Saving for your future self: The role of imaginary experiences

Despite increased longevity, many people fail to save the funds necessary to support their retirement. In an attempt both to elucidate and remedy this failing, research exploring the “future-self continuity” hypothesis has revealed that temporal discounting is decreased and saving increased when connections between one’s current and future self are strengthened. Here, we explored the possibility that a basic component of mental imagery–spatial visual perspective–may be an important determinant of people’s decisions to spend now or save for the future. The results of two experiments supported this prediction. Rates of saving were enhanced when a distant-future event was generated from a third-person vs. first-person vantage point, an effect that was mediated by visual bodily awareness during mental imagery

5alpha-reductase 2 inhibition impairs brain defeminization of male rats: Reproductive aspects

The present study was carried out to determine whether 5alpha-reductase 2 (5alpha-R2) metabolic pathway plays a key role in brain sexual differentiation. The inhibition of 5alpha-R2 by finasteride (20 mg/kg/day) from gestational day 19 to postnatal day 5 has long-term effects on sexual behavior and reproductive physiology detected only in adult life. Sexual maturation assessed by timing of preputial separation was unchanged. Finasteride-treated males were able to mate with untreated females which became pregnant but exhibited increased rate of pre-implantation loss. The subfertility observed was probably due to abnormally shaped sperm, since the sperm number was not altered. While plasma testosterone was enhanced, LH levels were not changed. The copulatory potential was not affected and all finasteride-treated rats presented male sexual behavior. Despite this, 53% of them showed homosexual behavior when pretreated with estradiol, suggesting an incomplete brain defeminization. These results indicate that 5alpha-R2 acts in brain sexual differentiation of male rats. Moreover, we suggest that 5alpha-R2 not only produces essential metabolites that act together with estradiol in brain sexual differentiation but also protects the brain from the damaging effects of estradiol excess. (c) 2005 Elsevier B.V. All rights reserved

Noradrenergic response in vas deferens from rats submitted to acute and repeated stress

1. This work investigated the effects of androgens on the norepinephrine sensitivity of vasa deferentia from rats submitted to acute or repeated stress, as well as the participation of alpha(1)-adrenoceptors in the response of intact and bisected vasa deferentia from adult normal rats submitted to acute or repeated stress.2. The acute stress produced subsensitivity to norepinephrine only in intact vasa deferentia from adult normal rats, which was prevented by lack of androgens, suggesting that the sensitivity may be dependent on the physiological level of androgen,3. No change was observed in intact vas deferens sensitivity to norepinephrine in repeated stress, suggesting the occurrence of adaptation to elevated norepinephrine levels or a mild decrease in androgen levers or both.4. The changes in sensitivity observed in acute and repeated stress may also be due to alterations in alpha(1)-adrenergic receptors that are located in the prostatic portion of the vas deferens. (C) 1998 Elsevier B.V

Neuroendocrine and reproductive aspects of adult male rats exposed neonatally to an antiestrogen

The present study was designed to investigate the effects of a single dose of an estrogen antagonist-clomiphene-during neonatal life, on later neuroendocrine system and reproductive performance. Immediately after birth, male pups received clomiphene citrate (s.c.). At adulthood, although testosterone levels and wet weights of reproductive organs were not altered, the treatment induced an increased number of spermatozoa and a delay in the transit time in the cauda epididymis. Additionally, there was impairment of sexual behavior evidenced by a delay in the latencies to the first mount and first intromission. Treated rats also showed decreased dopaminergic and serotonergic neurotransmissions in the hypothalamus and decreased dopaminergic neurotransmission in the striatum. The decreased dopaminergic activity could be related to the lower sexual motivation observed. These results indicate the necessity of preventing exposure to drugs that may impair sexual differentiation, which can compromise later mating success as well as the capacity to generate descendants. (c) 2006 Elsevier B.V. All rights reserved

Sexual behavior, neuroendocrine, and neurochemical aspects in male rats exposed prenatally to stress

The present study was designed to examine some short- and long-term effects of maternal restraint stress-during the period of sexual brain differentiation-on reproductive and endocrine systems, sexual behavior, and brain neurotransmitters in male rat descendants. Pregnant rats were exposed to restraint stress for 1 h/day from gestational days (GDs) 18 to 22. Prenatal stress did not influence the wet weight of sexual organs and the quantity of germ cells in adult male pups; however, these animals showed reduced testosterone levels, delayed latency to the first mount and first intromission, and also decreased number of ejaculations. Additionally, there was an increase in the dopamine and serotonin levels in the striatum. Our results indicate that prenatal stress had a long-term effect on neurotransmitter levels and sexual behavior. In this sense, reproductive problems caused by injuries during the fetal period can compromise the later success of mating as well as the capacity to generate descendants. (C) 2004 Elsevier B.V. All rights reserved

Human VPS13A is associated with multiple organelles and influences mitochondrial morphology and lipid droplet motility

The VPS13A gene is associated with the neurodegenerative disorder Chorea Acanthocytosis. It is unknown what the consequences are of impaired function of VPS13A at the subcellular level. We demonstrate that VPS13A is a peripheral membrane protein, associated with mitochondria, the endoplasmic reticulum and lipid droplets. VPS13A is localized at sites where the endoplasmic reticulum and mitochondria are in close contact. VPS13A interacts with the ER residing protein VAP-A via its FFAT domain. Interaction with mitochondria is mediated via its C-terminal domain. In VPS13A-depleted cells, ER-mitochondria contact sites are decreased, mitochondria are fragmented and mitophagy is decreased. VPS13A also localizes to lipid droplets and affects lipid droplet motility. In VPS13A-depleted mammalian cells lipid droplet numbers are increased. Our data, together with recently published data from others, indicate that VPS13A is required for establishing membrane contact sites between various organelles to enable lipid transfer required for mitochondria and lipid droplet related processes

Iterated exaptation

This volume focuses on detailed studies of various aspects of Construction Morphology, and combines theoretical analysis and descriptive detail.status: publishe