Disturbed behavioural adaptability as related to reproductive hormones and emotional states during the menstrual cycle

The relationship between the incapacity to adapt behaviour to external requirements and biological irregularities of the menstrual cycle was investigated in 30 healthy females divided according to a questionnaire on behavioural adaptability into good (GAs) and bad (BAs) adaptors. Emotional states and blood samples for determination of hormones were obtained on ten defined days of the menstrual cycle, which were individually synchronized to six phases according to biological indicators. Comparison of GAs and BAs revealed that the incapacity of behavioural adaptation is associated with higher neuroticism related traits and states and that BAs exhibited higher cortisol and testosterone levels, lower luteal and follicular levels of estrogen, and lower luteal levels of progesterone. Furthermore, significantly more BA subjects suffered from corpus luteum deficiency. Results are discussed with respect to chronobiological biobehavioural mechanisms. © 1998 John Wiley & Sons, Ltd.     

Contrasting activity patterns of two related octopus species, Octopus macropus and Octopus vulgaris

Octopus macropus and Octopus vulgaris have overlapping habitats and are exposed to similar temporal changes. Whereas the former species is described as nocturnal in the field, there are conflicting reports about the activity time of the latter one. To compare activity patterns, the authors tested both species in the laboratory. Octopuses were exposed to a light-dark cycle and held under constant dim light for 7 days each. O. macropus showed nocturnal and light-cued activity. According to casual observations, O. vulgaris started out nocturnal but had switched to mostly diurnal when the experiment began. Individual variation of its activity was found. The different activity patterns of O. macropus and O. vulgaris might reflect their lifestyles, the latter species being more generalist.