bluuebunny/crossref_metadata_2025_split huggingface dataset:
Convergence of autonomic and limbic connections in the insular cortex of the rat
Authors: Saper Clifford B. 
Published: December 2004

AbstractThe connnections of the insular cortex in the rate were studied by using the anterograde and retrograde transport of wheat germ agglutinin‐conjugated‐horseradish peroxidase. Both anterograde and retrogrde transport were seen in the ipsilateral lateral frontal, infralimbic, piriform, and perirhinal cortical areas and in the contralateral insular cortex. In the thalaamus, both types of labeling were seen in the mediodorsal and ventroposteromedial parvocellular nuclei; primarily retrograde labeling was seen in the centromedial and paracentral nuclei. In the basal forebrain, anterograde labeling was seen in the lateralpart of the bed nucleus of the stria terminalis and in the central nucleus of the amygdala, while retrogradely labeled neurons were found in the magnocellular basal nucleus and in the lateral and basolateral amygdaloid nuclei. Both types of labeling were seen in the posterior lateral hypothalamic area; the tuberomammillary nucleus contained retrogradely labeled neurons bilaterally. In the midbrain, retrogradely labeled neurons were found in the ventral tegmental area and in the dorsal and superior central raphe nuclei. In the pons, both retrogradely and anterogradely transported label was seen bilaterally in the parabrachial nucleus, primarily in the ventromedial caudal part of the medial subnucleus. Retrogradely labeled neurons were found bilaterally in the locus coeruleus. Anterograde transport was followed into the medulla, bilaterally but more heavily in the contralateral side. Labeled axons appeared to terminate in a topographic pattern in the nucleus of the solitary tract.These results indicate that the insular cortex of the rat is an important part of the highly interconnected central autonomic system. Furthermore, the autonomic representation in the insular cortex may be organized in a viscerotopic manner. The insular cortex also has connections with the limbic system and with the lateral frontal cortical system. Although it is not yet clear whether these connections converge upon the same neurons within the insular cortex, earlier physiological data suggest that each of the diverse systems of connections of this area receives relayed vagal inputs. The insular cortex of the rat may contain a primary cortical visceral representation, and its connections may underlie autonomic integration with behavioral and emotional events.
Cell death of motoneurons in the chick embryo spinal cord. VI. Reduction of naturally occurring cell death in the thoracolumbar column of terni by nerve growth factor
Authors: Oppenheim Ronald W. , Maderdrut Jerome L. , Wells David J. 
Published: December 2004

AbstractA discrete preganglionic cell column (column of Terni, CT) in the caudal thoracolumbar (segments 21–23) spinal cord is first discernible in avian embryos on day 8 when it contains approximately 9,300 visceral motoneurons. By day 10 there are about 6,900 motoneurons in the thoracolumbar (sympathetic) CT and this number remains constant until at least day 15. Daily injections of nerve growth factor (NGF) (1–20 μg) on the chorioallantoic membrane from day 3 to day 9 produced a dose‐dependent increase in both the volume of the caudal thoracolumbar sympathetic ganglia and the number of motoneurons in the corresponding CT on day 10. The number and size of the neurons in the paravertebral sympathetic ganglia was also increased by NGF. Nerve growth factor decreased the number of pyknotic (dying) neurons in both the thoracolumbar sympathetic ganglia and the corresponding CT on days 8 and 10. The increased number of neurons in both the thoracolumbar sympathetic ganglia and the corresponding CT following chronic administration of NGF is the result of decreased cell death. The highest dose of NGF reduced naturally occurring cell death in the thoracolumbar CT by more than 60%. Daily injections of cytochrome C (20 μg) from day 3 to day 9 had no effect on either the volume of the sympathetic ganglia or the number of motoneurons in the CT on day 10Daily injections of NGF (10–20 μg) from day 10 until day 14 increased the volume of (and the number of neurons in) the caudal thoracic sympathetic ganglia on day 15 but had no effect on the number of motoneurons in the corresponding CT. Nerve growth factor also had no effect on the number of motoneurons in either the somatic lateral motor column, the sacral (parasympathetic) CT, or the “abortive” visceral efferent column at the cervical level. Daily administration of NGF produced a similar increase in the volume of the dorsal root ganglia at the cervical, thoracic, and sacral levels. The reduction of cell death in the thoracolumbar CT by NGF is the result of neither a direct effect on spinal motoneurons nor an indirect effect of increased sensory innervationNaturally occurring cell death of sympathetic preganglionic neurons is regulated by the size of their innervation field.
An afoveate area centralis in the chick retina
Authors: Morris Valerie B. 
Published: December 2004

