Responses of single neurons in the olfactory bulbs of rabbits,dogs, and cats to X-rays

Zusammenfassung Die durch Röntgenstrahlen (1 R/sec) erzeugten elektrischen Impulse einzelner Nervenzellen der Geruchszwiebel wurden in narkotisierten Katzen, Kaninchen und Hunden gemessen. Als typische Reaktion wurde eine kurzfristige Erhöhung der elektrischen Impulse gefunden. Somit sind die von Röntgenstrahlen ausgelösten elektrischen Impulse des Geruchsystems kein artspezifisches, sondern vielmehr ein allgemeines Phänomen.

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This study was supported through funds provided by the Bureau of Medicine and Surgery, U.S. Navy, and the Defense Atomic Support Agency. The opinions and assertions contained herein are those of the authors and are not to be construed as the official views of the Navy Department.     

Two types of muscarinic acetylcholine receptors in Drosophila and other arthropods

Muscarinic acetylcholine receptors (mAChRs) play a central role in the mammalian nervous system. These receptors are G protein-coupled receptors (GPCRs), which are activated by the agonists acetylcholine and muscarine, and blocked by a variety of antagonists. Mammals have five mAChRs (m1–m5). In this study, we cloned two structurally related GPCRs from the fruit fly Drosophila melanogaster, which, after expression in Chinese hamster ovary cells, proved to be muscarinic acetylcholine receptors. One mAChR (the A-type; encoded by gene CG4356) is activated by acetylcholine (EC₅₀, 5 × 10^?8 M) and muscarine (EC₅₀, 6 × 10^?8 M) and blocked by the classical mAChR antagonists atropine, scopolamine, and 3-quinuclidinyl-benzilate (QNB), while the other (the B-type; encoded by gene CG7918) is also activated by acetylcholine, but has a 1,000-fold lower sensitivity to muscarine, and is not blocked by the antagonists. A- and B-type mAChRs were also cloned and functionally characterized from the red flour beetle Tribolium castaneum. Recently, Haga et al. (Nature 2012, 482: 547–551) published the crystal structure of the human m2 mAChR, revealing 14 amino acid residues forming the binding pocket for QNB. These residues are identical between the human m2 and the D. melanogaster and T. castaneum A-type mAChRs, while many of them are different between the human m2 and the B-type receptors. Using bioinformatics, one orthologue of the A-type and one of the B-type mAChRs could also be found in all other arthropods with a sequenced genome. Protostomes, such as arthropods, and deuterostomes, such as mammals and other vertebrates, belong to two evolutionarily distinct lineages of animal evolution that split about 700 million years ago. We found that animals that originated before this split, such as cnidarians (Hydra), had two A-type mAChRs. From these data we propose a model for the evolution of mAChRs.     

Intracellular distribution of estrogen receptors: A function of preparation

Summary The intracellular distribution of unbound estrogen receptor was estimated using nonaqueous and aqueous isolation of nuclei and autoradiography. The estimated amount of nuclear receptor varied greatly with the procedure used and thus caution is urged in approximating the in vivo intracellular distribution of receptors.This study was supported in part by US PHS Career Development Award No. NS000164 and PHS Grant No. NS21933.     

Change of threshold during dark adaptation measured with orange and blue light in cats and rabbits

Zusammenfassung Bei Kaninchen und Katzen wird während Dunkeladaptation die für schwellennahe Antworten konstantei Amplitude im Elektroretinogramm notwendige Lichtenergie bestimmt. Nach Helladaptation (15 min, Reizschwelle am Ende der Helladaptation 10^–5 bis 10^–6 der Dunkelkontrolle) zeigt sich in der Dunkeladaptationskurve ein Knick ähnlich dem, der beim Menschen den Übergang der Zapfen-zur Stäbchenadaptation anzeigt. Beim Kaninchen sind die für 462 und 605 mµ gemessenen Reizschwellen vor und nach dem Knick mit den im dunkeladaptierten Zustand erhaltenen Werten identisch. Unter gleichen Bedingungen wird bei der Katze bis zum Knick eine Purkyn-Verschiebung gesehen, jedoch fehlt diese nach Helladaptation an ein schwächeres Licht, während der Knick nachweisbar bleibt.     

An excitatory component of the jaw opening reflex in the temporal and masseter muscles of cats and monkeys

Résumé Après stimulation électrique de la gencive chez le singe et du nerf lingual chez le chat, une réponse réflexe de courte latence à été enregistrée au niveau du muscle temporal et du masseter. La latence de cette réponse est plus rapide que celle de la réponse digastrique induite par le même stimulus. La réponse temporale de courte latence peut également être observée en l'absence tant d'une réponse digastrique que du réflexe d'ouverture de la gueule.

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This investigation was supported by U.S. Public Health Service Grant No. NS 08604.L. J. Goldberg holds U.S. Public Health Service Career Development Award No. 5 K04 DE11616. The technical assistance of MissSheryl K. Simms is greatly appreciated.     

On theβ-adrenergic receptors in salivary glands of rat and dogs

Zusammenfassung Nachweis an Ratten und Hunden, dass Salbutamol, ähnlich wie Noradrenalin, nur in höherer Dosierung, die Speichelsekretion der Submaxillaris, nicht aber die der Parotis erhöhen kann. Diese Wirkung kann durch Propanolol aufgehoben werden, was zeigt, dass sich in der Submaxillaris offenbar ₁-Rezeptoren befinden.     

Release of endogenous pyrogen in cats by staphylococcal enterotoxin B

Résumé On a montré la présence d'une substance pyrogène qui avait les caractéristiques physiologiques endogènes dans le plasma et dans le sérum sanguin de félin, pris 5 h après l'injection i.v. d'entérotoxine staphylococcique B.

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Supported by USPHS Gratn No. AI-05963. A preliminary report is abstracted in Fedn. Proc.25, 433 (1966).     

Digoxin distribution between plasma and myocardium in hypoxic and non-hypoxic dogs

Summary The relationship between plasma and myocardial digoxin concentrations was investigated in hypoxic and nonhypoxic dogs. The results indicate that hypoxic dogs have lower plasma levels, higher myocardial levels, and an altered myocardial distribution when compared to non-hypoxic dogs.     

Comparative distribution on niobium-95 in maternal and fetal rats and rabbits

Summary Pregnant rats and rabbits were injected with Nb95 towards the end of gestation. In rats, all maternal tissues showed higher concentrations compared to the fetal organs; the highest ratio was 0.6 in bone. In rabbits a different distribution was found. The fetal bone exhibited a 3.5 times higher concentration of Nb95 than the maternal one.The work was supported by a grant of the Bundesministerium des Innern F.R.G.     

Comparative distribution on niobium-95 in maternal and fetal rats and rabbits

Pregnant rats and rabbits were injected with Nb95 towards the end of gestation. In rats, all maternal tissues showed higher concentrations compared to the fetal organs; the highest ratio was 0.6 in bone. In rabbits a different distribution was found. The fetal bone exhibited a 3.5 times higher concentration of Nb95 than the maternal one.