bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anuran dorsal column nucleus: Organization, immunohistochemical characterization, and fiber connections in Rana perezi and Xenopus laevis
Authors: Muñoz A. , Muñoz M. , González A. , Donkelaar H. J. Ten 
Published: January 2005

AbstractAs part of a research program on the evolution of somatosensory systems in vertebrates, the dorsal column nucleus (DCN) was studied with (immuno) histochemical and tract‐tracing techniques in anurans (the large green frog, Rana perezi, and the clawed toad, Xenopus laevis). The anuran DCN contains some nicotinamide adenine dinucleotide phosphate diaphorase positiye neurons, very little calbindin D‐28k, and a distinct parvalbumin‐positive cell population. The anuran DCN is innervated by primary and non‐primary spinal afferents, by primary afferents from cranial nerves V, VII, IX, and X, by serotonin‐immunoreactive fibers, and by peptidergic fibers. Non‐primary DCN afferents from the spinal cord appear to arise throughout the spinal cord, but particularly from the ipsilateral dorsal gray. The present study focused on the efferent connections of the DCN, in particular the targets of the medial lemniscus. The medial lemniscus could be traced throughout the brainstem and into the diencephalon. Along its course, the medial lemniscus gives off collaterals to various parts of the reticular formation, to the octavolateral area, and to the granular layer of the cerebellum. At mesencephalic levels, the medial lemniscus innervates the lateral part of the torus semicircularis as well as various tegmental nuclei. A striking difference between the two species studied is that while in R. perezi medial lemniscal fibers do not reach the tectum mesencephali, in X. laevis intermediate and deep tectal layers are innervated. Beyond the midbrain, both dorsal and ventral thalamic areas are innervated by the medial lemniscus. The present study shows that the anuran “lemniscal pathway” is basically similar to that of amniotes. © 1995 Wiley‐Liss, Inc.
Structural and functional characterization of a muscle tendon proprioceptor in lobster
Authors: Combes Denis , Simmers John , Moulins Maurice 
Published: January 2005

AbstractA morphological and electrophysiological study was made on a unique primary mechanosensory neuron, the anterior gastric receptor (AGR), previously shown to arise from powerstroke muscle gm1 of the gastric mill system in the lobster foregut. Ultrastructural analysis of horseradish peroxidase injected AGR demonstrated that its peripheral dendrites do not ramify in muscle but are confined strictly to the connective tissue/epidermal interface in the tendon of gm1. These terminals are rich in mitochondria and at their very endings are free of glial cell wrapping, suggesting that they are the site at which mechanotransduction occurs. Extracellular axonal recordings from an in vitro neuromuscular preparation consisting of the gm1 muscle still attached to the stomatogastric nervous system, revealed that AGR is activated by passive stretch of gm1. The response to ramp stimuli displays dynamic and static components, both of which increase with the amplitude of applied stretch, while the dynamic component is also velocity sensitive. AGR is also activated by muscle contraction here elicited either by application of exogenous acetyicholine, the excitatory neurotransmitter for gm 1, or by electrical stimulation of the motoneurons (GM) themselves. Consistent with a receptor lying in‐series with its muscle, therefore, the effective stimulus of AGR in vivo is probably an increase in tension exerted on the tendon during active muscle contraction. In neuromuscular preparations including the bilateral commissural ganglia, stretching gm1 reflexly activates GM motoneurons at low stimulus strengths but leads to an inactivation of GM motoneurons at high stimulus strengths. This is consistent with earlier findings that both responses can be elicited by direct electrical stimulation of AGR. The functional implications of AGR's anatomical relationship with muscle gm 1, the receptor's response properties, and its central effeet8 on motor output to gm1 are discussed. Comparison is also drawn between this first reported example of a true tendon receptor in invertebrates and muscle receptors of vertebrates. © 1995 Wiley‐Liss, Inc.
Morphogenesis of the photoreceptive site and development of the electrical responses in the butterfly genital photoreceptors during the pupal period
Authors: Miyako Yumiko , Arikawa Kentaro , Eguchi Eisuke 
Published: January 2005

