bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metamorphosis of spinal‐projecting neurons in the brain of the sea lamprey during transformation of the larva to adult: Normal anatomy and response to axotomy
Authors: Swain Gary P. , Ayers Joseph , Selzer Michael E. 
Published: January 2005

AbstractThe spinal projecting system of the sea lamprey (Petromyzon marinus) has been used extensively in studies of axonal regeneration in both larvae and adults. However, little is known about the changes that are undergone by this system during metamorphosis. In order to determine the developmental changes in the size of the descending spinal projection and in the morphology of its neurons, larval, transforming, and adult lamprey brains were labeled by retrograde transport of horseradish peroxidase (HRP) injected into the spinal cord at 25% of body length. Examination of brain wholemount preparations revealed that the total number of labeled neurons doubled during metamorphosis. Most of this increase could be explained by elongation of reticulospinal axons from the rostralmost segments of the spinal cord to locations caudal to the injection site. There were no additions or deletions of either identified reticulospinal neurons or of reticulospinal nuclear groups between the larval and the adult stages. The proportions of Müller and Mauthner cells that were labeled reached a maximum of 93% during the early stages of metamorphosis. Axons of these neurons are known to project almost the entire length of the cord, even in larvae. Therefore, the efficiency of retrograde transport appears to be greater during metamorphosis than during larval or adult stages. While changes in efficiency of retrograde transport could account for some of the apparent increase in reticulospinal neuron numbers between larvae and animals undergoing metamorphosis, this could not contribute to the further increase in the apparent size of the reticulospinal system in the adult, since efficiency of retrograde labeling in these animals was lower than that at earlier stages. With retrograde labeling, a significant increase was seen in the profusion of dendritic arborization of some Müller and Mauthner cells during the early stages of metamorphosis. This correlated with an increase in the incidence of extreme axonal die‐back, as indicated by the presence of retraction bulbs within the brainstem. However, intracellular injection of Neurobiotin in untransected animals showed similar degrees of dendritic arborization at all examined stages of development. Therefore, the dendritic profusion did not reflect developmental changes in neuronal morphology but rather reflected an increased sensitivity to axotomy during metamorphosis. We conclude that, during the transformation of the lamprey from the large larval to the adult form, there is little change in either the size or the dendritic morphology of the identified giant reticulospinal neurons. With respect to the smaller reticulospinal neurons, the distance of projection of many of their axons increases during metamorphosis, but there is very little increase in the number of reticulospinal neurons. © 1995 Wiley‐Liss Inc.
Laminar patterns of expression of GABAA receptor subunit mRNAs in monkey sensory motor cortex
Authors: Huntsman M. M. , Woods T. M. , Jones E. G. 
Published: January 2005

AbstractRadioactive complementary RNA probes, made from monkey‐specific cDNAs specific for the α1, α2, α4, α5, β1, β2, and γ2 and γ2 subunits of the γ‐aminobutyric acid A (GABAA) receptor were used for in situ hybridization histochemistry of the primary motor, somatosensory, and anterior parietal areas of thecerebral cortex in macaque monkeys.mRNAs for the α1, β2, and α2, subunit polypeptides, which form receptors with the full range of classical properties, are expressed at much higher levels in all areas and show laminar and sublaminar‐specific concentrations. α2, α4, α5, and β1 subunit transcripts are expressed at much lower levels but also display individual, laminar‐specific concentrations; α5, expression, in particular, is highly expressed in layer IV in the somatosensory and parietal areas and in a layer IV‐like band in the motor cortex.In layers in which expression of a particular transcript is high, all neurons may express the gene, but in layers in which expression is moderate, it is possible to detect differences in the degree of labeling of individual neurons for a particular mRNA, and some neurons may not express certain subunit transcripts in detectable amounts.These findings indicate the variability in expression of different GABAA receptor subunits in the cerebral cortex. Laminar differences may indicate the assembly of functional receptors from different arrangements of available subunits in different classes of cells. © 1995 Wiley‐Liss Inc.
Ultrastructural basis for synaptic transmission between jaw muscle spindle afferents and trigeminothalamic neurons in the rostral trigeminal sensory nuclei of the rat
Authors: Luo Pifu , Wong Richard , Dessem Dean 
Published: January 2005

