Genetic and environmental influences on reactive and spontaneous locomotor activities in rats

Paired groups of rats (derived from divergent, selective breeding or living in divergent environmental conditions) were compared with regard to locomotor activities. Intrapair differences were found to vary non-systematically, depending upon whether the rats were initially exposed to a test-environment with or without a slight environmental modification (reactive activities), or were allowed to habituate extensively to the environment (spontaneous activity). Since the behavioral patterns were found to represent distinct entities, this pointed to the necessity of differentiating clearly between spontaneous and reactive activities and indicated, once again, that both genetic and environmental influences are important in these behaviors and must be taken into account. Accepting and controlling for these variables makes it possible to use the factor of individual differences in laboratory animal behavior to advantage.     

Genetic and environmental influences on reactive and spontaneous locomotor activities in rats

Paired groups of rats (derived from divergent, selective breeding or living in divergent environmental conditions) were compared with regard to locomotor activities. Intrapair differences were found to vary non-systematically, depending upon whether the rats were initially exposed to a test-environment with or without a slight environmental modification (reactive activities), or were allowed to habituate extensively to the environment (spontaneous activity). Since the behavioral patterns were found to represent distinct entities, this pointed to the necessity of differentiating clearly between spontaneous and reactive activities and indicated, once again, that both genetic and environmental influences are important in these behaviors and must be taken into account. Accepting and controlling for these variables makes it possible to use the factor of individual differences in laboratory animal behavior to advantage.     

The protective effect of estrogens against spontaneous pancratic islet and renal changes in aging male rats

Zusammenfassung Langzeitbehandlung mit Oestrogen bei von früher Jugend an daran gewöhnten männlichen Ratten ergibt einen vollständigen Schutz gegen Spontanfibrosis der Langerhansschen Inseln und ist ebenso wirksam gegen senile Nierenveränderungen.     

Reversible depression of spontaneous brain electrical activity induced by actinomycin D and 7-aminoactinomycin D in rats

Summary Various types of actinomycin (C, D, S₂, I and V) and 7-amino-analogue of actinomycin D were injected into the right lateral ventricle of the brain through a chronically implanted cannula. In rats but not in mice actinomycin D, actinomycin S₂ and 7-aminoactinomycin D caused depression of EEG, while cardiac and respiratory activity were maintained. This effect of the EEG was reversible and a normal EEG pattern reappeared at least 3 h after administration.     

High glucose-induced enzyme activity changes in cultured cell lines established from the kidneys of Chinese hamsters with aglycosuria or spontaneous glycosuria

Summary Chinese hamster kidney epithelial-like cells derived from highly inbred nondiabetic (AV) and diabetic (XA) genetic sublines were passaged in medium containing 100 or 400 mg/dl glucose. The effect of high medium glucose on the activities of 5 enzymes involved in glucose metabolism was followed and significant glucose-dependent difference was observed. The effects, however, were opposite in cells derived fromAV andXA sublines.     

The finding of viral particles in spontaneous mammary adenocarcinoma in rats

Riassunto Per la prima volta viene segnalato il reperto di particelle virali in adenocarcinoma mammario spontaneo del ratto.     

Phosphoinositide content in the erythrocyte membrane of rats with spontaneous and renal hypertension

Summary The increase of the content of triphosphoinositide in the erythrocyte membrane in rats with spontaneous and renal hypertension and decrease of phosphatidylinositol at spontaneous hypertension were revealed.     

The effect of estrogen and castration on a spontaneous pancreatic islet change in rats

Zusammenfassung Die bei alternden männlichen Sprague-Dawley-Ratten auftretende spontane Fibrose und Vergrösserung der Langerhansschen Inseln kann durch eine im Alter von 20 Wochen eingeleitete östrogenbehandlung verhindert werden. Diese Schutzwirkung der östrogene kann Ausdruck eines direkten Einflusses auf die Inseln oder eines indirekten Einflusses durch den peripheren Kohlehydratstoffwechsel sein. Eine Kastration vermochte diese Veränderungen an den Inseln nur wenig zu verhindern.     

Gamma aminobutyric acid induced changes in the spontaneous firing rates of insect neurons

Zusammenfassung -Aminobuttersäure (GABA) vermindert die Impulsfrequenz der spontan-aktiven Nervenzellen beim Insekt. Wirksame Konzentrationen betragen 0,1–25 · 10^–4 M. Ein unerwartetes Ergebnis war die Beobachtung, dass nach Applikation von GABA eine Erhöhung der Impulsfrequenz vor der Verminderung stattfindet.

---

---

This investigation was supported in part by the NSF College Teacher Research Participation Program, Grant No. GY-682, and by NSF Undergraduate Research Participation Program, Grant No. GY-151. — We thank Mr.A. McAfee, our undergraduate participant, for his assistance in this investigation.