AbstractA specialization has been found in the nasal retina of late embryonic and newly hatched chicks of the domestic fowl. In whole mounts of the retina, there is a central node about 2 mm from the dorsal end of the optic disc and a set of structures radiating out from this node. This complex has been named the aster. sections of the retina show that the structures which form the aster lie in the inner nuclear layer. The specialization has been classed as an afoveate area centralis.
Histochemical evidence for sympathetic innervation of hair receptor afferents in cat skin
Authors: Roberts William J. , Levitt Gregg R. 
Published: December 2004

AbstractThe goal of the present study was to demonstate histochemically fine catecholamine‐containing sympathetic nerve fibers which might be associated with hair receptor afferent fibers in cat skin. Positive results would be consistent with the hypothesis that the sympathetically mediated desensitization of hair afferents, observed in this and earlier studies, is mediated by direct neurotransmitter release onto the afferent fibers.Activity in single primary afferent fibers was recorded electrophysiologically during mechanical stimulation of hairs and electrical stimulation of the lumbar sympathetic trunk in anesthetized cats. The mechanical threshold for activation was seen to increase markedly during low‐frequencey sympathetic stimulation.Fresh‐frozen sections of skin from cat hindleg were treated with glyoxylic acid for detection of fluorescent catecholamines. Fluorescent fibers were observed in association with hair follicles as well as with arterioles and arrector‐pili muscles. Subsequent silver staining of the identical skin sections revealed that the fine catecholamine‐containing fibers located near hair follicle were closely associated with hair receptor afferent fibers. The results are therefore consistent with the hypothesis that sympathetic modulation of hair receptor sensitivity is mediated by direct neurotransmitter release onto the afferent fibers.
Neurotensin: Topographical distribution of brain sites involoved in hypothermia and antinociception
Authors: Kalivas Peter W. , Jennes Lothar , Nemeroff Charles B. , Prange Arthur J. 
Published: December 2004

AbstractWhen administered into the cerebroventricular system of the rat, neurotensin (NT) produces a variety of effects, including a decrease in colonic temperature and an increase in nociceptive threshold. The previous study described in detail the localization of immunohistochemical NT in the rat brain. In this study, bilateral injections of NT were made into 223 separate loci in the rat brain and a map was generated showing the brain regions where NT produced a decline in colonic temperature and an increase in hot plate response latency. It was found that some of the brain areas which contain immunohistochemically identified NT responded to locally administered NT. Further, most NT‐sensitive brain loci contain NT cell bodies as well as fibers.Areas in the brain where NT produced an antinociceptive response were not the same areas where NT evoked hypothermia. An antinociceptive response was consistently produced after NT injection into the nucleus amygdaloideus centralis, rostral area praeoptica medialis, the ventral thalamus dorsomedial and medial to the lemniscus medialis, rostal mesencephalic periventricular gray, and medial pontine formatio reticularis. Less‐consistent antinociception was also observed in the mesencephalic formatio reticularis and the caudal diagonal band of Broca. Hypothermia was induced by NT in the area praeoptica medialis contiguous with the area anterior hypothalami, nucleus ventralis tegmenti (Tasi), floor of the fourth ventricle, and tractus spinalis nervi trigemini. Less profound hypothermia was also produced in the posterior hypothalamus. The fact that all these responsive brain areas contain NT indicates that the microinjection of NT may be mimicking the effects of endogenously released NT, thus supporting the possible physiological significance of NT as an endogenous modulator of body temperature or nociceptive sensory information.
The accessory motor nuclei of the trigeminal, facial, and abducens nerves in the rat
Authors: Székely George , Matesz Clara 
Published: December 2004