AbstractTrigeminothalamic neurons were retrogradely labeled by injection of horseradish peroxidase into the ventroposteromedial nucleus of the thalamus in rats. Jaw‐muscle spindle afferent axons were then physiologically identified and intracellularly stained with biotinamide. The ultrastructure of labeled spindle afferent boutons was then studied in the caudolateral supratrigeminal region (Vsup) and dorsomedial trigeminal principal sensory nucleus (Vpdm). A total of 418 stained spindle afferent boutons were identified in Vsup and Vpdm; approximately 75% of these synapsed with dendrites, 10% synapsed with somata, and 15% synapsed with axons. Most jaw‐muscle spindle afferent boutons were postsynaptic to unlabeled P‐type boutons. Reciprocal synapses between spindle afferent boutons and unlabeled boutons were occasionally observed. A few dendrites in Vsup and Vpdm received synapses from multiple spindle afferent boutons. Conversely, some large (from 3 × 6 to 4 × 8 μm) and giant (from > 4 × 8 to 5 × 10 μm) spindle afferent boutons simultaneously contacted two to five dendrites and/or somata. Jaw‐muscle spindle afferent boutons also formed synapses with retrogradely labeled trigeminothalamic neurons in Vsup and Vpdm. Numerous unlabeled S‐and F‐type boutons converged onto the same trigeminothalamic dendrite or soma contacted by a spindle afferent bouton. A small number of synaptic triads consisting of an unlabeled P‐type bouton, a spindle afferent bouton, and either a dendrite or soina were also encountered. These data indicate that sensory feedback from the masticatory muscles is subject to presynaptic inhibition and integration prior to reaching the thalamus. This pathway is likely to be important in the relay of proprioceptive and kinesthetic information from the muscles of mastication to the thalamus. © 1995 Wiley‐Liss, Inc.
Morphological and functional effects of intranigrally administered GDNF in normal rhesus monkeys
Authors: Gash Don Marshall , Zhang Zhiming , Cass Wayne A. , Ovadia Aliza , Simmerman Linda , Martin David , Russell Deborah , Collins Frank , Hoffer Barry J. , Gerhardt Greg A. 
Published: January 2005

AbstractEffects of a single injection of either 150 μg human recombinant glial cell line‐derived neurotrophic factor (rGDNF) or vehicle into the right substantia nigra were analyzed in 12 normal adult female rhesus monkeys. The studies included evaluating whole animal behavior, electrochemical recordings of striatal dopamine release, neurochemical determinations of basal ganglia and nigral monoamine levels, and immunohistochemical staining of the nigrostriatal dopamine system. The behavioral effects over the 3–week observation period following trophic factor administration were small, with blinded observers unable to distinguish between GDNF and vehicle‐treated animals. Quantitative measurements did show that five of six trophic factor recipients experienced some weight loss and four of the six GDNF recipients displayed small, but significant, increases in daytime activity levels. In vivo electrochemical recordings in the ipsilateral caudate and putamen 3 weeks after GDNF administration revealed increased potassium‐evoked release of dopamine in trophic factor recipients. In a second series of animals killed at the same time, dopamine levels in the substantia nigra and ventral tegmental area of GDNF recipients were significantly increased, with ipsilateral values more than 200% higher than contralateral and control levels. Levels of the dopamine metabolite HVA were significantly elevated in the substantia nigra, ventral tegmental area, and caudate nucleus ipsilateral to the trophic factor injection. There was a trend toward increased HVA levels in the ipsilateral putamen, nucleus accumbens, and globus pallidus in GDNF‐treated animals, but the ratios of HVA to dopamine were not significantly different between vehicle‐ and GDNF‐treated recipients. Although some tissue damage from the delivery of concentrated trophic factor was evident, dopamine neurons remained in and adjacent to the injection site. In the substantia nigra ipsilateral to GDNF administration, dopamine‐neuron perikaryal size was significantly increased, along with a significant increase in tyrosine hydroxylase‐positive axons and dendrites. We conclude that, in the adult rhesus monkey, a single intranigral GDNF injection induces a significant upregulation of mesencephalic dopamine neurons which lasts for weeks. © 1995 Wiley‐Liss, Inc.
Projections from visual areas of the cerebral cortex to pretectal nuclear complex, terminal accessory optic nuclei, and superior colliculus in macaque monkey
Authors: Lui Fausta , Gregory Kenneth M. , Blanks Robert H. I. , Giolli Roland A. 
Published: January 2005

