distal to the point of repair, 30, 60, and 90 days postrepair; and (iv) the animals were sacrificed 3 days later and the ganglia removed for fluorescent microscopic examination. Results were compared with 12 ganglia each of unrepaired/resected controls and sham surgery controls made in parallel.The organization of fluorescence‐labeled mandibular cells followed an orderly somatotopic distribution along the lateral dorsoventral axis of the trigeminal ganglion in all groups. The difference in mean total number of fluorescence‐labeled cells within and between groups was insignificant or minimal. There was no evidence of heteronymous (nonmandibular) or homonymous (mandibular) sprouting following neuronal regeneration. Regeneration, as determined by the presence of double‐labeled cells, was negligible if the transection injury was not repaired but significant 30 days following repair. Additionally, mandibular regeneration gradually improved, as shown by the significant increase of double‐labeling at 60 and 90 days postrepair. However, 90 days later, the percentage of regenerated cells had not reached sham control conditions.The results of these studies suggest that following nerve transection and immediate repair in the adult rat: (i) mental sensory neuronal perikarya regenerate from and maintain an organized somatotopic area within the mandibular division of the trigeminal ganglion; (ii) reorganization by collateral sprouts from nonmental sensory mandibular and/or nonmandibular trigeminal ganglion cells is not evident or is negligible in the adult rat; and (iii) regeneration of resected trigeminal sensory neurons is a gradual process which is enhanced by immediate surgical intevention.
Distribution of calcium‐activated protease calpain in the rat brain
Authors: Perlmutter Lynn S. , Gall Christine , Baudry Michel , Lynch Gary 
Published: January 2005

AbstractCalpain is a calcium‐activated neutral protease that degrades a number of cytoskeletal proteins. It may participate in the maintenance of the cytoskeleton and in the rapid turnover of structural proteins associated with synaptic plasticity. Calpain may also be involved in the neurodegeneration that accompanies aging and age‐related diseases. To aid in the interpretation of disease‐related alterations in staining patterns, the present study examined calpain's normal distribution in the mammalian brain and spinal cord. A monoclonal antibody was employed with the avidin‐biotin‐peroxidase immunocytochemical technique on samples of rat tissue. Glia (astrocytes, microglia) and virtually all neurons were immunopositive, although neuronal processes exhibited varying staining patterns. The axonal staining pattern depended upon either the origin or destination of the process: those axons remaining within the brain (e.g., corpus callosum) were only lightly immunoreactive, whereas spinal cord and peripheral axons (trigeminal nerve) were more darkly labeled. The architecture of the dendritic tree determined the dendritic staining pattern: neurons with prominent apical and basal dendritic trees (e.g., pyramidal cells) were immunolabeled along their entire extent; labeling of multipolar cells (e.g., hilar cells of dentate gyrus) was limited to the proximal dendrites. The ubiquitous distribution of calpain argues against a primary role for the enzyme in the regional pattern of neuronal death seen in Alzheimer's disease. An alteration in the concentration, localization, or inhibition of the enzyme could, however, lead to the abnormal accumulations of cytoskeletal elements seen with the disease.
Effects of monocular deprivation on the morphology of retinogeniculate axon arbors in a primate
Authors: Lachica E. A. , Crooks M. W. , Casagrande V. A. 
Published: January 2005

AbstractPrevious studies of the monocularly deprived (lid‐sutured) primate (Galago crassicaudatus) have shown that magnocellular (M) and parvocellular (P) lateral geniculate nucleus (LGN) cells that receive input from the deprived eye are smaller than counterparts that receive input from the nondeprived eye; deprived koniocellular (K) cells show wide variability in size, but they do not differ from their nondeprived counterparts (Casagrande and Joseph, '80)‐ Although deprivation results in cell‐size changes, the physiological properties of deprived LGN cells do not change from normal (that is, P cells have normal X‐like properties, M cells have normal Y‐like properties, and K cells have normal W‐like properties)Because of these findings, we were interested in determining how the morphology of retinogeniculate axon arbors is affected by deprivation. To this end, 104 horseradish‐peroxidase‐filled retinogeniculate arbors from galagos deprived from birth to maturity were completely reconstructed within the binocular segment of the LGN. These arbors were qualitatively and quantitatively compared with 56 arbors reconstructed from normal galagos as part of another study (Lachica and Casagrande, '88)Our main findings are as follows. Deprived M and P arbors are affected by deprivation in the same general manner: compared with normal arbors, they are altered in shape (rather than being round or columnar, respectively, both groups have terminals that are elongated parallel to laminar borders); they are smaller in area, and they have fewer boutons but innervate the LGN with a greater density of boutons. K arbors are affected by deprivation in the same manner, but less severely. Finally, our results show that nondeprived arbors are also affected by eyelid suture. Specifically, all nondeprived arbor groups are smaller in area than normal and possess more boutons/mm3. We interpret these changes in the morphology of deprived retinogeniculate axons to suggest that abnormal competitive interactions begin by affecting primarily immature LGN cells and their axons and that the retinogeniculate axons presynaptic to these cells experience secondary degenerative effects. Our results also show that similar manipulations of visual experience can result in changes that are not necessarily comparable across species such as cats and primates.
Origins and distribution of cerebrovascular nerve fibers showing calcitonin gene‐related peptide‐like immunoreactivity in the major cerebral artery of the dog
Authors: Nozaki Kazuhiko , Uemura Yoshihiko , Okamoto Shinichiro , Kikuchi Haruhiko , Mizuno Noboru 
Published: January 2005

