bluuebunny/crossref_metadata_2025_split huggingface dataset:
Localization of cannabinoid receptor mRNA in rat brain
Authors: Matsuda Lisa A. , Bonner Tom I. , Lolait Stephen J. 
Published: January 2005

AbstractCannabinoid receptor mRNA was localized in adult rat brain by 35S‐tailed oligonucleotide probes and in situ hybridization histochemistry. Labelling is described as uniform or non‐uniform depending on the relative intensities of individual cells expressing cannabinoid receptor mRNA within a given region or nucleus. Uniform labelling was found in the hypothalamus, thalamus, basal ganglia, cerebellum and brainstem. Non‐uniform labelling that resulted from the presence of cells displaying two easily distinguishable intensities of hybridization signals was observed in several regions and nuclei in the forebrain (cerebral cortex, hippocampus, amygdala, certain olfactory structures). Olfactory‐associated structures, basal ganglia, hippocampus, and cerebellar cortex displayed the heaviest amounts of labelling. Many regions that displayed cannabinoid receptor mRNA could reasonably be identified as sources for cannabinoid receptors on the basis of well documented hodologic data. Other sites that were also clearly labelled could not be assigned as logical sources of cannabinoid receptors. The localization of cannabinoid receptor mRNA indicates that sensory, motor, cognitive, limbic, and autonomic systems should all be influenced by the activation of this receptor by either exogenous cannabimimetics, including marijuana, or the yet unknown endogenous “cannabinoid” ligand. © 1993 Wiley‐Liss, Inc.
Development of the mesencephalic nucleus of the trigeminal nerve in chick embryos: Target innervation, neurotrophin receptors, and cell death
Authors: Von Bartheld Christopher S. , Bothwell Mark 
Published: January 2005

AbstractThe goal of this study was to determine whether processes of neurons in the mesencephalic nucleus of the trigeminal nerve (Mes V) of chick embryos arrive in their peripheral target prior to the period of developmental cell death, and to determine whether neurons with early target contact survive to a greater extent than neurons with processes that reach their peripheral target later. The arrival of Mes V nerve fibers in the masticatory muscles was determined by injecting the fluorescent tracer DiI, and the position of labeled and unlabeled neurons was mapped in subdivisions of the Mes V nucleus. Developmental changes in the numerical configuration of Mes V subdivisions were studied in DiI‐labeled as well as Nissl‐stained material. The expression of law‐affinity (p75) neurotrophin receptors was investigated throughout development of the Mes V nucleus with in situ hybridization to assess whether and how levels of expression of this trophic receptor may relate to target innervation and cell death. The extent of cell death was evaluated by counting pyknotic nuclei.Processes of Mes V neurons invade their peripheral target between 5 and 7 days of incubation (E5–7). At E7–12, between 800 and 1,400 labeled Mes V neurons were distributed throughout the two main subdivisions of the Mes V nucleus, the tectal commissure and the optic tectum. Only few Mes V neurons were labeled in the posterior commissure or outside the brain. Cell counts in Nissl‐stained material from E7–13 revealed that the numbers of Mes V neurons in the optic tectum decreased to about 40–60%, and in the tectal commissure to 20–25%, whereas Mes V neurons in the posterior commissure disappeared almost entirely. Few Mes V neurons remained in the leptomeninges at E8–10, but a considerable number was found outside the midbrain at E11, indicating ongoing migration of some Mes V neurons. Neurotrophin receptors were differentially expressed in the Mes V nucleus: Before and after the period of cell death, 90–100% of Mes V neurons expressed neurotrophin receptors, whereas during, and immediately preceding the period of developmental cell death (E9–E13), merely 70% of Mes V neurons expressed this receptor. These findings are consistent with the hypothesis that early target contact may provide an advantage for the survival of Mes V neurons and that competition for trophic factors may occur in the peripheral target of this nucleus prior to the period of cell death. © 1993 Wiley‐Liss, Inc.
Cholinergic innervation of the human cerebellum
Authors: de Lacalle Sonsoles , Hersh Louis B. , Saper Clifford B. 
Published: January 2005

