Effects of SKF-83566 and haloperidol on performance on progressive ratio schedules maintained by sucrose and corn oil reinforcement: quantitative analysis using a new model derived from the Mathematical Principles of Reinforcement (MPR)

Rationale Mathematical models can assist the interpretation of the effects of interventions on schedule-controlled behaviour and help to differentiate between processes that may be confounded in traditional performance measures such as response rate and the breakpoint in progressive ratio (PR) schedules. Objective The effects of a D1-like dopamine receptor antagonist, 8-bromo-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepin-7-ol hydrobromide (SKF-83566), and a D2-like receptor antagonist, haloperidol, on rats’ performance on PR schedules maintained by sucrose and corn oil reinforcers were assessed using a new model derived from Killeen’s (Behav Brain Sci 17:105–172, 1994) Mathematical Principles of Reinforcement. Method Separate groups of rats were trained under a PR schedule using sucrose or corn oil reinforcers. SKF-83566 (0.015 and 0.03 mg kg−1) and haloperidol (0.05 and 0.1 mg kg−1) were administered intraperitoneally (five administrations of each treatment). Running and overall response rates in successive ratios were analysed using the new model, and estimates of the model’s parameters were compared between treatments. Results Haloperidol reduced a (the parameter expressing incentive value) in the case of both reinforcers, but did not affect the parameters related to response time and post-reinforcement pausing. SKF-83566 reduced a and k (the parameter expressing sensitivity of post-reinforcement pausing to the prior inter-reinforcement interval) in the case of sucrose, but did not affect any of the parameters in the case of corn oil. Conclusions The results are consistent with the hypothesis that blockade of both D1-like and D2-like receptors reduces the incentive value of sucrose, whereas the incentive value of corn oil is more sensitive to blockade of D2-like than D1-like receptors

Activation of serotonin neurons promotes active persistence in a probabilistic foraging task

Serotonin (5-HT) has been suggested to promote waiting through behavioral inhibition. Here, the authors use an active foraging task and optogenetic activation of 5-HT neurons to show that rather than passivity, these neurons enhance persistence in the face of delay

¿Ángeles en la batalla?: Representaciones de la enfermera en Champourcin y Urraca Pastor durante la guerra civil española

Durante la Guerra Civil Espanola (1936-39), tanto en el bando republicano como en el sublevado numerosas mujeres se ofrecieron como voluntarias para cuidar a los heridos, incluso careciendo de experiencia previa en cuestiones sanitarias. En palabras de Mary Nash, en la retaguardia y en las trincheras la enfermería era uno de los ámbitos más importantes de la movilización femenina (Rojas 215). Esto explica que desde el inicio del conflicto bélico la figura de la enfermera se mitificara, creándose romances y carteles en torno a ella (Greene 128). En opinión de Miriam Basilio, la imagen de la enfermera en h España republicana, junto con otras figuras femeninas tradicionales como las madres o las costureras, sirvió para contrarrestar las ansiedades masculinas producidas por la presencia de mujeres en el frente o en las fábricas (34)