bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of D1 and D2 dopamine receptors in the basal ganglia of the cat determined by quantitative autoradiography
Authors: Beckstead R. M. , Wooten G. F. , Trugman J. M. 
Published: January 2005

AbstractThe patterns of dopamine D1 and D2 receptors were examined in the corpus striatum and related structures in the cat brain by quantitative autoradiography after in vitro radioligand binding with [3H]SCH23390 (D1 antagonist) and [3H]spiperone (D2 antagonist). Highly specific binding for both radioligands occurs in striatal structures known to receive dopaminergic input: the caudate nucleus, putamen, nucleus accumbens, and olfactory tubercle. However, the density of binding varies from one structure to another, and the density distribution within striatal nuclei is heterogeneous. In all but one portion of the striatum, the concentration of bound D1 radioligand ranges from 46 to 230% more than that of the D2 radioligand. The exception to this difference occurs at caudal putamenal levels where the two radioligands bind in equal concentrations. (≈︁ 220 fmol/mg tissue wet‐weight). The highest density of both D1 and D2 radioligand binding occurs in irregular zones in the head and body of the caudate nucleus. Such high‐density zones of D2 radioligand binding appear mainly in the dorsolateral part of the caudate's head. For the D1 radioligand, the high‐density zones are more widespread throughout the caudate nucleus, nucleus accumbens, and putamen. The D2 radioligand binding (but not the D1) also exhibits low‐density zones at more caudal levels of the caudate nucleus, and these are often in register with the high‐density zones of D1 radioligand binding. In the putamen, inverted concentration gradients, exist for the two radioligands: the [3H]SCH23390 gradient runs from higher levels rostrally to lower levels caudally. The lowest levels of bound [3H]spiperone in the striatum occur in the nucleus accumbens‐olfactory tubercle area, whereas the lowest binding of [3H]SCH23390 occurs in the caudal putamen.Pallidal and nigral structures show marked disparities in binding of the two different radioligands. The D2 radioligand binding in the globus pallidus (80 ± 8 fmol/mg tissue wet‐weight) is about twice that in the entopeduncular nucleus and pars reticulata of the substantia nigra, the latter two having equal levels (35 ± 3 fmol/mg). No specific binding of the D2 radioligand occurs in the ventral pallidum. In contrast, D1 radioligand binding is highest in the entopeduncular nucleus (217 ± 6 fmol/mg) and in the pars reticulata of the substantia nigra (198 ± 2 fmol/mg) and moderate in the ventral pallidum (135 ± 15 fmol/mg). In the globus pallidus, no detectable D1 radioligand binding occurs. The binding density of [3H]SCH23390 is comparable in both subdivisions of the substantia nigra, but [3H]spiperone binding is four times greater in the pars compacta (154 ± 12 fmol/mg) than in the pars reticulata. The heterogeneity of dopamine receptors is discussed with respect to other evidence for compartmentation in the striatum and the neurochemical organization of the striatopallidal projection system.
Corticothalamic connections of paralimbic regions in the rhesus monkey
Authors: Yeterian Edward H. , Pandya Deepak N. 
Published: January 2005

AbstractThis study addressed the issue of whether paralimbic regions of the cerebral cortex share common thalamic projections. The corticothalamic connections of the paralimbic regions of the orbital frontal, medial prefrontal, cingulate, parahippocampal, and temporal polar cortices were studied with the autoradiographic method in the rhesus monkey. The results revealed that the orbital frontal, medial prefrontal, and temporal polar proisocortices have substantial projections to both the dorsomedial and medial pulvinar nuclei, whereas the anterior cingulate proisocortex (area 24) projects exclusively to the dorsomedial nucleus. These proisocortical areas also have thalamic connections with the intralaminar and midline nuclei. The cortical areas between the proisocortical regions on the one hand and the isocortical areas on the other, that is, the posterior cingulate region (area 23) and the posterior parahippocampal gyrus (areas TF and TH), project predominantly to the dorsal portion of the medial pulvinar nucleus, the anterior nuclear group (AV, AM), and the lateral dorsal (LD) nucleus. Additionally, the posterior cingulate and medial parahippocampal gyri (area TH) have projections to the lateral posterior (LP) nucleus.Thus, it appears that the proisocortical areas, which are characterized by a predominance of infragranular layers and an absence of layer IV, have common thalamic relationships. Likewise, the intermediate paralimbic areas between the proisocortex and isocortical regions, which also have a predominance of infragranular layers but in addition have evidence of a fourth layer, project to the medial pulvinar and to the so‐called limbic nuclei, AV, AM, LD, as well as a modality‐specific nucleus, LP.
Morphology of the caudal spinal cord in Rana (ranidae) and Xenopus (pipidae) tadpoles
Authors: Nishikawa Kiisa , Wassersug Richard 
Published: January 2005