AbstractCholinergic innervation of the human cerebellum was investigated immunocytochemically by using a polyclonal rabbit antiserum against choline acetyltransferase. Immunoreactive structures were found throughout the cerebellar cortex but were localized predominantly in the vermis, flocculus, and tonsilla. These included (1) a population of Golgi cells in the granular layer; (2) a subpopulation of mossy fibers and glomerular rosettes; (3) thin, varicose fibers closely associated with the Purkinje cell layer and the molecular layer; and (4) a relatively dense network of fibers and terminals contributing to the glomerular formations in the granular layer. In the cerebellar nuclei, some cells stained positively for choline acetyltransferase, and a terminal field pattern could be detected with a distinct but sparse network of varicose fibers. Acetylcholine appears to be a primary transmitter in the vestibulocerebellar pathways at several levels, which may account for the potent effects of muscarinic antagonists in diminishing vestibular vertigo in humans. © 1993 Wiley‐Liss, Inc.
Estimate of the total number of neurons and glial and endothelial cells in the rat spinal cord by means of the optical disector
Authors: Bjugn Roger , Gundersen Hans Jørgen G. 
Published: January 2005

AbstractThe total numbers of neurons and glial and endothelial cells in five rat spinal cords were estimated by stereological techniques.Each spinal cord was divided into 12 slabs of equal length. One transverse and one oblique slice was cut from each slab. The volumes of gray and white matter of each cord were then estimated by point‐counting techniques on the transverse slices. By means of optical disectors and systematic sampling, the numerical densities of different cell types were estimated on 35 m̈‐thick plastic sections from the oblique slices. The total cell number was calculated by multiplying the numerical density by the total volume of gray and white matter.On average there were 15.1 and 21.1 million cells in white and gray matter, respectively. Of the cells in gray matter, 6.4 million were judged to be neurons, 4.3 million to be endothelial, and 10.3 million to be glial. Of the neurons, 1.7 million were located in the cervical region, 2.5 million in the thoracic, 1.6 million in the lumbar, and 0.6 million in the sacro‐coccygeal region.The methods used are simple to perform, and the counting necessary to obtain a reliable estimate of cell number from one spinal cord can be carried out during the course of 1 day. The only major problem is reliable criteria for unambiguous cell classification. © 1993 Wiley‐Liss, Inc.
Possible morphological substrates for GABA‐mediated presynaptic inhibition in the lamprey spinal cord
Authors: Christenson Johan , Shupliakov Oleg , Cullheim Staffan , Grillner Sten 
Published: January 2005

AbstractGamma‐aminobutyric acid (GABA) neurons intrinsic to the lamprey spinal cord are known to modulate synaptic transmission from interneurons active during locomotion and from mechanosensory dorsal cells. Many of these physiological effects are presynaptic. To establish the morphological substrates for these axo‐axonic interactions, an ultrastructural analysis was performed with an antiserum to fixed GABA. The GABA immunoreactivity (ir) was detected by postembedding peroxidase‐antiperoxidase and immunogold techniques. GABA‐ir terminals were found to make appositions with unlabelled axons located in the dorsal columns and in the ventrolateral aspect of the spinal cord. In the ventrolateral part of the cord, similar appositions between different GABA‐ir terminals were also observed. The immunolabelled terminals contained spherical to pleomorphic synaptic vesicles, and also glycogen granules and dense core vesicles. In some cases, the fine structure of the contacts between immunogold‐labelled terminals and unlabelled axons suggested a synaptic relationship. Such a relation was found in a relatively small proportion (2–3%) of the appositions studied. These specializations were always observed in close relation to an output synapse of the postsynaptic axon. It is suggested that the axo‐axonal contacts described may provide an effective modulation of the synaptic transmission from axons in the lamprey spinal cord. © 1993 Wiley‐Liss, Inc.
The diencephalon of the pacific herring, Clupea harengus: Retinofugal projections to the diencephalon and optic tectum
Authors: Northcutt R. Glenn , Butler Ann B. 
Published: January 2005

AbstractThe pattern of retinofugal projections to nuclei in the diencephalon and to the optic tectum was analyzed with horseradish peroxidase and autoradiographic methods in Clupea harengus, a clupeomorph teleost, for comparison with osteoglossomorph, elopomorph, and euteleost teleosts and with non‐teleost actinopterygians. Most retinal fibers decussate in the optic chiasm and project to nuclei in the preoptic area, ventral and dorsal thalamus, posterior tuberculum, synencephalon, and pretectum, as well as to the accessory optic nuclei and optic tectum. Some ipsilateral projections do not decussate in the optic chiasm, while others decussate and recross via the supraoptic (minor) and posterior commissures. The pattern of projections is similar to that seen in other actinopterygian fishes with several exceptions. The terminal field usually present lateral to nucleus anterior in the dorsal thalamus is extremely reduced despite the relatively large size of the nucleus. A dense terminal field lies within the cell plate of nucleus corticalis in the pretectum rather than dorsal to it. The tectal hemisphere is composed of two distinct lobules, and the dorsal optic tract projects to the more rostromedial lobule while the ventral optic tract projects to the more caudolateral lobule. The lack of a significant projection to nucleus anterior and the lobular morphology of the optic tectum appear to be apomorphic for Clupea. Other features of the pattern of retinal projections are also analyzed in actinopterygian fishes including Clupea, and several hypotheses are advanced as to which traits are plesiomorphic for actinopterygians and/or for teleosts. © 1993 Wiley‐Liss, Inc.
Frequency organization of the dorsal cochlear nucleus in cats
Authors: Spirou George A. , May Bradford J. , Wright Debora D. , Ryugo David K. 
Published: January 2005

AbstractSensory epithelia are often spatially reiterated throughout their representation in the central nervous system. Differential expression of this representation can reveal specializations of the organism's behavioral repertoire. For example, the nature of the central representation of sound frequency in the auditory system has provided important clues in understanding ecological pressures for acoustic processing. In this context, we used electrophysiological techniques to map the frequency organization of the dorsal cochlear nucleus in nine cats. Frequency responses were sampled in increments of 100–200 μm along electrode tracks that entered the dosomedial border of the nucleus and exited at the ventrolateral border. Electrode tracks were oriented parallel to the long (or strial) axis of the nucleus so that each penetration sampled neural responses for most of the cat's audible frequencies and remained in or near the pyramidal cell layer for several millimeters. Nearly identical distance versus frequency relationships were obtained for different rostral‐caudal locations within the same cat as well as for different cats. Frequency responses systematically decreased from above 50 kHz at the most dorsomedial locations in the nucleus to below 1 kHz in the most ventrolateral regions. The rate of frequency change was roughly three times greater in high frequency regions than in low frequency regions. In addition, the highest pyramidal cell density and longest rostral‐caudal axis was observed for the middle third of the dorsal‐ventral axis of the nucleus. As a result, roughly half of all pyramidal cells responded to frequencies between 8–30 kHz. The representation of neural tissue for these frequencies may be related to the importance of spectral cues in sound localization. © 1993 Wiley‐Liss, Inc.
The catecholaminergic system of the quail brain: Immunocytochemical studies of dopamine β‐hydroxylase and tyrosine hydroxylase
Authors: Bailhache Thierry , Balthazart Jacques 
Published: January 2005

AbstractThe distribution of dopamine β‐hydroxylase and tryrosine hydroxylase, two key enzymes in the biosynthesis of catecholamine, was investigated by immunocytochemistry in the brain of male and female Japanese quail. Cells or fibers showing dopamine β‐hydroxylase and tyrosine hydroxylase immunoreactivity were considered to be noradrenergic or adrenergic, while all structures showing only tyrosine hydroxylase immunoreactivity were tentatively considered to be dopaminergic. The major dopaminergic and noradrenergic cell groups that have been identified in the brain of mammals could be observed in the Japanese quail, with the exception of a tuberoinfundibular dopaminergic group. The dopamine β‐hydroxylase‐immunoreactive cells were found exclusively in the pons (locus ceruleus and nucleus subceruleus ventralis) and in the medulla (area of the nucleus reticularis). The tyrosine hydroxylase‐immunoreactive cells had a much wider distribution and extended from the preoptic area to the level of the medulla. They were, however, present in larger numbers in the area ventralis of Tsai and in the nucleus tegmenti pedunculo‐pontinus, pars compacta, which respectively correspond to the ventral tegmental area and to the substantia nigra of mammals. A high density of dopamine β‐hydroxylase‐ and tyrosine hydroxylase‐immunoreactive fibers and punctate structures was found in several steroid‐sensitive brain regions that are implicated in the control of reproduction. In the preoptic area and in the region of the nucleus accumbens‐nucleus stria terminalis, immunonegative perikarya were completely surrounded by immunoreactive fiber forming basket‐like structures. Given that some of these cells contain the enzyme aromatase, these structures may represent the morphological substrate for a regulation of aromatase activity by catecholamines. The dopamine β‐hydroxylase‐immunoreactive fibers were also present in a larger part of the preoptic area of females than in males. This sex difference in the noradrenergic innervation of the preoptic area presumably reflects the sex difference in norepinephrine content in this region. © 1993 Wiley‐Liss, Inc.
Trigeminal nuclear complex of the ferret: Anatomical and Immunohistochemical studies
Authors: Boissonade Fiona M. , Sharkey Keith A. , Lucier Gregory E. 
Published: January 2005