AbstractThe cobalt labeling technique was applied to the trigeminal, facial, and abducens roots in order to investigate the location and morphology of motoneurons of the main and accessory motor nuclei of these cranial nerves in the rat. On the basis of soma‐dendritic morphology, axonal trajectory, and tegmental location, three different accessory nuclei were distinguished in the brainstem. Neurons of the accessory nuclei of V and VII form a common club‐shaped nucleus extending between the main motor nuclei of V and VII. The Dendritic tree of these neurons is oriented in the dorsoventral direction and the axon invariably follows a dorsolaterally directed bent course. The accessory VI nucleus is located ventral and lateral to the main VI nucleus in the lateral tegmentum. The neurons have elongated perikarya, strong ventral and weak dorsal dendritic arbors, and the bent axonal course is directed dorsomedially. Neurons of the main VI nucleus have rounded perikarya and radial dendritic arborizations. Muscle groups innervated by the accessory and main motor nuclei have distinctly different functions.
An HRP study of the connections of the subfornical organ of the rat
Authors: Lind R. Wallace , van Hoesen Gray W. , Johnson Alan Kim 
Published: December 2004

AbstractThe connections of the subfornical organ (SFO) wer investigated by using the HRP technique. Injections into the SFO labeled neurons in the medial septum, but not in lateral septum nor in the diagonal band nucleus. Labeled cells were observed in the median preoptic nucleus, below the ependyma of the third ventricle, in the dorsal preoptic region near the anterior commissure, and diffusely throughout the medial preoptic and anterior bypothalamic areas.Fibers were followed from the ventral stalk of the SFO. Precommissural fibers enter the median preoptic nucleus where many of them appear to terminate. Others continue on to the medial septum, the OVLT, the supraoptic nucleus, and the suprachiasmatic nucleus, HRP injections into the median preoptic nucleus labled many neurons in the SFO.Postcommissural fibers reach the hypothalamus by descending along the walls of the ventricle in the subependymal space, by traveling in the columns of the fornix and the medial corticohypothalamic tract, or by passing through the paraventricular nucleus of the thalamus. Some postcommissural fibers turn rostrally and enter the median preoptic nucleus while others join precommissural fibers bound for the supraoptic nucleus. More caudally directed fibers appear to innervate the paraventricular nucleus of the hypothalamus and the medial preoptic and anterior hypothalamic areas. HRP injections into the paraventricular nucleus of the hypothalamus labeled neurons in the SFO.These finding corroborate and extend previous work in describing neural connections between two brain regions that are important for fluid blance.
The afferent connections of the suprachiasmatic nucleus of the golden hamster with emphasis on the retinohypothalamic projection
Authors: Pickard Gary E. 
Published: December 2004

AbstractThe afferent connections of the hypothalamic suprachiasmatic nucleus (SCN) of the golden hamster were examined using horseradish peroxidase (HRP) as the retrograde tracer molecule. Unilateral iontophoretic deposition of HRP into the SCN labeled ganglion cells bilaterally in the retinae. The labeled ganglion cells all had large somata and were randomly distributed across the retina. A similar number were labeled in each retina, which contrasted with the findings from injections into the optic chiasm and lateral geniculate body. Chiasm and geniculate injections both labeled three classes of ganglion cell (small, large, and giant) predominantly in the contralateral retinae.Telencephalic afferent projections to the SCN included the ventral subicular cortex and the septum. Notable diencephalic afferents included the dorsal lamina of the internal division of the ventral lateral geniculate nucleus (vLGN); the ipsilateral input was twice that of the contralateral projection. The same region of the vLGN was also noted to be reciprocally connected to the contralateral vLGN. The thalamic paraventricular nucleus was also heavily labeled but only ipsilaterally. Of functional significance, the SCN was discovered to innervate its contralateral homologue. Other less numerous afferents in the midbrain included the dorsal and median raphe nuclei and the dorsal nucleus of the lateral lemniscus.The afferent projections to the SCN determined in this study are discussed in regard to the known physiological role of the SCN as part of the circadian clock system.
Somatotopic organization of vibrissae afferents in the trigeminal sensorynuclei of the rat studied by transganglionic transport of HRP
Authors: Arvidsson Jan 
Published: December 2004