AbstractUsing a variety of neuroanatomical and histological techniques, we compare the spinal cord and peripheral nerve distribution in the tails of larvae from Xenopus laevis and three species of Rana.The relatively large, postsacral spinal, cord of Xenopus contains abundant motoneurons and their axons. Spinal nerves exit from the spinal cord in a regular array, one nerve per myotome, from the cervical region to near the end of the tail. Somata of motoneurons innervating caudal myotomes are found along the entire length of the tail. In contrast, the caudal cord of Rana is reduced to a filum terminate consisting of little more than an ependymal tube; spinal nerves to all caudal myotomes leave the cord in the sacral region and reach their motor targets via a cauda equina and caudal plexus. Motoneuron cell bodies innervating caudal myotomes are found only in the sacral region.The Rana larval pattern is similar to that of adult frogs and mammals, whereas the Xenopus larval pattern is more like that of salamanders and reptiles. These gross neuroanatomical differences are not due to differences in the size or developmental stage of the tadpoles, but instead are associated with differences in the swimming behavior of the larvae.The presence of motoneurons in the caudal spinal cord of Xenopus may provide local intermyotomal control within the tail; the elongated topography of the cord appears to permit finer, rostral‐to‐caudal regulation of neuromuscular activity. The Rana spinal cord, on the other hand‐with motoneurons clustered anteriorly‐may produce concurrent firing of adjacent ipsilateral myotomes, but at the expense of fine intermyotomal regulation. The fact that nerves in the tail of Xenopus enter and exit from the spinal cord locally, as opposed to far anteriorly as in Rana, means that for tadpoles of the same size, reflex arc lengths are many times shorter in Xenopus.
Sexual differences in the development of accessory olfactory bulbs in the rat
Authors: Roos J. , Roos M. , Schaeffer C. , Aron C. 
Published: January 2005

AbstractThe aim of this investigation was (1) to compare the development of AOB in male and female rats before birth, early after birth, and at later stages of sexual immaturity and maturity (2) to examine the effects of early and delayed castration after birth on AOB development in the male rat. A significant increase of the surface area of AOB was observed in both sexes from birth until postnatal day 7, but AOB was found to be larger in males than in females. From the end of the first postnatal week AOB stopped growing until day 40 in both males and females. After this time AOB resumed its development until day 60 in males, while no changes occurred in females over the same period. Castration of males at birth or six hours later impaired development of AOB. Castration of males on postnatal days 20 or 30 also impaired AOB development until day 60.The results strongly suggest that the development of AOB in the male rat is dependent on the two well known “perinatal” and “adult” phases of the endocrine activity of the testes.
Ultrastructural visualization of primate cone photoreceptor matrix sheaths
Authors: Blanks Janet C. , Hageman Gregory S. , Johnson Lincoln V. , Spee Christine 
Published: January 2005