AbstractIn order to establish the ferret as an animal model for studies of trigeminal pain, we describe the cytoarchitecture and neurochemistry of the trigeminal nuclear complex in the ferret and compare them to those of the cat and rat. The complex was divided as previously described, but the ferret differed in the extent of the nuclear boundaries. The neuroantomical distribution of substance P‐, calcitonin gene‐related peptide‐, galanin‐, enkephalin‐, serotonin‐, somatostatin‐, neuropeptide Y‐, and neurotensin‐immunoreactivity was determined throughout the rostrocaudal extent of the complex. In subnucleus caudalis, substance P‐, calcitonin gene‐related peptide‐, enkephalin‐, serotonin‐, somatostatin‐, neuropeptide Y‐, and galanin‐immunoreactivity was densest in laminae I and II. In subnucleus interpolaris, immunoreactivity for all the above neurochemicals was most dense along the lateral border and the ventral third of the caudal part of the subnucleus. Enkephalin‐immunoreactive cell bodies were present in subnucleus caudalis and interpolaris. In subnucleus oralis, labelling for substance P, calcitonin gene‐related peptide, galanin, enkephalin, and serotonin was most prominent in the dorsomedial part of the subnucleus. Somatostatin‐immunoreactive cell bodies were distributed throughout the spinal nucleus. Labelling of serotonin, substance P, calcitonin gene‐related peptide, galanin, enkephalin, and somatostatin was present in the main sensory nucleus. The motor nucleus contained fibers immunoreactive for substance P, enkephalin, serotonin and neuropeptide Y, and cell bodies immunoreactive for calcitonin gene‐related peptide. The majority of neurotensin‐immunoreactivity was found at the level of subnucleus caudalis, where it was densest in the trigeminal extension of the lateral cervical nucleus. The distribution of peptides in this species throughout the spinal nucleus is consistent with the notion that all the subnuclei may be involved in the processing of nociceptive inputs. © 1993 Wiley‐Liss, Inc.
Plasticity of auditory cortex associated with sensorineural hearing loss in adult C57BL/6J mice
Authors: Willott James F. , Aitkin Lindsay M. , McFadden Sandra L. 
Published: January 2005

AbstractThe representation of frequency was mapped in the primary auditory cortex (AI) of C57BL/6J (C57) mice during young adulthood (1.5–2 months) when hearing is optimal, and at 3, 6, and 12 months of age, a period during which progressive, high frequency, sensorineural hearing loss occurs in this strain. Maps were also obtained from CBA/CaJ mice which retain good hearing as they age.In AI of young adult C57 mice, and CBA mice, characteristic frequencies (CFs) of multiple‐unit clusters were easily identified with extracellular recordings, and a general tonotopic organization was observed from dorsal (high frequency) to ventral and caudal (low frequency). In individual cases there appeared to be deviations from the above tonotopic organization, despite the fact that inbred mice are genetically invariant. As progressive loss of high frequency sensitivity ensued peripherally, a substantially increased representation of middle frequencies was observed in AI. There was no apparent change in the surface area of the auditory cortex despite the elimination of high frequencies, and virtually the entire auditory cortex became devoted to the middle frequencies (especially 10–13 kHz) for which sensitivity remained high. Similar age‐related changes were not observed in normal‐hearing CBA mice. These findings indicate that plasticity in the representation of frequency in AI is associated with high frequency hearing loss in C57 mice. © 1993 Wiley‐Liss, Inc.
Segmental arrangement of reticulospinal neurons in the goldfish hindbrain
Authors: Lee Robert K. K. , Eaton Robert C. , Zottoli Steven J. 
Published: January 2005

