A reassessment of the role of serotonergic system in the control of feeding behavior

The role of serotonergic system in the feeding behaviorwas appraised by electrolytic lesions in the dorsal raphe nucleus (DRN) and administration of para-chlorophenylalanine (PCPA, 3 mg/5 mul, icv). Chronic evaluations were accomplished through 120 and 360 days in PCPA-injected and DRN-lesioned rats, respectively. Acute food intake was evaluated in fasted rats and submitted to injection of PCPA and hydroxytryptophan (LHTP, 30 mg/kg, ip). DRN-lesioned rats exhibited 22-80% increase in food intake up to sixth month, whereas the obesity was evident and sustained by whole period. In PCPA-injected rats was observed an initial increase in the food intake followed by hypophagy from 25th to 30th day and a transitory increase of body weight from 5th to 60th day. In the acute study, the LHTP reverted partially the PCPA-induced increase in food intake of fasted rats suggesting a sustained capacity of decarboxylation of precursor by serotonergic neurons. Slow restoration of the levels of food intake in DRN-lesioned rats reveals a neuroplasticity in the systems that regulate feeding behavior. A plateau on the body weight curve in lesioned rats possibly represents the establishment of a new and higher set point of energetic balance

Brain serotonin depletion enhances the sodium appetite induced by sodium depletion or beta-adrenergic stimulation

We investigate the influence of brain serotonin depletion on the sodium appetite. Rats depleted of serotonin through the systemic administration of p-chlorophenylalanine (300 mg/kg, ip, for 2 days) showed an intense natriorexigenic response induced by sodium depletion (furosemide, 20 mg/kg, sc, 24 h before water and 1.8% NaCl presentation). Intake of 1.8% NaCl was always higher than that observed for the control group (12.9 ± 1.4 and 21.4 ± 3.0 mL vs 5.7 ± 1.2 and 12.7 ± 1.6 mL, 30 and 300 min after water and saline presentation). After 24 h, the natriorexigenic response continued to be significantly higher compared to control (33.6±5.1 vs 21.9±3.6 mL,P <0.05). Fourteen days after p-chlorophenylalanine administration, 1.8% NaCl intake did not differ from controls. Serotonin-depleted rats expressed an early natriorexigenic response after isoproterenol administration on the third day after the first injection of p-chlorophenylalanine. An increase in 1.8% NaCl intake was first observed at 120 min (1.9 ± 0.2 vs 0.45 ± 0.3 mL,P <0.05) and remained high up to the end of the 24-h observation period (17.3±3.2 vs 1.1±0.5 mL,P <0.05). After 7 and 14 days, the natriorexigenic response became comparable to that of control animals. Present results show that brain serotonin depletion exaggerates the sodium appetite induced by the paradigm of sodium depletion or after beta-adrenergic stimulation

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora