Short term aerobic exercise training in young males does not alter sensitivity to a central serotonin agonist

An increase in the concentration of serotonin in the brain has been shown to cause fatigue during exercise in humans and experimental animals. This type of fatigue is referred to as central fatigue and is likely to be mediated by the concentration of serotonin as well as serotonin receptor sensitivity. Serotonin (5-HT) receptor antagonism in humans and experimental animals has been shown to improve endurance performance. A previous report has shown decreased receptor sensitivity in athletes compared to sedentary controls. It is unclear whether this is due to a training adaptation or if individuals are predisposed to enhanced athletic performance due to their inherent decreased receptor sensitivity. The present study investigated changes in 5-HT receptor sensitivity in response to aerobic exercise. Subjects completed 3 × 30 min of stationary cycling at 70% of their peak aerobic power (V̇O2,peak) for 9 weeks. Serotonin receptor sensitivity was assessed indirectly by measuring the neuroendocrine response following administration of a serotonin agonist (buspirone hydrochloride). The neuroendocrine response following administration of a placebo was also investigated in a blind crossover design. A group of sedentary control subjects was also recruited to control for seasonal variations in central receptor sensitivity. The training caused a significant increase in V̇O2,peak (3.1 ± 0.16 to 3.6 ± 0.15 l min−1, P < 0.05) and endurance capacity (93 ± 8 to 168 ± 11 min, P < 0.05), but there was no change (P > 0.05) in the neuroendocrine response in the presence of a serotonin agonist. However, one-quarter of the subjects in the training group demonstrated decreases in receptor sensitivity. These results suggest that despite increases in V̇O2,peak and endurance performance, there was no measurable change in 5-HT receptor sensitivity in the presence of a serotonin agonist. In addition, it is possible that changes in receptor sensitivity may take longer to occur, that the training stimulus used in the present investigation was inadequate and/or that changes occurred in receptor subtypes that were not probed by the agonist used in the present investigation.

Daemons & deities

Solo exhibition of works by Deborah Walker exhibited at 69 Smith Street Gallery, and a related survey & biography written by independent arts writer, Gillian Wills

Exploring subject positions and multiple temporalities through an Iranian migrant mother's family photograph albums

 In this article, I draw on a research study of one Iranian migrant mother's generation of selves through her material configuration of her personal photograph albums and through our verbal reading of her photographs. The research engages in a visual-material feminist ethnographic approach, and is informed by the work of Gillian Rose and the understanding that family photographs are a means by which women negotiate subject positions. In this article, I discuss an unexpected finding of my research, the significance of multiple temporalities in a migrant mother's production of selves. The photo album practices of the participant mother of this study, ‘Parvin’, depart from the common social convention of mothers arranging their photograph albums to chart family growth following the model of milestones occurring over linear developmental time. Parvin does not limit herself to linear developmental time, but rather she mixes up photographs in her post-migration family albums to generate multiple temporalities woven together by an enveloping ‘mixed’ time. Drawing on both Julia Kristeva and Homi Bhaba's theories of temporality and the subject, I suggest that Parvin produces subject positions for self and family through a continual interweaving of a multitude of pasts into the present and through a subsuming of milestones within cyclical family time. Further, I suggest that through her generation of multiple temporalities, Parvin produces the subject position of ‘accommodating mother’. Finally, I highlight the potential afforded by considering the temporal and the spatial together in studies of migrant identity.