AbstractThis paper describes the process of morphogenesis of the photoreceptive site of the butterfly genital photoreceptors. Associated development of the electrical responses is also described. The photoreceptor is a sensory neuron whose cell body is located in the genitalia and has a photoreceptive site of the phaosome‐type. This consists of the distal processes and the tubular membranes, which protrude from the tip of distal processes.Phaosome morphogenesis was studied using electron microscopy. The results indicate that morphogenesis occurs in the latter half of the pupal period and that the process is divided into five phases. First, the tubular membranes appear as small membrane protrusions (phase I). The short tubular membranes emerge from several portions of the cell body forming several membrane clusters (phase II). The clusters then collect to form a small phaosome. Short distal processes become evident (phase III). The phaosome volume increases, mainly due to the extensive elongation and bifurcation of both tubular membranes and distal processes (phase IV). Phase V achieves fii adult morphology. The photoreceptors of phase II are already able to produce spikes in response to light stimulation, although the sensitivity was about one tenth of the adult. The sensitivity increase occurred in parallel with the increase in the phaosome volume. © 1995 Wiley‐Liss, Inc.
Serotonergic innervation of the lateral geniculate nucleus of the rat during postnatal development: A light and electron microscopic immunocytochemical analysis
Authors: Dinopoulos A. , Dori I. , Parnavelas J. G. 
Published: January 2005

AbstractThe serotonergic innervation of the developing lateral geniculate nucleus of the rat was studied with immunocytochemical techniques at the light and electron microscope levels. A relatively small number of thick serotonergic fibers were observed at the time of birth, distributed more densely in the ventral portion of the nucleus and in the intergeniculate leaflet than in the dorsal lateral geniculate nucleus. By the end of the first postnatal week, this distribution pattern was more clearly established, but the number of immunoreactive fibers was increased. Thereafter, and until the adult pattern was estabiished at the end of the third postnatal week, serotonergic fibers increased further in number and changed morphologically (e. g., they became finer and more ramified with closely spaced varicosities), but their pattern of distribution remained unchanged.Electron microscopical analysis of the dorsal lateral geniculate nucleus revealed that the vast majority of serotonin varicosities formed asymmetrical synapses with dendritic shafts; axosomatic synapses were a feature of the nucleus only at the time of birth. The proportion of serotonin varicosities forming synapses increased gradually from birth to reach a peak at the end of the second post week, then declined markedly in the following week before increasing again at a later stage. It may be speculated that synapses formed during the first two weeks of life may be related to the involvement of serotonin in the morphogenesis of the lateral geniculate nucleus, whereas those formed later in development may be involved in the mediation of neurotransm effects. © 1995 Wiley‐Liss, Inc.
Observations on the weight and length of the central nervous system and of the legs in frogs, of different sizes (Rana virescens brachycephala– cope)
Authors: Donaldson Henry H. , Schoemaker Daniel M. 
Published: January 2005

Abstract
The males of Rana virescens brachycephala rarely attain a body weight above 50 grms. The females (without ovaries) may weigh 75 grams or more.When the average of the largest males is compared with females yielding the same average weight, the males are found to have the lighter brain and spinal cord.
Spring frogs tend to lose weight rapidly when kept in the laboratory. This tendency diminishes as the season advances toward autumn.
In Rana virescens brachycephala the relative weight of the brain compared to that of the spinal cord decreases as the frog increases in size.
The weight of the leg muscles compared with the weight of the entire frog increases in small frogs up to about 5 grms. of body weight and then slightly decreases as the frog increases in size. In individuals of all sizes, the muscles of the thigh weigh from 1.78 to 1.80 times as much as those of the rest of the leg.
In frogs of all sizes, the sum of the lengths of the leg bones is a nearly constant fraction of the length of the entire frog. The proportional lengths of the several bones are also nearly constant.
Inhibition of prostaglandin synthesis by topically applied flurbiprofen in human primary irritant dermatitis
Authors: Kassis Vibeke , Søndergaard Jørgen 
Published: January 2005

AbstractThe inhibitory effect of topically applied flurbiprofen, a newer nonsteroidal antiinflammatory agent, on prostaglandin biosynthesis in human skin biopsies in primary irritant dermatitis was examined. The flurbiprofen‐treated areas synthesized significantly less PGE1 (279 pg/mg dry weight) than placebo‐treated inflamed skin (626 pg/mg dry weight). The average inhibition in 11 treated patients was 55% (P < 0.01 with Wilcoxon's signed rank test). Furthermore the anti‐inflammatory effect of flurbiprofen was clinically evaluated, and a poor correlation was found between the reduction of prostaglandin synthesis and the clinical effects of flurbiprofen.
Repeated acquisition of three‐response chains for food reinforcement in the rat
Authors: Pollard Gerald T. , McBennett S. Teresa , Rohrbach Kenneth W. , Howard James L. 
Published: January 2005