AbstractThe origins and overall distribution of perivascular nerve fibers showing calcitonin gene‐related peptide‐like immunoreactivity (CGRP‐LI) in the major cerebral arteries were investigated immunohistochemically in the dog by using whole‐mount preparations of the arterial trees around the circle of Willis. Perivascular nerve fibers with CGRP‐LI were seen most abundantly in the basilar artery, vertebral artery, common anterior cerebral artery, proximal part of the anterior cerebral artery, and terminal part of the internal carotid artery. They were far less numerous in the middle cerebral artery, posterior cerebral artery, superior cerebellar artery, and distal part of the anterior cerebral artery. Neuronal cell bodies with CGRP‐LI were observed in the trigeminal, nodose, superior cervical, and dorsal root ganglia.CGRP‐LI fibers in the large pial arteries in the circle of Willis were eliminated ipsilaterally after unilateral transection of the ophthalmic division of the trigeminal nerve, and slightly reduced in number ipsilaterally after unilateral transection of the maxillary division of the trigeminal nerve. They did not show any noticeable changes after unilateral transection of the mandibular division of the trigeminal nerve. On the other hand, CGRP‐LI fibers in the basilar and vertebral arteries did not show any appreciable changes after unilateral transection of the trigeminal nerve, but they were eliminated after bilateral ganglionectomy of the dorsal root ganglia of the first, second, and third cervical nerves. After ganglionectomy of the ciliary, pterygopalatine, otic, nodose, or superior cervical ganglion, no changes were observed in perivascular nerve fibers with CGRP‐LI in the major cerebral arteries.The data indicate that perivascular nerve fibers with CGRP‐LI in the large pial arteries forming the circle of Willis originate mainly from the ophthalmic division of the trigeminal nerve, and partly from the maxillary division of the trigeminal nerve, and that CGRP‐LI fibers in the basilar artery and distal part of the vertebral artery originate mainly from the dorsal root ganglia of the upper cervical nerves.
Distribution of phosphate‐activated glutaminase in the human cerebral cortex
Authors: Akiyama Haruhiko , Kaneko Takeshi , Mizuno Noboru , McGeer Patrick L. 
Published: January 2005

AbstractPhosphate‐activated glutaminase (PAG), which catalyses conversion of glutamine to glutamate, is a potential marker for glutamatergic, and possibly GABA, neurons in the central nervous system. A polyclonal antibody, raised in rabbits against rat brain PAG, was applied to postmortem human brain tissue to reveal the distribution of PAG in the cerebral cortex. PAG immunoreactivity was observed in pyramidal and non‐pyramidal neurons but not in glial cells. In the neocortex, large to medium‐sized pyramidal neurons in layers III and V were stained most intensely, while the majority of smaller pyramidal cells were labeled either lightly or moderately. Such modified pyramids as the giant Betz cells, the large pyramidal cells of Meynert, and the solitary cells of Ramón y Cajal were also stained intensely. Fusiform cells in layer VI showed moderate to intense labeling. A number of cortical non‐pyramidal neurons of various sizes stained moderately to intensely. These included large basket cells which were identified by their characteristic morphology and size in primary cortical areas. Pyramidal cells in the hippocampal formation as well as basket cells of the stratum oriens stained moderately to intensely. Since pyramidal cells are believed to be glutamatergic and large basket cells GABAergic, these results suggest that PAG plays a role in generating not only transmitter glutamate, but also GABA precursor glutamate.
Topographic intermingling of striatonigral and striatopallidal neurons in the rhesus monkey
Authors: Selemon L. D. , Goldman‐Rakic P. S. 
Published: January 2005

AbstractThe topography and interrelationship of striatofugal neurons have been examined using a double retrograde tracing paradigm to label striatopallidal and striatonigral neurons in the same neostriatum. The rostral globus pallidus and the rostral substantia nigra in the same hemisphere were injected simultaneously with fluorescent tracers in three monkeys. In addition, the caudal globus pallidus and the caudal substantia nigra were injected separately in a fourth and fifth monkey with a fluorescent dye and wheat germ agglutinin‐horseradish peroxidase (WGA‐HRP), respectively. Digitized plots of fluorescent dye‐labeled neurons revealed that large numbers of striatonigral projection neurons lie within both neostriatal nuclei, i.e., the caudate and putamen. Similarly, neurons innervating the globus pallidus were found in both caudate and putamen. The distribution of retrogradely labeled neurons observed was consistent with the topography of striatofugal projections that has been described previously, i.e., the rostrocaudal and mediolateral axes of the neostriatum are preserved in the striatopallidal and striatonigral projections (e.g., Szabo, '62, '67, 70, '72) and the dorsoventral axis is inverted in the projection of the neostriatum onto the nigra but not in the striatopallidal projection (Nauta and Domesick, '79; Gerfen, '85). Analysis of cases in which striatonigral and striatopallidal neurons were present in large numbers within the same region of the neostriatum disclosed that the two populations are intermingled such that small clusters of striatopallidal neurons are surrounded by striatonigral neurons and vice versa. The clustered arrangement of striatofugal neurons observed in the fluorescent cases was unambiguous in a case in which HRP was injected into the caudal substantia nigra. In this case, both anterogradely labeled terminals and retrogradely labeled neurons exhibited a striking, compartmental‐like distribution in the posterior putamen.Our observations indicate that the matrix compartment of the neostriatum is comprised of a patchwork of interposed clusters of nigral and pallidal efferent neurons. We hypothesize that these clusters of efferent neurons may direct interdigitated cortical inputs into distinct nigro‐and pallido‐thalamic pathways. In view of the parallel nature of processing throughout the basal ganglia, it appears that convergence of these segregated nigral and pallidal loops must occur at the cortical level where prefrontal and premotor targets of the basal ganglia are interconnected via corticocortical projections (Selemon and Goldman‐Rakic, '88).