AbstractGlycoconjugates, including glycolipids, glycoproteins, and proteoglycans, are present in the plasma membrane of photoreceptor cells and in the interphotoreceptor matrix surrounding photoreceptor cell ellipsoids and outer segments. Although the precise function of these molecules is unknown, they may be important in mediating photoreceptor–pigment epithelial cell interactions, outer segment membrane assembly, and/or disc shedding. Lectins, affinity ligands for defined carbohydrate sequences, have proven particularly useful in studying the glycoconjugate composition of the interphotoreceptor matrix. The peanut lectin selectively binds to domains of the interphotoreceptor matrix surrounding cone (“cone matrix sheaths”), but not rod inner and outer segments. This is evidence for the existence of chemical and structural heterogeneity within the interphotoreceptor matrix.The studies described herein utilized ultrastructural pre‐embedding histochemical labeling to assess whether, in addition to the surrounding interphotoreceptor matrix, peanut lectin binding is associated directly with the plasma membrane of cone inner and outer segments. This study confirms that ferritin‐conjugated peanut agglutinin binds to cone matrix sheaths, and, in addition, provides ultrastructural evidence for the presence of binding to the plasma membrane surrounding cone inner and outer segments. The data suggest that cone membrane–associated peanut agglutinin–binding molecules may differ from those located within cone matrix sheaths.
Origin of ascending projections to an isofrequency region of the mustache bat's inferior colliculus
Authors: Ross Linda S. , Pollak George D. , Zook John M. 
Published: January 2005

AbstractThe inferior colliculus of the mustache bat is similar in most respects to the inferior colliculus of more commonly studied mammals, but one isofrequency contour, the dorsoposterior division, is greatly overrepresented. The present study utilizes this specialization of the auditory system in the mustache bat to determine the total set of ascending projections to a single isofrequency contour of the inferior colliculus. Within the dorsoposterior division, neurons are all very narrowly tuned to 60 kHz, the major component of this bat's echolocation call. The afferent projections to this isofrequency contour were identified by making deposits of horseradish peroxidase (HRP) within the dorsoposterior division after physiologically defining its borders. Two other frequency representations are present in the central nucleus of the inferior colliculus of the mustache bat, the anterolateral division in which there is an orderly progression of frequencies from 59 down to 20 kHz, and the medial division in which frequencies from 63–120 kHz are represented. In additional experiments, the afferent projections to the medial and anterolateral divisions were examined, providing an anatomical description of the tonotopicity of the lower auditory nuclei.Deposits of HRP in the DPD labeled cells in each of the lower brainstem auditory nuclei that have previously been shown to project to the entire central nucleus of the inferior colliculus. The ascending projections to the dorsoposterior division include contralateral projections from the cochlear nucleus and inferior colliculus, ipsilateral projections from the medial superior olive, ventral and intermediate nuclei of the lateral lemniscus, and bilateral projections from the lateral superior olive and dorsal nucleus of the lateral lemniscus. In most of the nuclei, labeled cells were confined to specific portions of the nuclei, often forming “slabs” of labeled cells across the rostrocaudal extent of most nuclei. These slabs presumably represent the 60 kHz representation in each of the lower nuclei. When deposits of HRP were made into other frequency band representations of the inferior colliculus, in either the medial or anterolateral division, labeled cells again formed slabs in each lower nucleus. However, the location of the slab varied as a function of the best frequency of neurons at the deposit site, and labeled cells were not present within the 60 kHz representation. These results show the general tonotopy of the mustache bat's brainstem auditory nuclei, and with respect to the dorsoposterior division, clearly reveal the total set of projections to a single isofrequency region. In addition, results are presented that suggest that some nuclei project to restricted areas of the dorsoposterior division.
Topographical relationship between the entorhinal cortex and the septotemporal axis of the dentate gyrus in rats: II. Cells projecting from lateral entorhinal subdivision
Authors: Ruth Russell E. , Collier Timothy J. , Routtenberg Aryeh 
Published: January 2005