AbstractAdult male hooded rats responding on three contact sensors for food reinforcement were trained to acquire a different three‐response sequence each day. Twelve three‐response sequences were used; with minor exceptions, the series of 12 was run four times in two rats and twice in one rat. Elapsed time and error rate for a given sequence declined over sessions and within sessions. Some sequences generated higher error rates than others. Results were generally consistent with previous results from pigeons emitting four‐response sequences. Application to the testing of drugs for therapeutic effects on cognitive deficits associated with aging is discussed.
Inhibitors of mast cell‐mediated shock in the rat: Relationship to histamine and serotonin antagonism
Authors: Awouters Frans , Niemegeers Carlos J. E. , Janssen Paul A. J. 
Published: January 2005

AbstractThirteen compounds of heterogenous chemical structure and pharmacologic profile were studied in vivo in tests that measure antagonism of histamine and/or serotonin in the rat. These tests were the compound 48/80‐lethality test, skin reactions to histamine and serotonin, the PCA test, and tryptamine‐induced bilateral convulsions and tremors. The compounds were always administered orally with a time interval of 2 hr between dose and challenge, to allow quantitative comparisons between activities in different tests. Compounds that preferentially antagonize histamine in the skin test have the same potency rank in the histamine skin test and in the compound 48/80‐lethality test. This indicates not only that H1‐antagonism is sufficient to prevent compound 48/80‐induced lethal shock, but also that the basis of the protection is the maintenance of a sufficiently large intravascular fluid volume compatible with normal cardiovascular function. Inhibition of a serotonin‐induced increase of capillary permeability may also be sufficient to prevent lethal shock, although the ergoline derivatives were much weaker than expected. For full inhibition of PCA‐reactions, doses are required that exhibit effective antagonism of both serotonin and histamine. Antagonism of tryptamine‐induced bilateral convulsions and tremors, which is a centrally mediated effect, showed no clear relation to any of the peripheral actions that were investigated.
Heterocyclic GABA analogues as new selective inhibitors of astroglial GABA transport
Authors: Schousboe A. , Larsson O. M. , Hertz L. , Krogsgaard‐Larsen P. 
Published: January 2005

AbstractA series of heterocyclic GABA analogues were tested as inhibitors of neuronal and glial GABA transport and GABA‐receptor binding. Four compounds were shown to be selective inhibitors of glial GABA uptake, and the inhibition was in each case of the competitive type. The compounds are: β‐proline, homonipecotic acid, and the bicyclic isoxazoles THPO and THAO, the Kj values for the glial uptake of these compounds were 400, 700, 550, and 600 μM, respectively. The two latter compounds may be putative anticonvulsant drugs since they are likely to cross the blood‐brain barrier, and since they almost exclusively interfere with glial GABA uptake, which presumably would lead to increased synaptic GABA levels in vivo.
Effects of tetrahydroisoquinolines on dopa decarboxylase and pyridoxal kinase
Authors: Ebadi Manuchair , Govitrapong Piyarat 
Published: January 2005

AbstractThe mechanism of the nullification of the therapeutic effects of levodopa by pyridoxine in parkinsonian patients is not known and is still a subject of much speculation. Among other suggestions, it has been proposed that pyridoxine and levodopa may form tetrahydroisoquinoline derivatives in vivo, which may in turn inhibit dopa decarboxylase or act as a false transmitter. This possibility was tested by synthesizing six tetrahydroisoquinoline derivatives and by studying their effects on dopa decarboxylase in brain homogenates. These compounds in concentrations of 50 mM did not inhibit dopa decarboxylase or pyridoxal kinase, which synthesizes pyridoxal phosphate.
A comparison of butyrophenone and tricyclic neuroleptics with narcotics in blocking withdrawal signs in rats continuously infused with morphine
Authors: Hynes Martin D. , Lal Harbans 
Published: January 2005

