“A differential-reinforcement-of-low-rate

schedule


“A differential-reinforcement-of-low-rate

schedule (DRL) delivers reinforcement only when the interresponse time (IRT) exceeds a fixed time interval, thereby shaping rats to discriminate the timing of their responses. However, little is known about the motor behavior and location of the rats in the chamber during the IRTs that lead to reinforcement. Although amphetamine is known to disrupt DRL timing behavior, the effects of this drug on non-operant motor behavior during DRL performance has not yet been quantified.\n\nThe purpose of this research was to measure the motor behavior (movement trajectories in the horizontal plane and spatial location in the plane) during longer IRTs after either vehicle or amphetamine treatment.\n\nExperimental chambers were constructed with a force-plate actometer as the floor, and while performing the operant task, the rats’ 5-Fluoracil clinical trial motor behaviors were measured continuously with high temporal and spatial resolution. Separate groups of eight male Sprague-Dawley rats were maintained on either DRL 24-s or DRL 72-s schedules of water reinforcement in 4-h recording sessions.\n\nAnalyses of

IRT distributions showed that the rats’ timing behavior conformed to their respective DRL requirements. In the absence of drug, analysis of motor behavior in pre-reinforcement intervals showed that rats located themselves away from the operandum and exhibited very low levels of movement. Rats exhibited a significant temporal diminution of horizontal movement that reached a minimum PLK inhibitor 4-8 s BTSA1 inhibitor before the rats moved to the operandum to execute operant responses. Amphetamine treatment increased locomotion, abolished the temporal movement gradient, and brought the rats closer to the operandum compared to vehicle treatment. Movement changes induced by amphetamine were accompanied by degraded timing behavior.\n\nTaken together, the data show that DRL training induced rats to locate themselves away from the operandum and to remain nearly motionless during longer IRTs and that amphetamine treatment interfered with this complex of behavioral features.”
“Autosomal dominant polycystic kidney disease (ADPKD) is characterized by age-dependent

growth of kidney cysts with end-stage renal disease developing in approximately 50% of affected individuals. Living donors from ADPKD families arc at risk for developing ADPKD and may be excluded from renal donation if the diagnosis cannot be conclusively ruled out. Radiographic imaging may be adequate to screen for kidney cysts in most at-risk donors but may fail to identify affected individuals younger than 40 years or older individuals from families with mild disease. In this article, we report a strategy that incorporates genetic testing in the evaluation of live kidney donors at risk for ADPKD whose disease status cannot be established with certainty on the basis of imaging studies alone. We show that DNA diagnostics can be used to enhance safe donation for certain living donor candidates at risk for ADPKD.

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