Number of dopamine neurons predicts prolactin levels in two inbred mouse strains

Summary Mice of the BALB/cJ strain have more dopamine neurons than mice of the CBA/J strain. We now report that BALB/cJ mice have less circulating and pituitary prolactin than CBA/J mice, a relationship expected from the difference in tuberoinfundibular dopamine neuron number.     

Changes in brain dopamine levels and aggressive behavior with aging in 2 mouse strains

Summary The genetic programming of brain monoamine changes with aging show remarkable differences in 2 mouse strains. A marked increase in dopamine occurred in 32-week-old grouped ICR mice and the males showed intense irritability and aggressive behavior. Brain amines changed only slightly in old C57BL6J mice and behavior remained benign. Old females showed similar amine changes but aggressive behavior did not occur in either strain.     

Changes in brain dopamine levels and aggressive behavior with aging in 2 mouse strains

The genetic programming of brain monoamine changes with aging show remarkable differences in 2 mouse strains. A marked increase in dopamine occurred in 32-week-old grouped ICR mice and the males showed intense irritability and aggressive behavior. Brain amines changed only slightly in old C57BL6J mice and behavior remained benign. Old females showed similar amine changes but aggresive behavior did not occur in either strain.     

Arylsulfatase B synthesis and clearance in inbred mouse strains

Arylsulfatase B activity levels were approximately 2-3-fold higher in adult C57BL/6J liver and kidney compared to corresponding tissues from A/J inbred mice. In vivo incorporation of tritiated leucine into C57BL/6J hepatic arylsulfatase B reached a maximum approximately 15 h after injection. The label was cleared from C57BL/6J arylsulfatase B with an apparent half-life of 36 h. The relative rates of synthesis of C57BL/6J and A/J arylsulfatase B were similar; however, the A/J enzyme was cleared more rapidly from liver tissue. C57BL/6J kidney arylsulfatase B appeared to be synthesized at a 2-3-fold higher rate than the corresponding A/J enzyme. These trends suggest genetic regulation of arylsulfatase B is effected through different means in liver and kidney from adult mice of these two inbred strains.     

Spontaneous maze ambulation in two mouse strains

Summary A simple device is described, which permits us to quantify several parameters of spontaneous behaviour of small animals. Using this device with mice we obtained statistically satisfactory results, showing a strong genetic influence on the behavioural characteristics tested.We wish to thank Mr R. Laplace for technical help, Mr J. P. Arnould for electronic work as well as I.N.S.E.R.M.-SCR 3.     

Effects of d-amphetamine upon open field behaviour in two inbred strains of mice

Résumé Chez des souris C57BL/10J, on constate une augmentation de l'activité locomotrice durant tous les 7 jours qui suivent leur injection avec la d-amphétamine. Chez des souris BALB/cJ, cette augmentation n'apparaît pas, sauf légèrement après le quatrième jour. Des facteurs génétiques jouent un rôle important dans la détermination de la réponse comportementale à la d-amphétamine.

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This research was funded by National Institutes of Mental Health grant No. MH-18517-01. Facilities were provided by the Maryland Psychiatric Research Center, Baltimore, Maryland.     

Separation of two strains of rats with inbred dissimilar sensitivity to doca-salt hypertension

Résumé La réponse au régime Doca-sel (D. S.) a été utilisée comme critère de sélection pour séparer, par croisement consanguin, deux colonies de rats manifestant une susceptibilité bien différente à l'hypertension artérielle. Les résultats obtenus dans la 6ème génération de nos colonies normotensive et hypertensive font l'objet de ce raport. Le rôle des facteurs héréditaires dans la susceptibilité ou la résistance à l'hypertension du type D. S. est démontrée.     

