Topic: progressive ratio

Obesity has emerged as a prominent global health concern in recent times, a phenomenon often attributed to the excessive consumption of highly palatable, calorie-rich foods laden with sugar and fat. These diets can modulate certain neural pathways, such as the mesolimbic dopaminergic system of reward, but their potential addictive properties are still unknown although its effects have been widely studied. Additionally, Δ9-tetrahydrocannabinol (THC), the main psychoactive component of cannabis sativa, has been found to have an important orexigenic role and modulating properties over the reward

Genetically selected Marchigian Sardinian alcohol-preferring (msP) rats exhibit a dysregulation of the opioid system in several brain areas and show innate psychiatric traits comorbid with drug abuse. Therefore, we hypothesized that, similar to alcohol, msP would display increased preference for heroin compared to non-preferring Wistar controls. Thus, we compared the heroin self-administration (HSA) dose/response (1, 7, 20, 60 µg/infusion) curves of msP and Wistar rats under fixed-ratio 1(FR1) and progressive ratio (PR) contingencies. Male msP rats, showed increased HSA at intermediate doses u

The level of dietary protein is expected to be crucial for food preference because of its essential role in maintaining homeostasis. Here, we used Feeding Experimentation Devices (FED3s) to assess food preference and foraging behaviour of protein-restricted vs. control mice. Details are shown in graphical methodology; briefly, adult C57BL/6NRj mice were maintained either on protein-restricted (5% casein: PR) or non-restricted diet (20% casein: NR). Food-preference was tested in four 3-days-apart choice sessions each lasting 24h during which mice were individually placed in a cage with access t