AbstractThe hindbrain is evolutionarily conserved among diverse vertebrate phyla. In vertebrate embryos, the hindbrain is segmentally organized as a series of overt swellings known as rhombomeres. In the larval zebrafish Brachydanio rerio, conspicuous and identifiable reticulospinal neurons are positioned in the center of rhombomeres. Segmentally homologous reticulospinal neurons that share a range of morphological, developmental, and biochemical features occupy adjacent rhombomeres.We have recently shown that reticulospinal neurons of the zebrafish survive ontogeny without considerable morphological modification and we suggested that homologous neurons may share similar functions at different stages of development (Lee and Eaton: Journal of Comparative Neurology 304:34–52, 1991). The goldfish Carassius auratus, a related cyprinid, is especially suited for neurophysiological and behavioral studies. However, it is not yet known if the various reticulospinal neurons of zebrafish are generalizable to other species such as the goldfish. Therefore, we sought to examine the extent to which reticulospinal neurons of the zebrafish are also present in the adult goldfish.Analysis of 45 brains retrogradely labeled with horseradish peroxidase (HRP) from the spinal cord showed that reticulospinal neurons are arranged as a series of seven segments within the hindbrain; a regular interval of approximately 200 μm separates adjacent segments. Although the goldfish reticulospinal system has more neurons than the zebrafish, many reticulospinal neuron types continue to be identifiable. Moreover, comparisons of dendritic arborizations and axon paths between the two species showed that the morphology between various neuron types is virtually identical. The cross‐taxonomic similarities between the reticulospinal systems of these related cyprinids make it possible to pursue functional considerations of segmentally homologous neurons in the goldfish hindbrain. © 1993 Wiley‐Liss, Inc.
Architectionis, somatotopic organization, and ipsilateral cortical connections of the primary motor area (M1) of owl monkeys
Authors: Stepniewska Iwona , Preuss Todd M. , Kaas Jon H. 
Published: January 2005

AbstractThe ipsilateral cortical connections of primary motor cortex (M1) of owl monkeys were revealed by injecting WGA‐HRP and fluorescent tracers into M1 sites identified by intracortical microstimulation. In some of the same animals, the extent and somatotopic organization of M1 was determined by making detailed microstimulation movement maps and relating the results to cortical architectonics. Thus, delineation of M1 was based on a combination of physiological and anatomical characteristics. M1 comprised most, but not all, of the cortex rostral to area 3a where movements were evoked at low levels of current (40 μA or less). Analysis of somatotopic patterns and architectonics placed some of the low‐threshold sites in a ventral premotor field (PMV) and the dorsomedially situated supplementary motor area (SMA). Movements were also reliably elicited from a dorsal premotor area (PMD) at higher currents. M1 was characterized by a somatotopic global organization, representing hindlimb, trunk, forelimb, and face movements in a mediolateral sequence, and a mosaic local organization, with a given movement typically represented at several different sites. Architectionically, M1 was characterized by the absence of a granular layer IV and the presence of very large layer V pyramidal cells. However, M1 was not uniform in structure: pyramidal cells were larger caudally than rostrally, a feature we used to distinguish caudal (M1c) and rostral (M1r) subdivisions of the area. M1 resembles Brodmann's area 4, although the rostral subdivision has probably been considered as part of area 6 by some workers. Tracer injections of M1 revealed somatotopically distributed connections with motor areas PMD, PMV, and SMA, as well as in somatosensory areas 3a, 1, 2, and S2. Weaker connections were with area 3b, posterior parietal cortex, the parietal ventral area (PV), and cingulate cortex. M1r and M1c differed connectionally as well as architectonically, M1c being connected primarily with somatosensory areas, while M1r was strongly connected with both non‐primary motor cortex and somatosensory cortex. These results indicate that M1 interacts directly with at least three non‐primary motor areas and at least six somatosensory areas.