14 research outputs found
Short-Term Enrichment Makes Male Rats More Attractive, More Defensive and Alters Hypothalamic Neurons
Innate behaviors are shaped by contingencies built during evolutionary history. On the other hand, environmental stimuli play a significant role in shaping behavior. In particular, a short period of environmental enrichment can enhance cognitive behavior, modify effects of stress on learned behaviors and induce brain plasticity. It is unclear if modulation by environment can extend to innate behaviors which are preserved by intense selection pressure. In the present report we investigate this issue by studying effects of relatively short (14-days) environmental enrichment on two prominent innate behaviors in rats, avoidance of predator odors and ability of males to attract mates. We show that enrichment has strong effects on both the innate behaviors: a) enriched males were more avoidant of a predator odor than non-enriched controls, and had a greater rise in corticosterone levels in response to the odor; and b) had higher testosterone levels and were more attractive to females. Additionally, we demonstrate decrease in dendritic length of neurons of ventrolateral nucleus of hypothalamus, important for reproductive mate-choice and increase in the same in dorsomedial nucleus, important for defensive behavior. Thus, behavioral and hormonal observations provide evidence that a short period of environmental manipulation can alter innate behaviors, providing a good example of gene-environment interaction
Preventive and therapeutic challenges in combating Zika virus infection: are we getting any closer?
Consistent patterns of common species across tropical tree communities
Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations 1–6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories 7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees
Effects of Crotalus durissus collilineatus venom in the isolated rat kidney
Ophidian accidents caused by the subspecies Crotalus durissus are responsible for high morbity and mortality rates. Acute renal failure is a common complication observed in these accidents. The aim of the present study was to investigate the renal effects promoted by the venom of C. d. collilineatus and its fractions, crotoxin and phospholipase A, C. d. collilineatus (Cdc; 30 mu g mL(-1)), crotoxin (CTX; 10 mu g mL(-1)) and phospholipase A(2) (PLA(2); 10 mu g mL(-1)) were tested in isolated rat kidney. The first 30 min of each experiment were used as an internal control and Cdc or its fractions, CTX and PLA(2) were added to the system after this period. All experiments lasted 120 min. The venom of Cdc decreased perfusion pressure (PP; control(120) = 110.3 +/- 3.69 mmHg; Cdc(120) = 96.7 +/- 8.1 mmHg), renal vascular resistance (RVR; control(120) = 6.42 +/- 0.78 mmHg mL g(-1) min(-1); Cdc(120) = 4.8 +/- 0.56 mmHg/mL g(-1) min(-1)), urinary flow (UF; control(120) = 0.19 +/- 0.03 mL g(-1) min(-1); Cdc(120) = 0.12 +/- 0.01 mL g(-1) min(-1)), and glomerular filtration rate (GFR; control(120) = 0.79 +/- 0.07 mL g(-1) min(-1); Cdc(120) = 0.53 +/- 0.09 mL g(-1) min(-1)), but had no effect on the percent of sodium tubular transport (%TNa+), percent of chloride tubular transport (%TK+) and percent of potassium tubular transport (%TCl-). CTX and PLA(2) reduced the GFR, while UF, PP and RVR remained stable during the full 120 min of perfusion. Crotoxin administration also diminished the %TK+ (control(120) = 69.94 +/- 6.49; CTX120 = 33.28 +/- 4.78) and %TCl- (control(120) = 79.53 +/- 2.67; CTX120 = 64.62 +/- 6.93). PLA(2) reduced the %TK+, but exerted no effect on the %TNa+ or on that of TCl-. In conclusion, the C. d. collilineatus venom altered the renal functional parameters evaluated. We suggest that crotoxin and phospholipase A(2) were involved in this process, since the renal effects observed would be due to the synergistic action of the components of the venom. (c) 2005 Elsevier Ltd. All rights reserved.47326026
Profile of paediatric rheumatology specialists and services in the state of Sao Paulo
Introduction: Paediatric rheumatology (PR) is an emerging specialty, practised by a limited number of specialists. Currently, there is neither a record of the profile of rheumatology patients being treated in Brazil nor data on the training of qualified rheumatology professionals in the country. Objective: To investigate the profile of PR specialists and services, as well as the characteristics of paediatric patients with rheumatic diseases, for estimating the current state of rheumatology in the state of Sao Paulo. Patients and methods: In 2010, the scientific department of PR of the Paediatric Society of Sao Paulo administered a questionnaire that was answered by 24/31 accredited specialists in PR practising in state of Sao Paulo and by 8/21 institutions that provide PR care. Results: Most (91%) of the surveyed professionals practise in public institutions. Private clinics (28.6%) and public institutions (37.5%) reported not having access to nailfold capillaroscopy, and 50% of the private clinics reported not having access to acupuncture. The average duration of professional practise in PR was 9.4 years, and 67% of the physicians had attended postgraduate programmes. Seven (87.5%) public institutions perform teaching activities, in which new paediatric rheumatologists are trained, and five (62.5%) offer post-graduate programmes. Two-thirds of the surveyed specialists use immunosuppressants and biological agents classified as "restricted use" by the Health Secretariat. The disease most frequently reported was juvenile idiopathic arthritis (29.1-34.5%), followed by juvenile systemic lupus erythematosus (JSLE) (11.6-12.3%) and rheumatic fever (9.1-15.9%). The incidence of vasculitis (including Henoch-Schonlein purpura, Wegener's granulomatosis, and Takayasu's arteritis) and autoinflammatory syndromes was higher in public institutions compared to other institutions (P = 0.03, P = 0.04, P = 0.002, and P < 0.0001, respectively). Patients with JSLE had the highest mortality rate (68% of deaths), mainly due to infection. Conclusion: The field of PR in the state of Sao Paulo has a significant number of specialists with postgraduate degrees who mostly practise at teaching institutions with infrastructures appropriate for the care of high-complexity patients. (C) 2013 Elsevier Editora Ltda. All rights reserved.53434635