AbstractThe purpose of this study was to analyze the projections from visually related areas of the cerebral cortex of rhesus monkey to subcortical nuclei involved in eye‐movement control; i. e., the pretectal nuclear complex, the terminal nuclei of the accessory optic system (AOS), and the superior colliculus (SC). The anterograde tracer 3H‐leucine was pressure injected bilaterally into the cortex of six monkeys (for a total of 12 cases) involving the primary visual cortex (area 17); the medial prestriate cortex (medial 18/19), dorsomedial area 19; the caudal portion of the cortex of the superior temporal sulcus, upper bank (cytoarchitectural area OAa) and lower bank (area PGa); the lower bank of the caudal lateral intraparietal sulcus (area POa); and the inferior parietal lobule (area 7).The results revealed that the pretectal nucleus of the optic tract received inputs from medial prestriate cortex, dorsomedial part of area 19, OAa, and PGa. The posterior pretectal nucleus received sparse projections from area 7 and the cortex lining the intraparietal sulcus (dorsomedial part of area 19 and POa). The pretectal olivary nucleus was targeted by neurons in cortex of dorsomedial arec 19, and the anterior pretectal nucleus was targeted by neurons in both dorsomedial 19 and area 7.The nuclei of the AOS (dorsal terminal; lateral terminal; and interstitial nuclei of the superior fasciculus, posterior and medial fibers) received projections exclusively from areas OAa and PGa. Furthermore, in one case with PGa injection, the medial terminal nucleus, dorsal portion, was also labeled.The visual cortical areas studied projected differentially upon the SC laminae. The primary visual area 17 projected only to the superficial laminae, i. e., stratum zonale (SZ), stratum griseum superficiale (SGS), and stratum opticum (SO). On the other hand, the medial portion of the prestriate cortex and caudal OAa and PGa targeted the superficial and intermediate laminae, i. e., SZ, SGS, SO, stratum griseum intermediale (SGI), whereas caudal area POa projected primarily to the intermediate layer SGI. Rostral area 7 (mainly 7b) neurons terminated in the stratum album intermediale (SAI); no SC terminals were found in a case in which caudal area 7 (mainly 7a) was injected. © 1995 Wiley‐Liss, Inc.
Immunocytochemical localization of Diploptera punctata allatostatin‐like peptide in Drosophila melanogaster
Authors: Yoon Jae G. , Stay Barbara 
Published: January 2005

AbstractAllatostatins isolated from the cockroach Diploptera punctata are a family of neuropeptides that inhibit juvenile hormone synthesis in cockroaches and related insects but not in flies. In cockroaches, these widely distributed peptides have been shown to have other functions. This report provides evidence for the presence of allatostatin‐like peptides in Drosophila melanogaster by demonstration of allatostatic activity of extracts of central nervous system from larvae and adults on corpora allata of Diploptera and by immunocytochemical localization of peptides in Drosophila with monoclonal antibody against Diploptera allatostatin I. Extract of adult central nervous system showed four times more allatostatic activity than that of the larva or twice the activity per unit volume of central nervous system. This is reflected in an increase in number and arborization of immunoreactive neurons in the adult. The immunoreactive neurons in the central nervous system appear to be interneurons, with the exception of motoneurons in the last abdominal neuromere that project to muscles of the hindgut, a pair of peripheral cells in each of two thoracic segments in the larva and on nerves to wings and halteres in the adult, and endocrine cells of the midgut epithelium. Nerves to the corpus allatum were not immunoreactive. The presence of Diploptera allatostatin‐like peptides in interneurons and motoneurons, in the neurohemal networks, and in endocrine cells of the midgut and their absence in nerves to the corpus allatum in Drosophila suggests that these peptides may function as neuromodulators, myomodulators, and neurohormones and not as regulators of the corpus allatum. © 1995 Wiley‐Liss, Inc.
Intracerebroventricular kainic acid administration in adult rat alters hippocampal calbindin and non‐phosphorylated neurofilament expression
Authors: Shetty Ashok K. , Turner Dennis A. 
Published: January 2005

