Novelty reward as a measure of anhedonia

Ablation of Neuronal Ceramide Synthase 1 in Mice Decreases Ganglioside Levels and Expression of Myelin-associated Glycoprotein in Oligodendrocytes

“…Novel Object Exploration Test-Each animal was allowed to freely explore two copies of a novel object placed into two randomly selected corners of a familiar open field (37,38). Objects were made of plastic, had a textured surface, and had a height of 18 cm.…”

The role of histamine receptors in the consolidation of object recognition memory

“…This paradigm is especially suited to test the effects of pharmacological interventions on learning and memory (Dere, Huston, & De Souza Silva, 2007). Novelty induces arousal and has motivational effects that are used as a reinforcement to induce learning (Bevins & Besheer, 2005). Multiple brain structures, as well as multiple neurotransmitter/neuromodulators like histamine are involved in the induction and regulation of arousal and its behavioral consequences (Miller & O'Callaghan, 2006;Passani & Blandina, 2011;Passani, Giannoni, Bucherelli, Baldi, & Blandina, 2007).…”

Desensitization of δ-opioid receptors in nucleus accumbens during nicotine withdrawal

“…For example, DOPrs are involved in the anxiety-like behaviors of acute nicotine (Balerio et al 2005), δ-agonists attenuate mecamylamine-precipitated nicotinewithdrawal aversion (Ise et al 2000), and δ-antagonists have some effect on nicotine self-administration (Ismayilova and Shoaib 2010). Despite differences in nicotine treatment schedules, our studies and these in literature show a temporal overlap of DOPr desensitization with anhedonia (EppingJordan et al 1998;Bevins and Besheer 2005;Johnson et al 2008), anxiety (Costall et al 1989;Stoker et al 2008), and depression-like behavior (Zaniewska et al 2010) in nicotine withdrawal, which could imply a link between negative affective symptoms and δ-signaling dysregulation in NAc. In contrast to DOPrs, the coupling of MOPrs to G-proteins appears to be normal in NAc, especially shell, in early nicotine withdrawal, suggesting that MOPrs might not be involved in the reward deficits associated with this stage of nicotine addiction.…”