Differences in teratogenic response and in capacity to repair in embryos of two inbred strains of mice

Zusammenfassung Die Wirkung des Farbstoffes Trypanblau auf die embryonale Entwicklung von 2 Mäusestämmen, des C57B1/6 Stammes und des Swiss-Albino-Stammes, wurde untersucht und die Ergebnisse wurden miteinander verglichen. Embryonen der beiden Stämme reagierten in verschiedener Weise auf Trypanblau. Die Injektion des Farbstoffes führte zum vollständigen Entwicklungsstillstand aller C57B1/6-Embryonen, während bei Swiss-Albino-Embryonen hauptsächlich Kopf-, Gehirn-und Schwanzabnormitäten auftraten. Bei Swiss-Embryonen nahm die Schwere der Abnormität mit fortschreitendem Alter der Embryos beträchtlich ab, obwohl die Anzahl pro Wurf unverändert blieb. Keine Veränderung in der Zahl der Abnormitäten wurde in älteren C57B1/6-Embryonen beobachtet. Die verschiedenartige Reaktion der beiden Stämme auf Trypanblau ist vielleicht darauf zurückzuführen, dass genetisch bedingte Unterschiede in der Fähigkeit, zerstörtes Gewebe während der embryonalen Entwicklung zu reparieren, vorhanden sind.

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Submitted in partial fulfillment of the requirements for the degree of Master of Arts in the Graduate Division of the College of Liberal Arts and Science of the City College of the City University of New York.     

Substrate induced alterations in tryptophan pyrrolase activity in two mouse strains

Summary Total hepatic L-tryptophan 2,3-dioxygenase activity was studied in 2 mouse strains receiving i.p. injections of L-tryptophan. After a single injection, enzyme activity was increased in albino but not pigmented mice. After 3 injections, enzyme activity was reduced in both strains. This work was partially supported by grant No. 3726-22 from the Office of Research and Sponsored Programs, Wichita State University.     

Genotype dependence of monoamine oxidase in inbred strains of mice

Summary MAO activity was found to be influenced by the genotype or strain of mouse up to 20 days of age. The strain differences observed may derive from different rates of brain development. A number of neurological mutations comprizing three pathological classes had no effect on MAO.This work was supported in part by NIH grant No. NS06448 from the National Institute of Neurological Disease and Stroke.     

Plasma prolactin levels in fetal sheep

Zusammenfassung Entwicklung und Spezifität eines radioimmunologischen Verfahrens für Schaf-Prolaktin. Zirkulierende Prolaktinmengen wurden in Fetussen bestimmt und vom 110. bis zum 122. Tage bedeutende Prolaktinmengen festgestellt.

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Supported by a grant No. HD-00394 from the National Institutes of Health.     

Pathological changes in inbred strains of mice following early thymectomy and irradiation

Summary Mice subjected to thymectomy and irradiation were found to develop a range of pathological change in various organs. These changes were accompanied by antibodies to a variety of self-components. The pattern of pathological and autoimmune change was found to vary with the strain. This strain-related expression did not appear to be associated with the major histocompatibility complex (H-2).This study was partly supported by the National Health and Medical Research Council of Australia.Author for correspondence and reprint requests.     

Regional brain [Met]-enkephalin in alcohol-preferring and non-alcohol-preferring inbred strains of mice

Scrutiny of the data from these studies reveals that the C58/J alcohol-preferring mice have significantly lower baseline methionine-enkephalin levels in both the corpus striatum and hypothalamus compared to C3H/CHRGL/2 non-alcohol-preferring mice. In other brain regions in these two strains, specifically, pituitary, amygdala, midbrain, and hippocampus, analysis of methionine-enkephalin levels did not show any significant differences. This suggests that the hypothalamus may indeed be a specific locus involved in the regulation of alcohol intake, via the molecular interaction between neuroamines, opioid peptides, as they are influenced by genetics and environment.     

Regional brain [Met]-enkephalin in alcohol-preferring and non-alcohol-preferring inbred strains of mice

Summary Scrutiny of the data from these studies reveals that the C58/J alcohol-preferring mice have significantly lower baseline methionine-enkephalin levels in both the corpus striatum and hypothalamus compared to C3H/CHRGL/2 non-alcohol-preferring mice. In other brain regions in these two strains, specifically, pituitary, amygdala, midbrain, and hippocampus, analysis of methionine-enkephalin levels did not show any significant differences. This suggests that the hypothalamus may indeed be a specific locus involved in the regulation of alcohol intake, via the molecular interaction between neuroamines, opioid peptides, as they are influenced by genetics and environment.