Depletion of synaptic vesicles at the frog (Rana pipiens) neuromuscular junctions by tetraphenylboron

Summary At the frog neuromuscular junction tetraphenylboron produced a decrease in miniature endplate potential amplitude, accompanied by a decrease in the number but not the size of synaptic vesicles.This work was supported by NIH Grants Nos NS-07740 and NS-05707 to R. L. P. and was done during the tenure of a Research Fellowship of Muscular Dystrophy Associations of America, a Wellcome Research Travel Grant and a grant from the Carnegie Trust for the Universities of Scotland to I. G. M. The assistance of Dr.R. M. Schnitzler, W. G. Boldosser andP. M. Spannbauer is gratefully acknowledged.     

Depletion of synaptic vesicles at the frog (Rana pipiens) neuromuscular junctions by tetraphenylboron.

At the frog neuromuscular junction tetraphenylboron produced a decrease in miniature endplate potential amplitude, accompanied by a decrease in the number but not the size of synaptic vesicles.     

Autoradiographic studies on the neurosecretory hypothalamo-hypophysial system of the grass frog (Rana pipiens) after disconnection of the distal hypophysis

Zusammenfassung Nach Durchschneidung der proximalen Hypophyse wird im proximalen und distalen Stumpf der Neurohypophyse ein erhöhter Gehalt an neurosekretorischen Granula festgestellt. Die Tatsache, dass nur proximal S³⁵-L-Cystein-Hydrochlorid nachgewiesen werden kann, schliesst die immer wieder vorgebrachte Hypothese einer distalen Neurosekretsynthese endgültig aus.

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Supported by NIH grant No. NB-06641 and the Space Sciences Research Center of the University of Missouri.     

Morphological and functional changes in the distal hypothalamo-neurohypophysial system of the grass frog (Rana pipiens) after transection of the proximal neurohypophysis

Zusammenfassung Nach Durchtrennung der proximalen Neurohypophyse wird im distalen Stumpf eine gegenüber Kontrolltieren erhöhte Menge paraldehyd-fuchsinpositiver Substanz gefunden, die im Elektronenmikroskop einwandfrei als Neurosekret identifiziert werden konnte. Die im Tierversuch ermittelte erhöhte, blutdrucksteigernde Aktivität des distalen Teils der Neurohypophyse spricht für eine lokale Synthese des Neurosekrets.

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Supported by NIH Grant No. NB 06641 and the Space Sciences Research Center of the University of Missouri.     

Hypophysial hormones and a G1 block in the lens epithelium of the adult frog (Rana pipiens)

Summary Mechanical injury initself may be responsible for the transition of lens epithelial cells from the G₀ to the G₁ compartment of the cell cycle. This traverse which does not depend on DNA-dependent hypophysial hormones may be in part reversible.     

Inhibitory effects of dibutyryl and cyclic AMP on the compound action potential in the frog (Rana pipiens) sciatic nerve

Résumé Le dibutyryle et l'AMP cyclique ont apparement un effet sur la conductibilité membraneuse. Cet effet se marque par une réduction d'amplitude et de vitesse de conductibilité aussi bien que par une augmentation du seuil à atteindre et du retard dans l'élaboration du processus. Ces effets ont été confirmés par la théophylline et la caféine. Les ions de calcium semblent accélérer les effets du AMP cyclique en augmentant la résistance membraneuse (réduction d'amplitude de l'impulsion nerveuse) de 30%.     

The effect of perchlorate ion and some pharmacological agents on the sensitivity of the frog (Rana pipiens) rectus abdominis to acetylcholine

Zusammenfassung Die Reaktion des mit Eserin vorbehandelten musculus rectus abdominis des Frosches auf Acetylcholin liess sich durch Oxotremorin (2.0·10^–5 M), Arecolin (2.0·10^–5M), Aceclidin (1.0·10^–4 M) und Carbachol (2.0·10^–7 M) verstärken, während Atropin (1.0·10^–5 M) hemmend wirkte. Perchlorationen in Konzentrationen über 2 · 10^–4 M sensibilisierten den Froschmuskel erheblich und reduzierten die Grenzdosis, bei der eine Potenzierung durch Substanzen mit muskarinähnlicher Wirkung beobachtet wird. Alle beschriebenen Reaktionen liessen sich durch Gehirnextrakte verstärken, in denen zuvor Acetylcholin durch Kochen in alkalischer Lösung zerstört worden war.

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This work was supported by NIH Grants No. NB 03007 and No. 5-F1-GM-22,905.     

The control of the frog (Rana esculenta) thumb pad

Summary Extirpation of the pars distalis of the pituitary or castration in any period of the year cause thumb pad regression. Thumb pad development is regulated by an interaction of both temperature and androgenic hormones.Work done under the C.N.R.-finalized project Biologia della Riproduzione.     