AbstractTransganglionic transport of horseradish peroxidase (HRP) has been used to study the cell bodies and central projections of neurons innervating the vibrissae in the rat. These can be grouped into five horizontal rows and one posterior vertical row. Twenty‐four to 48 hours after the nerves innervating different vibrissae were exposed to HRP, the trigeminal ganglia, brainstem, and upper cervical spinal cord were fixed by perfusion and serial sections were processed according to the tetramethylbenzidine technique.The results revealed a tendency for somatotopic organization in the trigeminal ganglion of cell bodies innervating the different vibrissae. Corresponding termination areas in the trigeminal sensory nuclei showed a detailed pattern of organization replicating the peripheral organization of the vibrissae. In all trigeminal sensory nuclei the horizontal rows are represented in an inverted fashion from dorsal to ventral, i.e., the most dorsal row is represented most yentrally. In addition, the more anterior a vibrissa is located, the deeper is it represented in the rostral nonlaminated nuclei. The situation is reversed in the laminated nucleus caudalis. The posterior vertical row is represented most superficially in the rostral nonlaminated nuclei, but most deeply in the laminated nucleus caudalis. In nucleus cau dalis there are also rostrocaudal differences in the representation of differ ent vibrissae. Thus, the posterior vibrissae in a horizontal row have their main representations more caudally than the anterior vibrissae. The pos terior vertical row has its main representation most caudally, in the Cl segment.
Cortical connections of striate cortex in the owl monkey
Authors: Lin C.‐S. , Weller R. E. , Kaas J. H. 
Published: December 2004

AbstractInjections of trkiated proline and horseradish peroxidase were used to study cortical connections of striate cortex in owl monkeys. All cases resulted in label in area 18 (V‐II) and the middle temporal visual area (MT). In most, but not all cases, label was also present in the dorsomedial visual area (DM). The connections between striate cortex and each of these three visual areas were retinotopic and reciprocal. Projections to V‐II, MT, and DM were concentrated in layers IV and III, while pyramidal cells in layers III, V, and VI of these areas projected back to striate cortex.
Functional role of regrowing pyramidal tract fibers
Authors: Reh Thomas , Kalil Katherine 
Published: December 2004

AbstractWhen pyramidal tract axons are severed in the infant hamster, the damaged fiber? regrow via a new pathway to their normal terminal sites in the medulla and spinal cord and there form synaptic connections (Kalil and Reh, ′79, ′82). We studied the behavior of animals with infant and adult lesions of the medullary pyramid to determine the functional significance of the new pathway in maintaining normal motor behavior. Examination of behaviors normally mediated by the pyramidal tract, particularly the manipulation of sunflower seeds during feeding, revealed a correlation between the presence of the new tract and the preservation of function. Furthermore, in the adult animal with an infant lesion, the spared behaviors were lost when the new pathway was destroyed.
Exposure to lines of only one orientation modifies dendritic morphology of cells in the visual cortex of the cat
Authors: Tieman Suzannah Bliss , Hirsch Helmut V. B. 
Published: December 2004