AbstractCalbindin and non‐phosphorylated neurofilament proteins were assessed in hippocampus following a unilateral intracerebroventricular kainic acid injection at 4, 26, and 60 days post‐lesion, using immunocytochemical expression. The density of calbindin‐positive non‐ pyramidal neurons throughout the hippocarnpus showed no significant alteration at 4 days post‐lesion, a significant decrease at 26 days post‐lesion, and a partial recovery at 60 days post‐lesion. In addition, calbindin immunoreactivity was dramatically reduced at 26 days post‐lesion in the CA1 pyramidal and dentate granule cell layers and the mossy fibers, bilaterally. Although not significant statistically, most of these reductions showed signs of reversal at 60 days post‐lesion except the CA1 pyramidal cell layer where the dramatic reductions persisted. Neurofilaments were also altered throughout the post‐lesion period, particularly in abnormal expression of non‐phosphorylated neurofilament proteins in mossy fibers. The apparent return of calbindin immunoreactivity in non‐pyramidal neurons by 60 days post‐lesion suggests that recovery from the lesion may involve remaining neuronal elements which either become reactivated with time or have the capability to express normal levels of calbindin with re‐innervation. On the other hand, prolonged calbindin reductions in superficial CA1 pyramidal cells suggest sustained down‐regulation of calbindin expression owing to persistent reductions in the activity of these neurons. The temporal correlation of the expression of non‐phosphorylated neurofilamenta in mossy fibers with their sprouting response following target loss suggests a potential role for non‐phosphorylated neurofilaments in neuronal plasticity involving axonal sprouting. Alternatively, it may also suggest that injury‐ induced neurofilament modifications are either conducive or permissive for axonal sprouting. © 1995 Wiley‐Liss, Inc.
A note on the significance of the small volume of the nerve cell bodies in the cerebral cortex in man
Authors: Donaldson Henry H. 
Published: January 2005

Abstract
The weight of all the nerve cell bodies in the human encephalon is less than 27 grams.
When comparison is made of human encephala grouped according to race, sex, mental power, stature and age, the differences in weight, within each group, are always more than twice that of the nerve cell bodies, and hence these differences depend mainly on variations in the medullary substance
Small variations in the mass of the nerve cell bodies (though physiologically highly important) escape detection by the method of weighing, or may be masked by the greater growth of the medullary substance.
Saccharin‐taste discrimination by two‐lever choice: A rat bioassay for sweeteners
Authors: Shearman Gary T. , Cafaro Michael P. , Lal Harbans , Howard James L. 
Published: January 2005

AbstractMale hooded rats were trained to discriminate the taste of a saccharin solution from that of water by responding with a lever on one side of a food cup following 20 licks (500 μl) of a 0.002 M saccharin solution and responding with a lever on the alternate side following 20 licks (500 μl) of water for food reinforcement. All of the rats learned this discrimination reliably. The gustatory stimulus produced by saccharin was concentration‐dependent. Sucrose (0.01–0.1 M) and dextrose (0.1–0.5 M) produced a concentration‐dependent generalization to the saccharin taste. Solutions of sodium chloride (0.15 M), citric acid (0.01 M), caffeine citrate (0.01 M), and quinine hydrochloride (0.00001–0.01 M) did not produce saccharin‐like taste. Generalization of sweet compounds and lack of generalization of salty, sour, and bitter compounds to the saccharin taste suggest that discrimination of the nonnutritive sweetener, saccharin, by the rat may possibly be used as a bioassay to detect and quantitate the sweetening property of new compounds.
Correlation of behavioral and neurochemical effects of d‐ and l‐amphetamines
Authors: Aulakh C. S. , Bhattacharyya A. K. , Pradhan S. N. 
Published: January 2005

AbstractIn an attempt to correlate the behavioral and neurochemical effects of d‐ and l‐amphetamines, the time courses of the effects of the two isomers (1 mg/kg; base, i.p.) were studied on spontaneous motor activity (SMA) and stereotyped behavior (ST) as well as on the concentrations of norepinephrine (NE), dopamine (DA), and serotonin (5‐HT) in discrete brain areas, such as the caudate nucleus (CN), pons‐medulla (PM), and diencephalonmidbrain (DM) in rats. In addition, the dose‐response relationship for d‐isomer (0.5–2 mg/kg, i.p.) and l‐isomer (1–4 mg/kg, i.p.) was also studied on SMA and ST. SMA increased with the dose up to 1.5 mg/kg for d‐isomer and up to 3 mg/kg for l‐isomer and then decreased, whereas ST increased with the dose for both the isomers. At 1 mg/kg dose, SMA reached its peak during the fourth postdrug 20–minute period for both d‐ and l‐isomers, whereas ST reached its peak during third to fifth 20‐minute periods for d‐isomer and during the third period for the l‐isomer. The d‐isomer significantly increased the DA levels in the CN and DM at 30 minutes postdrug, which reached their maximum at 60 minutes, whereas NE levels in the PM had no significant change at 30 minutes, but were significantly reduced in the DM at 30 minutes and in both PM and DM at 60 minutes postdrug; 5‐HT levels in the PM and DM showed no significant change. Compared to d‐amphetamine, the l‐isomer at 30 and 60 minutes postdrug caused more or less similar changes in the NE levels in the DM and PM, whereas it produced less increase in the DA levels in the CN and DM and significant decrease in 5‐HT levels in the DM and PM. It appears that the difference in the behavioral effects induced by the two isomers of amphetamine may be due to the difference in their effects on dopaminergic and serotonergic systems.
Glucocorticoid regulation of lung beta‐adrenergic receptors
Authors: Scarpace Philip J. , Abrass Itamar B. 
Published: January 2005