AbstractNarcotic dependence was established in male rats by continuous infusion of morphine given in increasing concentrations. Termination of the morphine infusion resulted in the reliable occurrence of body shakes. Narcotic drugs, morphine, fentanyl, and methadone, blocked withdrawal body shakes in a dose‐dependent manner. The butyrophenone neuroleptics, haloperidol, benperidol, and azaperone, were also effective in reducing withdrawal body shakes at doses that do not produce side effects. Trifluoperazine and chlorpromazine, two tricyclic neuroleptics were effective in reducing withdrawal shakes only at high doses that produced side effects. The anti‐withdrawal action of morphine, haloperidol, benperidol, and azaperone but not of chlorpromazine and trifluoperazine was antagonized by naloxone.
Certain GABA mimetics reduce the affinity of anions required for benzodiazepine binding in a GABA‐reversible way
Authors: Squires Richard F. 
Published: January 2005

AbstractBinding of 3H‐flunitrazepam to specific sites on rat‐brain membranes is anion‐dependent. In the absence of added ions, binding is reduced to less than 10% of maximum, and eight anions (Tris salts) were found to increase binding in a concentration‐dependent and saturable manner with affinity constants (Kd) ranging from 0.75 mM (phosphate) to 4.5 mM (chloride). The GABA mimetic THIP (200 μM) increases these Kd values from three‐ to 10‐fold, depending on the anion. The GABA mimetics isoguvacine and piperidine‐4‐sulfonic acid (P4S) increase the Kd values for chloride ion eight‐ to 10‐fold, while amino‐propanesulfonate and imidazole acetate produce smaller (2‐ to 4‐fold) increases. These effects of THIP on anion affinities are reversed in a competitive manner by GABA and muscimol. Although there is no correlation between the ability of the anions to enhance 3H‐flunitrazepam binding and their ability to substitute for chloride ion electrophysiologically, it seems possible that the ions bind to sites similar to the chloride channels associated with GABA receptors. All benzodiazepine receptors are probably coupled indirectly to GABA receptors through anion binding sites.
“Sudden death” in laboratory rats: Animal model of depression?
Authors: Porsolt R. D. 
Published: January 2005

AbstractRats when placed into a highly stressful swimming situation will frequently die within a matter of minutes. It has been suggested that death is due to experimentally induced “hopelessness.” The present paper describes procedures with which “sudden death” can be rapidly and reliably induced in laboratory rats and reports that four psychoactive drugs (imipramine, d‐amphetamine, chlordiazepoxide, and chlorpromazine) tested failed to affect survival time. It is concluded that the procedure is not useful for the screening of potential antidepressant or other kinds of psychotropic agent.
Effect of some antidepressants and flurazepam on an invertebrate model of 5HT neurotransmission
Authors: Gardner C. R. 
Published: January 2005

Abstract5HT facilitates responses of field‐stimulated body wall of Lumbricus terrestris and induces rhythmic, spontaneous contractions. This response was also induced by the 5HT agonist 5‐methoxytryptamine, the 5HT releasers fenfluramine and p‐chloramphetamine, and the 5HT uptake blockers fluoxetine and chlorimipramine but not by catecholamines, octopamine, ACh, GABA, glutamate, histamine, adenosine, amphetamine, or amitriptyline.5HTP was effective in the presence of a monoamine oxidase inhibitor. Fluoxetine potentiated 5HT and 5‐methoxytryptamine at concentrations that had little effect alone.This response has been used as a model of 5HT transmission to study some psychotherapeutic drugs. Mepiprazole enhances 5HT transmission and may release 5HT. Trazodone also enhances 5HT transmission. Nomifensine inhibited body wall responses to field stimulation but induced no 5HT‐like activity. Viloxazine was inactive in this model. Flurazepam induced spontaneity but no increase in responses to field stimulation. This response is not similar to that of 5HT and may result from an action of flurazepam unrelated to 5HT mechanisms.
Prolonged treatment with the GABA agonist THIP increases dopamine receptor binding more than it changes dopaminergic behaviour in mice
Authors: Christensen A. V. , Hyttel J. 
Published: January 2005

