Impairment of renal urinary excretion in neonatal, but not in adult capsaicin-pretreated rats.

The effect of saline and/or water load on diuresis, natriuresis and kaliuresis in control and in neonatal or adult capsaicin-pretreated awake rats has been assessed. Urine was collected by means of metabolic cages or intra-abdominally from a previously catheterized ureter. Neonatal but not adult capsaicin-pretreated animals exhibited a remarkable reduction in volume of urine output and in electrolytes excretion. This effect was more evident following saline as compared to water load. Similar results were also obtained when urine was directly collected from the ureters, suggesting that pharmacological ablation, at neonatal stage, of a subset of capsaicin-sensitive sensory nerves could impair the excretory kidney function

Reviewing stranger on the internet: The role of identifiability through “reputation” in online decision making

The stranger on the Internet effect has been studied in relation to self-disclosure. Nonetheless, quantitative evidence about how people mentally represent and perceive strangers online is still missing. Given the dynamic development of web technologies, quantifying how much strangers can be considered suitable for pro-social acts such as self-disclosure appears fundamental for a whole series of phenomena ranging from privacy protection to fake news spreading. Using a modified and online version of the Ultimatum Game (UG), we quantified the mental representation of the stranger on the Internet effect and tested if people modify their behaviors according to the interactors’ identifiability (i.e., reputation). A total of 444 adolescents took part in a 2 × 2 design experiment where reputation was set active or not for the two traditional UG tasks. We discovered that, when matched with strangers, people donate the same amount of money as if the other has a good reputation. Moreover, reputation significantly affected the donation size, the acceptance rate and the feedback decision making as well

Conditioned taste aversion induced by ethanol in alcohol-preferring rats: influence of the method of ethanol administration.

A recent study of our group has shown that ethanol evokes conditioned place preference (CPP) in Marchigian Sardinian alcohol-preferring (msP) rats following intragastric (IG) administration by means of an indwelling IG catheter, but not following administration by gavage or by intraperitoneal (IP) injection. The present study evaluated in ethanol-naive msP rats the influence of the method of administration (IG injection by indwelling catheter vs. IP injection) on ethanol-induced conditioned taste aversion (CTA). The dose of 0.35 g/kg of ethanol did not evoke aversion either by IG or by IP administration. Following IG injection, 0.7 g/kg of ethanol, the amount that msP rats voluntarily ingest in a short (2-5 min) drinking episode, did not evoke CTA, and 1.5 g/kg induced a modest CTA. On the other hand, IP injection of 0.7 g/kg of ethanol evoked CTA, and 1.5 g/kg induced a very pronounced CTA. These findings show that the aversive properties of ethanol in msP rats are influenced by the method of administration, and suggest that the IG injection by catheter may reveal more faithfully than the IP injection the motivational properties of amounts of ethanol that alcohol-preferring rats voluntarily ingest

Effect of capsaicin neonatal treatment on the salt intake of the adult rat.

The present study investigated the involvement of capsaicin-sensitive sensory neurons on salt intake control in the rat, following capsaicin neonatal treatment. Capsaicin did not affect salt appetite induced by intramuscular injection of deoxycorticosterone enantate, or by intracranial injection of renin. Moreover, it did not alter salt preference of rats given access to a variety of NaCl concentrations, or the need-free salt intake of multidepleted male rats. On the other hand, in response to furosemide-induced sodium depletion, the salt intake of capsaicin-treated rats was lower than that of controls. However, furosemide-induced Na+ excretion of capsaicin-treated rats proved to be lower than that of controls, thus suggesting that difference in salt intake might be secondary to lower sensitivity of capsaicin-treated rats to the natriuretic action of furosemide. Salt intake is known to be influenced by sensory information from the oral cavity, from the liver and from the intravascular compartment. The absence of effect of capsaicin neonatal treatment suggests that sensory fibers relevant to salt intake control may not be capsaicin sensitive. On the other hand, our findings indicate that capsaicin treatment alte

Expression of substance p and its neurokinin-1 receptor on thymocytes: functional relevance in the regulation of thymocyte apoptosis and proliferation.

Herein, we provide evidence of the expression and function of substance P (SP) and neurokinin-1 receptor (NK-1R) in the rat thymus. In situ hybridization evidenced NK-1R mRNA mainly in the thymic medulla, and Northern blot analysis of mRNA from FACS-sorted thymocytes identified NK-1R on CD4+, CD8+ and double-positive subpopulations. With flow cytometry, it could be seen that NK-1R was expressed on the majority of CD5+ thymocytes, and it was identified by Western blot analysis as two bands migrating at 44 and 54 kD. SP administration rescues thymocytes from spontaneous and NK-1R antagonist (SR140333)-induced apoptosis and stimulates concanavalin A (ConA)-induced thymocyte proliferation, CD25 expression and IL-2 production, whereas SR140333 exerts inhibitory effects on these functions. We also demonstrated the expression of mRNA for the SP precursor preprotachykinin-A in the thymic medulla and purified CD5+ thymocytes. SP protein was detected on 40% of CD5+ thymocytes and identified as a band of 1.3 kD by Western blot analysis. Finally, thymocytes spontaneously released SP, which was increased upon ConA or CD3 stimulation