AbstractTo test the hypothesis that glucocorticoids modulate lung beta‐adrenergic receptors as a mechanism for their therapeutic effect in asthma, we investigated the effects of adrenalectomy and glucocorticoid administration on rat lung beta‐adrenergic receptors. The data demonstrate that, compared to untreated animals, adrenalectomized Sprague‐Dawley rats treated with cortisol (80 mg/kg) for 5 days and nonoperated rats treated with methylprednisolone (100 mg/kg) for 5 days have a 30% increase in lung beta‐adrenergic receptors, as measured by [3H]‐dihydroalprenolol binding. These data support the hypothesis that pharmacological doses of glucocorticoids modulate lung beta‐adrenergic receptors upwards. This mechanism may account, at least in part, for the therapeutic effect of these drugs in asthma.
Effect of cyproterone acetate and conjugated estrogens on the human insulin receptor
Authors: De Pirro Roberto , Forte Fiorella , Liberti Marcello , Gallucci Michele , Monaco Fabrizio , Lauro Renato 
Published: January 2005

AbstractIt has recently been reported that prednisone increases whereas dexamethasone and cortisone decrease insulin binding to monocytes, thus suggesting that different steroids may exert opposite effects on the insulin receptor, depending on their chemical structure. In order to gain further insight into the modulations of the insulin receptor by other steroids, the effect in male patients of short‐ and long‐term oral treatment with cyproterone acetate (100–150 mg/day) or conjugated estrogens (20 mg/day) was evaluated. Cyproterone acetate did not produce any statistical, evident change in insulin binding to monocytes after either short‐term (5 days) or long‐term (1 year) treatment. Short‐term (5 days) administration of conjugated estrogens did not affect insulin binding; however, long‐term (1 year) treatment produced a highly significant decrease in insulin binding due mainly to changes in receptor concentration. Thus, cyproterone acetate does not affect the insulin receptor, whereas conjugated estrogens reduce insulin receptors after long‐term treatment, as with dexamethasone and cortisone.Estrogens probably play a role in the insulin binding impairment which occurs during the luteal phase of the menstrual cycle as well as in users of the “pill”.
Midbrain‐renal dopaminergic axis and control of venous capacitance: Pathological and therapeutic significance in hypertension
Authors: Osborne Melville W. , Kovzelove Francis 
Published: January 2005

AbstractAcute intravenous infusion of methyldopa in anesthetized normotensive dogs produced a hemodynamic profile which indicates that the decrease in arterial blood pressure occurs secondary to venous pooling. The methyldopa‐mediated venous pooling is blocked by prior treatment with indomethacin. Both acute administration of methyldopa and L‐dopa mediate venous pooling from the midbrain as reactivity to the carotid occlusion reflex is intact. The venous pooling occurs in the cutaneous venous capacitance bed. Chronic treatment with methyldopa causes venoconstriction with a secondary increase in cardiac output. The venoconstriction is accompanied by a significant decrease in plasma renin activity without any effect on plasma aldosterone secretion, cortisol secretion, or serum electrolytes (Na+, K+, Cl−). Renal denervation abolished both the chronic methytldopa venoconstriction and endocrine effects; only venodilation was evident. Chronic treatment with L‐dopa caused only venodilation with a significant increase in plasma aldosterone secretion, but without an effect on plasma renin activity, cortisol secretion, or serum electrolyte values. The primary neuroeffector in the kidney which communicates with the midbrain venomotor center appears to be mediated by a prostaglandins. It is postulated that the alterations in plasma renin activity and aldosterone secretion reported in this investigation are mediated by the brain isorenin‐angiotensin system since alterations in plasma renin activity and aldosterone secretion do not occur in parallel, cortisol secretion is not altered, and the blood pressure‐pressor response to angiotensin I and II is not blocked.