AbstractTo investigate the influence of the GABA‐agonist, THIP, (4,5,6,7‐tetrahydroisoxazolo [5,4‐c] pyridin‐3‐ol) on the striatal dopaminergic system in mice after repeated administration, THIP, cis(Z)‐flupentixol, or haloperidol were given alone or in combinations for 12 days. The binding of 3H‐spiroperidol was greatly increased, and that of 3H‐cis(Z)‐flupentixol was slightly increased after treatment with THIP alone. After repeated treatment with neuroleptics, only slight increases in the binding were seen. There was no additive effect when treatments with THIP and the neuroleptics were combined.Repeated administration of THIP did not induce changes in the ability of an acute dose of either haloperidol or cis(Z)‐flupentixol to antagonize methylphenidate‐induced stereotyped gnawing. The behavioural supersensitivity induced by chronic treatment with the two neuroleptics was not changed by concomitant treatment with THIP.
The discovery of psychotropic drugs by computer‐analyzed cerebral bioelectrical potentials (CEEG)
Authors: Itil Turan M. 
Published: January 2005

AbstractThe psychotropic properties of nine compounds were discovered in healthy subjects based on the effects of computer‐analyzed cerebral bioelectrical potentials or computer‐analyzed electroencephalograms (CEEG). Quantitative pharmaco‐EEG (QPEEG) studies demonstrated that CEEG profiles of mianserin (GB‐94), GC‐46, cyclacozine, mesterolone, and estradiol valerate, resembled the CEEG profiles of tricyclic antidepressants. CEEG profiles of d‐ and I‐norgestrel and cyproterone acetate showed similarities to benzodiazepine anxiolytics, and profiles of lisuride hydrogen maleate resembled psychostimulant compounds. Thus, antidepressant, anxiolytic, and “psychostimulant” effects were predicted for these compounds. Subsequent clinical trials confirmed the antidepressant effects of mianserin, GC‐46, and mesterolone in depressed patients; the anxiolytic effects of I‐norgestrel and cyproterone acetate in anxiety syndromes; and the “psychostimulant” properties of lisuride hydrogen maleate in the “geriatric” population. However, animal pharmacology and biochemical investigations failed to predict any psychotropic properties for these compounds.
Three‐dimensional computer modeling as an aid to drug design
Authors: Humblet Christine , Marshall Garland R. 
Published: January 2005

AbstractThree‐dimensional computer graphic systems are an emerging tool in the design of therapeutic compounds. The molecular recognition process involved in drug‐receptor interaction implies a three‐dimensional stereospecificity shared by a set of drugs of similar pharmacological action. In investigating the pharmacophore, it is therefore necessary to go beyond two‐dimensional structures by including the description of the spatial properties of drugs.This review describes both current and potential tools that a graphic computer can support to help the medicinal chemist in his structure‐activity puzzle. An outline of the systems presently in use for this purpose and a summary of recent applications is given. Some current developments undertaken in our research group are presented in the field of opiates, GABA, clonidine, antipsychotics, and S‐adenosyl‐L‐methionine inhibitors.
Bradykinin receptors in isolated intestinal smooth muscle
Authors: Chase Arleen , Volicer Ladislav 
Published: January 2005

AbstractAlthough bradykinin has been long studied, its biological relevance is still unclear. The enzymes that form and degrade bradykinin appear to be numerous and ubiquitous, and its “receptors” are both species and tissue specific. Therefore, despite the fact that a multitude of compounds have been synthesized and screened as receptor antagonists, to date only one specific antagonist has been identified and it is only active in the rabbit aorta. This review is designed to present what is known about bradykinin receptors in intestinal smooth muscle. Relevant background material and a discussion of evidence for bradykinin's mechanism of action are also presented.
Reassessment of the anticonvulsant activity of diphenylacetylurea
Authors: Amato Robert J. , Jones Gary L. 
Published: January 2005

AbstractOn the basis of current information about the structure‐activity relationships of anticonvulsant compounds, it is predicted that diphenylacetylurea should possess some degree of antielectroshock activity. However, past attempts to demonstrate this have failed. In the present investigation the authors have determined that this compound does in fact possess such efficacy, although its potency is relatively low in comparison with phenytoin and phenobarbital. The difference in potency among these drugs is greatest when expressed in terms of the i.p. dosage, and much smaller when expressed in terms of blood or brain concentrations. The difference on the basis of i.p. dosage might be due to differences in bioavailability, but the lower potency of diphenylacetylurea expressed in terms of brain concentration is possibly due to its very high lipid solubility, as discussed in the text.