AbstractProjections from the rat lateral entorhinal cortex (area 28‐l) to the dentate gyrus were traced and then interpreted according to a parcellation scheme that recognized four cytoarchitectonic subdivisions of area 28‐1: areas dorsolateral (dl), ventrolateral (vl), ventromedial (vm), and TR. Following lesions of area 28‐l, anterograde degeneration was traced with the Fink‐Heimer method. In parallel experiments iontophoretic injections of horseradish peroxidase (HRP) were made in the lateral perforant path terminal zone of the dentate molecular layer. Retrograde neuronal labeling patterns within area 28‐l were charted following dorsal, midseptotemporal (mid ST), and ventral dentate injections. In two additional cases HRP was deposited in the ventral subiculum.Lesions of area dl (which lies entirely on the posterolateral cortex) produced terminal degeneration that was confined to the dorsal one‐half of the dentate gyrus. Lesions involving primarily areas vl and vm (which lie on the posteroinferior cortex) caused a complementary pattern of degeneration; silver grains predominated in the ventral dentate gyrus.Injections of HRP into the outer dentate molecular layer labeled layer II neurons within area 28‐l. Deposits of HRP in the dorsal one‐third of the dentate gyrus labeled a rostrocaudal strip of neurons within the dorsal one‐third of area dl; no other subdivisions of area 28vl contained labeling. After mid‐ST deposits of HRP, a rostrocaudally oriented strip of labeled cells appeared in the ventral one‐third of area dl. Mid‐ST injections also labeled neurons in the caudolateral quadrant of area vl. Injection of HRP into the ventral dentate gyrus labeled neurons in the caudomedial quadrant of area vl as well as a few neurons in caudal area vm. No labeled cells were ever found in area dl following ventral dentate HRP deposits. Neurons within area TR were never retrogradely labeled from injections of HRP into the dentate perforant path zone. However, ventral subicular injections of HRP labeled a few cells in the posterior part of area TR, as well as hundreds of neurons throughout the rostrocaudal extent of area vl.The results indicate a highly organized innervation of the dentate gyrus by several subdivisions of area 28‐l. In area dl, rostrocaudal strips of layer II neurons innervate distinct segments of the dorsal ST axis. The posterior half of areas vl and vm innervates the ventral half of the ST axis; a lateromedial gradient there corresponds to increasingly ventral terminations along the dentate ST axis. Finally, in contrast to the other lateral entorhinal subdivisions area TR does not appear to innervate the distal dendrites of dentate granule cells. The implications of this organization for the study of functional diversity along the ST axis are considered.
Afferent connections of the sexually dimorphic area of the hypothalamus of male and female gerbils
Authors: De Vries Geert J. , Gonzales Cathleen L. , Yahr Pauline 
Published: January 2005

AbstractWe studied neural inputs to the sexually dimorphic area (SDA) of the gerbil hypothalamus by injecting wheat‐germ agglutinin‐horseradish peroxidase into its medial or lateral components in males and females. To confirm the topography of SDA afferents, we injected Phaseolus vulgaris‐leucoagglutinin into areas where retrograde labeling from the medial and lateral SDA differed. Both methods indicated that the medial SDA received stronger inputs from the medial part of the bed nucleus of the stria terminalis, the ventral part of the lateral septal nucleus, the medial amygdaloid nucleus, and the amygdalohippocampal area, than the lateral SDA does. In contrast, the rostrodorsal part of the lateral septum, the lateral part of the bed nucleus of the stria terminalis, the anterior and posterior hypothalamic areas, and the dorsomedial hypothalamic nucleus project more heavily to the lateral than to the medial SDA. In addition, retrograde labeling suggested that the ventral part of the premammillary nucleus projects more strongly to the medial than to the lateral SDA, whereas the infralimbic area of the cortex and the lateral preoptic area project more strongly to the lateral than to the medial SDA. The densities of cells in the bed nucleus of the stria terminalis and medial amygdaloid nucleus that could be retrogradely labeled from the medial SDA were greater in males than in females. This was not true of labeling in the arcuate nucleus or in the ventral part of the lateral septal nucleus. Since the medial SDA receives strong inputs from areas with many steroid‐accumulating cells, it could respond to steroids directly and via these afferents. In contrast, hormonal effects on the lateral SDA are more likely to occur locally.
Distribution of dopamine immunoreactivity in the forebrain and midbrain of the snake Python regius: A study with antibodies against dopamine
Authors: Smeets Wilhelmus J. A. J. 
Published: January 2005

