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Biomedical subjects

J L Fuller

Publications and source records attributed to J L Fuller.

At least 55 records · Page 3Linked to original sources
PubMed1976

Issues in the genetics of social behavior.

The genetics of social behavior presents special difficulties because the phenotype is the product of an interaction between two or more individuals. Social interactions are of two kinds: (1) cooperative, in which the probabilities of transmission of the genes of all participants are similarly affected by the outcome, and (2) agonistic, in which the probabilities for the participants are affected in opposite directions. The latter are of particular interest for evolutionary theory. Three major types of designs for measuring social behavior in genetic experiments are available: (1) homogeneous sets, (2) standard tester, and (3) tester panel representing a reference population. The advantages and limitations of each method are discussed. Important areas for future development include the relationship of genetic and experiential factors in early life to social status as an adult and the extension of the genetic analysis of social behavior to natural populations.

Animals↗
PubMed1976

Effect of aminooxyacetic acid on audiogenic seizure priming in C57BL/6J and SJL/J mice.

An attempt was made to determine the effects of genetic and temporal factors on the inhibitory action of aminooxyacetic acid on priming for audiogenic seizures. SJL/J and C57BL/6J mice were administered 20 mug/g of AOAA subcutaneously, employing either a 2 hr or 5 hr injection-prime interval, and either a 2 day or a 9 day prime-test interval. It was found that an inhibitory effect on priming occurred only in C57BL/6J mice; this effect was significant only for the 9 day groups, and was observed when wild running was used as the criterion for seizures, but not when clonic convulsion was the criterion. Effects of AOAA are discussed in relation to theories of seizure development through disuse supersensitivity, or by chemical actions on the GABA system.

Acetates↗
PubMed1976

Selection for spontaneous or priming-induced audiogenic seizure susceptibility in mice.

Four lines of mice were selectively bred from a heterogeneous foundation stock for audiogenic seizure prone (SP), priming prone (PP), moderately priming prone (MPP), and seizure resistant (SR). Significant changes in proportions of animals showing the desired phenotypes were found after two generations of selection, indicating involvement of genetic components in these behavioral characteristics. Although response to selection for spontaneous seizure proneness was rapid, the results do not support a view that initial seizure risk is controlled by a single recessive gene. The effects of tympanic membrane perforation on development of seizure susceptibility in these four selected lines were investigated in Experiment 2. Results indicate that the method is highly effective in inducing seizure susceptibility in the PP mice and the SR mice, but not so effective for the SP and the MPP lines. These results suggest that spontaneous and priming-induced seizure susceptibility could be due to development of hyperreactivity in centripetal auditory structures brought about by reduction of auditory input. They also suggest that the phenotypic difference between the PP and the SR lines could be due to differences in their cochlear susceptibility to stimulation damage but that a qualitatively different mechanism is involved in the MPP line.

Acoustic Stimulation↗
PubMed1975

Regulation of ornithine decarboxylase in 3T3 cells by putrescine and spermidine: indirect evidence for translational control.

Addition of putrescine of spermidine prevents the increase in ornithine decarboxylase activity in cultures of 3T3 cells brought about by pituitary growth factors and results in a rapid, specific, and reversible reduction of enzyme activity in cultures previously stimulated by the growth factors. These effects are not due to polyamine toxicity and do not require other organic medium components. The amines apparently share a single carrier-mediated transport system in 3T3 cells. Methylglyoxal bis(guanylhydrazone), an inhibitor of spermidine synthesis from putrescine was found to also inhibit uptake of each amine. Studies with this drug indicate that each amine is effective without further metabolism. Since ornithine decarboxylase activity decays more rapidly in the presence of each polyamine after addition of camptothecin, the major locus of amine action appears to be in the cytoplasm. However, direct inhibition of the enzyme in vivo by assimilated amines appears to account for at most a small part of the reduction in activity, a conclusion supported by the inability to recover activity in vitro. Also, neither amine seems to act by accelerating enzyme inactivation. When amines are removed from the medium, the subsequent recovery of enzyme activity is totally prevented by trichodermin, an inhibitor of protein synthesis, but is only slightly reduced by camptothecin. It is suggested that both putrescine and spermidine reduce ornithine decarboxylase activity by selectively inhibiting translation.

Camptothecin↗
PubMed1975

Neonatal thyroxine administration, behavioral maturation, and brain growth in mice of different brain weight.

L-thyroxine in amounts of .5, 1, and 2 mug was injected daily from age 5 through 14 days in 3 lines of mice selected for high (H), medium (M), or low (L) brain weight. Controls (injected with vehicle only) of these lines differed in ages of eye-opening, first auditory startle, and perfection of a surface-righting response. Thyroxine at .5 mug/day accelerated the maturation of eye-opening, auditory startle, and aerial-righting response, but had no effect on a grasping response or open-field activity. Brain weights were depressed significantly in all thyroxine treated groups except in the 9k-mug dosage in H mice.

Age Factors↗
PubMed1975

Septal lesions and behavior: effects of presurgical rearing and strain of mouse.

Male mice (C57BL/10J or SJL/J strains) were reared in either enriched social cages or restricted individual cages from 25 days of age until they underwent septal or control surgery 1 mo later. Enrichment differentially altered septal or control behavior as measured by: fluid consumption of water, saccharin, and quinine; performance on a rotorod; and the acquisition of an active avoidance task. The interactions of presurgical history with brain damage were manifested differently in the two strains of mice. The importance of attending more to genetic and presurgical history in attempts to define the effects of brain damage on behavior and to determine the function of brain structures is discussed.

Animals↗
PubMed1975

Practical considerations of a flexible course in a nonflexible curriculum.

In the context in which this course was conducted, i.e., flexibility within an otherwise rigid curriculum, and no deadlines, several conclusions can be drawn: 1. Students used considerably more time than when the course was traditionally structured. 2. Quality of performance in the preclinical laboratory was significantly better. 3. Students took longer to complete the laboratory requirements than didactic requirements. 4. Some reasonable deadlines are necessary. 5. Student and instructor attitudes favored flexibility.

Anatomy↗