Changes in olfactory perception during the menstrual cycle

Summary The aim of the study was to find correlations between changes in olfactory sensitivity and the menstrual cycle. 14 young, healthy volunteers participated in the experiments. Subjects menstruated regularly and did not use oral contraceptives. Three odorants were investigated: phenylethyl alcohol, androstenone, and nicotine. Dilution series of the odorants were prepared, and presented to the subjects in order to determine the detection thresholds (triple forced choice). Additionally, the subjects' hedonic estimates of the odorants were measured, and mood states as well as hormonal levels of LH and estrogen were determined. Before the actual experiments started, subjects participated in three training sessions.One experiment was subdivided into 5 phases (two pre- and two postovulatory phases; one ovulatory phase). Only with regard to androstenone did trend analyses reveal a significant quadratic relationship between hedonic estimates and phases of the menstrual cycle, peaking at ovulation. Olfactory sensitivity was not significantly influenced by the menstrual cycle.     

External nares and olfactory perception

Lower vertebrates have more widely separated external nares than higher forms and are thus better adapted to utilize olfactory tropotaxis, or stereolfaction, than higher vertebrates which, on account of their flexible necks, must utilize klinotaxis. Snakes and tubenosed bats break the rule on account of their specialized life styles.     

External nares and olfactory perception

Summary Lower vertebrates have more widely separated external nares than higher forms and are thus better adapted to utilize olfactory tropotaxis, or stereolfaction, than higher vertebrates which, on account of their flexible necks, must utilize klinotaxis. Snakes and tubenosed bats break the rule on account of their specialized life styles.     

Changes in serum proteins due to lesion or resection of the olfactory bulbs of the rat

Resumen La sección y extirpación bilateral de los bulbos olfactorios, en ratas de ambos sexos, producen disminución de las proteínas séricas totales, albumina y globulinas y, sin modificaciones de la globulina. Esa disminución se hace significativa 21 días después de las operaciones.     

Train length perception during self-stimulation behaviour

Résumé Pendant le comportement d'autostimulation électrique intracérébrale, l'animal n'appuie sur la pédale qu'à la fin du train de stimulation. Un tel comportement est interprété en émettant l'hypothèse que l'animal perçoit la durée de la stimulation. Mais un tel comportement dépend d'une part de l'intensité de l'effet de récompense et d'autre part de l'environnement. En effet si l'intensité de la récompense est moins importante ou si des stimulations sonores inattendues surviennent, les Rats ne parviennent plus à réaliser ce comportement.

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The author is greatly indebted to Prof.M. Meulders for helpful discussion and valuable cirticisms.     

Effects of the psychodysleptic drug psilocybin on visual perception. Changes in brightness preference

Zusammenfassung Die in gesunden, jungen Volontären durch Psilocybin hervorgerufene, reversible Veränderung der bevorzugten Helligkeit kann mit der Stabilität der Wahrnehmungspersönlichkeitsstruktur, nicht aber mit der mydriatischen Wirkung der Droge in Beziehung gebracht werden.     

Differential olfactory perception of enantiomeric compounds by blind subterranean mole rats (Spalax ehrenbergi).

The behavior of mole rats (Spalax ehrenbergi) near pairs of enantiomeric compounds was examined in 901 two-choice experimental tests. Positioning of the nest and food store and the preferred location of the tested animal were used to assess attraction or aversion to the tested odorants. The results indicated that mole rats respond differentially to odors of stereoisomers (enantiomers of carvone, citronellol, and fechone). They responded to one enantiomer of each tested pair but were indifferent to or did not smell the other. Both sexes were attracted to the odor of R-(-)-carvone and repelled by the odor of (+)-citronellol. Females were attracted to the odor of (-)-fenchone while males had no preference. By contrast, all animals were indifferent to or did not smell the odor of S-(+)-carvone, (-)-citronellol, and (+)-fenchone. Further research to distinguish between these alternatives (indifference vs hyposmia/anosmia) is suggested.     

Differential olfactory perception of enantiomeric compounds by blind subterranean mole rats (Spalax ehrenbergi)

The behavior of mole rats (Spalax ehrenbergi) near pairs of enantiomeric compounds was examined in 901 two-choice experimental tests. Positioning of the nest and food store and the preferred location of the tested animal were used to assess attraction or aversion to the tested odorants. The results indicated that mole rats respond differentially to odors of stereoisomers (enantiomers of carvone, citronellol, and fechone). They responded to one enantiomer of each tested pair but were indifferent to or did not smell the other. Both sexes were attracted to the odor of R-(–)-carvone and repelled by the odor of (+)-citronellol. Females were attracted to the odor of (–)-fenchone while males had no preference. By contrast, all animals were indifferent to or did not smell the odor of S-(+)-carvone, (–)-citronellol, and (+)-fenchone. Further research to distinguish between these alternatives (indifference vs hyposmia/anosmia) is suggested.     

A dioestrous increase in thymocyte proliferation during the oestrous cycle

Summary Coitus, which precedes internal fertilisation, is a unique physiological event which allows motile allogeneic spermatozoa to enter the female host and invade her tissues. The cyclic cellular proliferation observed in the thymus of the female rat may be an important preparation of her immune system for this event.     

Brain nucleic acid content during the estrous cycle in the rat

Résumé Le contenu total du RNA, DNA et le poids sec de certaines parties prélevées au cerveau sont resté constants durant les différentes étapes du cycle oestral.

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Deceased.