AbstractThe distribution of dopamine (DA) immunoreactivity in the forebrain and midbrain of the ball python, Python regius, was studied by using recently developed antibodies against DA. In order to determine general and species‐specific features of the DA system in reptiles, we have selected the ball python as a representative of a reptilian radiation that hitherto has not been the subject of (immuno)histochemical studies.Dopamine‐containing cell bodies were found around the glomeruli and in the external plexiform layer of both the main and accessory olfactory bulb, but not in the telencephalon proper. In the diencephalon, DA cells were observed in several parts of the periventricular hypothalamic nucleus, in the periventricular organ, the ependymal wall of the infundibular recess, the lateral hypothalamic area, the magnocellular ventrolateral thalamic nucleus, and the pretectal posterodorsal nucleus. In the midbrain, DA cells were found in the ventral tegmental area, the substantia nigra, and the presumed reptilian homologue of the mammalian A8 cell group.Dopaminergic fibers and varicosities were observed throughout the whole brain, particularly in the telencephalon and diencephalon. The nucleus accumbens, striatum, olfactory tubercle, and nucleus of the accessory olfactory tract appear to have the most dense innervation, but the lateral septal nucleus, the dorsal ventricular ridge, and the nucleus sphericus also show numerous DA‐containing fibers and varicosities. Except for the lateral cortex, cortical areas are not densely innervated by DA fibers.The DA system of the snake Python regius shares many features with that of lizards and turtles as determined with the same antibodies. The taxonomically close relationship between lizards and snakes, which together constitute the Squamata, is reflected in a similar distribution of DA fibers and varicosities to the dorsal ventricular ridge and the lateral cortex, and in the limited number of CSF‐contacting DA neurons in the hypothalamus.
Cerebral arterial innervation by nerve fibers containing calcitonin gene‐related peptide (CGRP): I. Distribution and origin of CGRP perivascular innervation in rat
Authors: Tsai Shin‐Han. , Tew John M. , McLean John H. , Shipley Michael T. 
Published: January 2005

AbstractThe origin, density and distribution of calcitonin gene‐related peptide (CGRP) immunoreactivity in cerebral perivascular nerves and the trigeminal ganglion of rats were examined in this study. CGRP immunoreactive axons were abundant on the walls of the rostral circulation of the major cerebral arteries in the circle of Willis. The fibers form a grid‐ or meshwork of longitudinal and circumferential axons studded with numerous varicose swellings. The density of CGRP fibers was particularly high at the bifurcation of major arteries. A few CGRP fibers cross the midline to innervate arteries on the contralateral side of the arterial tree. The arteries of the caudal circulation were sparsely innervated by CGRP fibers.In the trigeminal ganglion, about 30% of the ganglion cells had CGRP immunoreactivity. The cell size of most (75%) of CGRP neurons was less than 30 μm in diameter. There was no significant difference in staining density between small and large CGRP neurons. Unilateral transection of the maxillary and mandibular divisions of the trieminal nerve caused a substantial decrease of CGRP immunoreactivity in the ipsilateral dorsal two‐thirds of te trigeminal nucleus and cervical spinal cord but did not noticeably change the diameter of the vascular lumen or the densities of CGRP fibers in the walls of te cerebral arteries. In contrast, unilateral on the ipsilateral cerebral arteries and eliminated CGRP immunoreactivity throughout the trigeminal nucleus in the brainstem and rostral cervical cord. In addition, tese lesions caused a significant reduction in the diameter of the denervated arteries.The present study demonstrates that CGRP, a putative neurotransmitter/neuromodulator, is especially abundant in the rostral cerebral circulation and is derived from the ipsilateral ophthalmic division of the trigeminal nerve. In addition, the loss of CGRP perivascular nerves is associated with a reduction of the arterial lumen. This suggests that CGRP is a strong candidate as a nerve‐derived trophic factor at trigeminal terminals and provides additional evidence that CGRP is a component in te trigeminovascular system influenceing vascular diameter.