Effects of deneravation and decentralization upon taste buds.

Denervation of vallate papillae results in failure of tactile and gustatory reception at a time when impulse conduction in the distal stump of the glossopharyngeal nerve is still unimpaired; delay of receptor deficit depends on axon length between receptor and axotomy sites; taste buds disappear by 10 days. Decentralization, through intracranial rhizotomy, does not modify lingual receptors structure or function.     

A transitional cell type in taste buds

Riassunto Nella presente nota è brevemente analizzato l'aspetto ultrastrutturale di una cellula talora osservabile nel calice gustativo e caratterizzata da una notevole abbondanza di reticolo endoplasmatico liscio.

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Acknowledgment. The technical help ofV. Panetta was greatly appreciated.     

Some ultrastructural observations on the denervated skeletal muscle of frog.

The frog skeletal muscle resists atrophy for a long time after denervation. If, however, the entry of the nerve is prevented for more than 3.5 months, small muscle portions, sometimes containing nucleus, are sequestered from the parent muscle fibre. The basal lamina does not dissociate from these detached muscle portions.     

Some ultrastructural observations on the denervated skeletal muscle of frog

Summary The frog skeletal muscle resists atrophy for a long time after denervation. If, however, the entry of the nerve is prevented for more than 3.5 months, small muscle portions, sometimes containing nucleus, are sequestered from the parent muscle fibre. The basal lamina does not dissociate from these detached muscle portions.     

Some ultrastructural observations of cotyledonary tissue and microbodies fromPisum sativum

Zusammenfassung Mikrokörperchen mit Einfachmenbranen wurden bei 4 Tage alten Kotyledonen vonPisum sativum studiert und für einen cytochemischen Katalase-Test elektronenmikroskopisch verwendet. Das granuläre Reaktionsprodukt aus dem 3,3-diamino-benzidin Test für Katalase wurde ausschliesslich in den Einfachmembranen der Mikrokörperchen gefunden.     

Preliminary ultrastructural observations on the venom glands of Asilides (Diptera-Brachycera)]

The venom gland epithelium of the Asilidae is apparently made up of two types of cells which are differentiated by the structure of some components. The two types of cells exhibit an extensive protein synthesis and the secretory process seems to be apocrine. The significance of these two types of cell is discussed.     

Immunological observations following vasectomy.

Lymphocytotoxic antibodies (LCA) against panels of normal lymphocytes and leukemic B-cells were demonstrated in vasectomized men. Since vasectomy is known to induce antibody formation to spermatozoa, the demonstration of these lymphocytotoxic antibodies may be related to antigenic constituents of spermatozoa such as HLA or B-cell alloantigens. Long term follow-up is needed to clarify the clinical significance of these antibodies.     

Receptor potential of rat taste cell to potassium benzoate.

Rat taste cells responded to relatively low concentrations of K-benzoate with a hyperpolarization and to the high concentrations with a depolarization. During both responses the membrane resistance of a taste cell decreased. Depolarization elicited by application of a combination of 0.25 M NaCl and 0.05 M K-benzoate was smaller than that by the NaCl alone, indicating a depressant action of K-benzoate.     

Severe conditioned taste aversion elicited by venom of Russell's viper.

Conditioned taste aversion (CTA) established in rats by associating saccharin drinking with subsequent poisoning by Russell's viper venom. Retention test revealed 76 and 56% reduction of saccharin intake in venom and antivenom-venom groups. No CTA was observed in antivenom and control groups.     

Formation of buds in leaves ofAtropa belladonna L. in the in vitro culture

Zusammenfassung Blattmaterial vonAtropa belladonna vermag unter geeigneten Bedingungen ganze Pflanzen zu regenerieren. Ausgangspunkt der Knospenbildung ist das Pallisadenparenchym.

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Acknowledgements: I wish to thank the head of the Department of General Botany Prof.A. Szweykowska for the facilities and critical reading of this report.     

Some observations on the Rohon-Beard cell perikaryon.

During the hatching period, the Rohon-Beard cells of Salmo gairdneri showed definite structural maturity of their perikarya, which is in contrast to the amphibian species investigated, where neuronal maturation of the Rohon-Beard cells is finished only in later -- posthatching -- developmental stages.     

An initial phasic depolarization exists in the receptor potential of taste cells.

When frog taste cells were stimulated by varying salts after adaptation to water, quinine or acetic acid, a phasic depolarization appeared initially in the receptor potential of taste cells. The initial transient depolarization may be related to the enhancement of an initial phasic response in the taste nerve.