AbstractTo determine whether selective exposure to lines of one orientation modifies the shape of the dendritic fields of cells in visual cortex, we examined the dendritic morphology of neurons in area 17 of five normally reared cats, five cats reared viewing only vertical lines, and three cats reared viewing only horizontal lines. Kittens were placed with their mothers into a totally dark room before their eyes had opened. Beginning at 4 weeks of age, the kittens were brought out for daily periods of exposure wearing masks that limited the vision of each eye to a field of three vertical lines or three horizontal lines. After a minimum of 170 hours of exposure, the animals were killed and blocks of visual cortex were impregnated by the Golgi‐Kopsch procedure and cut tangential to the pial surface. Complete neurons from layers III and IV were drawn with the aid of a camera lucida, and the orientations of the dendritic fields were analyzed using Sholl diagrams. In normal cats, the distributions of the orientations of dendritic fields were uniform, whereas in stripe‐reared cats, the distributions for the layer III pyramidal cells were shifted. The direction of this shift varied with the experience of the cat: In cats reared viewing only vertical lines, the dendritic fields were oriented orthogonal to the representation of the vertical meridian, and in cats reared viewing only horizontal lines, the fields were oriented parallel to the representation of the vertical meridian. In contrast, the distribution of dendritic orientations for the stellate cells was not affected by stripe‐rearing. These results demonstrate a morphological effect of early visual experience that is specific to the particular stimulus presented during rearing and suggest that (1) cortical cells differ in the degree to which they can be modified by such experience, and (2) the dendritic morphology of cortical neurons is related to their preferred orientations.
A horseradish peroxidase study of projections from the main and external cuneate nuclei to the cerebellum of the North American raccoon
Authors: Haring John H. , Rowinski Mark J. 
Published: December 2004

AbstractNeurons of the raccoon main (MCN) and external (ECN) cuneate nuclei having terminal fields in the anterior lobe and paramedian lobule of the cerebellum were studied by means of the retrograde transport of horseradish peroxidase (HRP). In the MCN, neurons of the polymorphic regions, but not of the round cell clusters, were labeled following HRP injections of the anterior lobe. HRP‐labeled fusiform, triangular, and stellate cells were observed from 3–4 mm caudal to the obex to 2–3 mm rostral to it. The main body of labeled MCN neurons was located in the 1.25 mm immediately rostral to the obex, there forming a recognizable subnucleus in the ventral MCN. The ECN displayed uniform labeling from the anterior lobe with no particular cell type or nuclear region being labeled preferentially. A minor projection to the anterior lobe appeared to originate in the contralateral MCN and ECN. Injections of the paramedian lobule produced MCN labeling similar to that observed after anterior lobe injections, but the majority of labeled ECN neurons were found in the dorsomedial part of the nucleus.In lobule V of the anterior lobe, sagittal zone c contained the greatest density of cuneocerebellar terminals as judged by the degree of retrograde labeling seen in neurons of both the MCN and ECN. This observation was consistent with evoked potentials recorded in the anterior lobe of the raccoon cerebellum.The position of cuneocerebellar neurons in the ventrolateral MCN suggests that the bulk of the information being transferred to the cerebellumby the raccoon MCN is related to deep, rather than cutaneous, modalities.
An electron microscopic comparison of the medial interlaminar nucleus and the a laminae in the dorsal lateral geniculate nucleus of the cat
Authors: Wilson James R. 
Published: December 2004

AbstractThe medial interlaminar nucleus (MIN) of the cat's dorsal lateral ge‐niculate nucleus was studied under the light and electron microscopes and compared with the A laminae. At the light level, MIN has more axons and a lesser cell packing density than the A laminae. Examined at the electron microscopic level, MIN could not qualitatively be distinguished from the A laminae. When quantitative counts of the profiles containing synaptic ves‐icles were made, MIN had less F profiles and more RSD profiles per unit area than the A laminae. Structure/function correlations suggest that additional F terminals may mediate nondominant eye inhibition and/or a greater amount of inhibition on X‐cells versus Y‐cells.