A human calcitonin-like molecule in the ultimobranchial body of the amphibia (Rana pipiens)

Summary As assessed by radioimmunoassay, and high performance liquid chromatography (HPLC), frog ultimobranchial calcitonin was found to be similar to synthetic human calcitonin but completely different from synthetic salmon calcitonin.Acknowledgments. This work was supported in parts by grants from the Medical Research Council, Wellcome Trust, Spanish Ministry of Universities and Egyptian Ministry of High Education.     

Effects of diphenylhydantoin on transport processes in frog skin (Rana ridibunda)

Résumé La diphénylhydantoïne agit sur la face externe de la peau de grenouille en provoquant une augmentation de la différence de potentiel et du courant de court circuit. L'effet est rapide, soutenu et réversible. Des interactions entre DPH, ocytocine, amiloride et amphotéricine B ont été étudiées.     

The response of frog taste cells (Rana nigromaculata andRana catesbeana)

Zusammenfassung Die Registrierung der Rezeptorpotentiale einzelner Geschmackszellen von Raniden (R. nigromaculata undR. catesbeana) bei Reizung mit 4 Grundgeschmacksarten mittels Glasmikroelektrode ergibt: Ruhepotential der Rezeptorzellen 10–35 mV (innen negativ). Die einzelnen Geschmackszellen antworten auf mehr als 2 Geschmacksarten und zeigen im Hinblick auf ihre Antwortmuster zellcharakteristisches Verhalten.     

The nucleolar chromosome in embryos of Rana pipiens

Summary Karyotype analyses of prometaphases from medullary plate cells derived from mid-neurulae of Rana pipiens have led to the identification of the nucleolar chromosome and nucleolar organizing region, which is located on the longer arm of a small sub-metacentric chromosome (No. 10).Supported in part by research grant GB19631X from the Natioal Science Foundation. This study constituted a portion of a dissertation submitted by G. R. N. to the Medical College of Pennsylvania in partial fulfillment of requirements for a Ph. D. degree.Supported by NDEA and subsequently NSF predoctoral traineeships.To whom reprint requests should be sent.     

Existence of a non-retinotopic contralateral retino-tectal visual projection in the normal frog Rana esculenta L]

In the Frog, after unilateral optic nerve and tract section, contralateral visual responses were recorded in the tectum ipsilateral to the section. These responses were elicited by stimulation of a unique spatial region located near the projection of the contralateral eye optic axis and could be randomly recorded on the tectal surface. The possible pathways and the role of such retino-tectal afferences are discussed.     

Latency of taste nerve signals in frog (Rana catesbeiana).

The latency of frog gustatory neural impulses to 1.0 M NaCl was a mean of 86 msec. Electrical stimulation of taste cell membranes produced gustatory neural impulses with the mean 5 msec latency. It is concluded that most of the 86 msec latency of taste nerve responses to 1.0 N NaCl is due to the latency of taste receptor potential following the onset of gustatory stimulation.     

Topography of the tecto-tectal component of the main ipsilateral visual pathway of the frog (Rana esculenta L.)]

The detailed topography of the tecto-tectal component of the Frog's ipsilateral visual pathway is electrophysiologically obtained by mapping the optic lobes. This linkage transfers the visual information explored along a transversal tectal row on to an homologous line oriented at 130 degrees on the opposite tectum. The ipsilateral projection of the temporo-nasal axis of the retina, but not of the antero-posterior axis of the visual field, is reversed compared to its contralateral projection. Finally, the majority of the homologous tectal points are asymmetrical with respect to the animal's sagittal axis.     

Primary visual centers in the frog (Rana esculenta L.) and the problem of ipsilateral projections. Radioautographic study]

The topographic organization of the frog's primary visual system has been reexamined in Rana esculenta using autoradiographic technique. 10 to 24 hrs following an intraocular injection of tritiated proline, an intense labelling was observed contralaterally in the various retinal projection centres (preoptic area); neuropils of Bellonci; corpus geniculatum of the thalamus; posterior thalamus; posterodorsal preoptic area; magnocellular pretectal nucleus and basal optic nucleus; tectal laminae A to G of Potter), as already described. Furthermore, the presence of a ipsilateral projection within the hypothalamus (preoptic area), the thalamus (neuropils of Bellonci and corpus geniculatum) and the pretectium (posterior thalami neuropil, pretectal optic area) is confirmed. On the other hand, the existence of ipsilateral retinotectal (to Potter's lamina F) and retino-tegmentomescencephalic projections (to the basal optic nucleus), which were thusfar questioned, has been demonstrated.