Dopamine antagonists alter response allocation but do not suppress appetite for food in rats: contrast between the effects of SKF 83566, raclopride, and fenfluramine on a concurrent choice task

Abstract

Dopamine antagonists and accumbens dopamine depletions do not simply reduce appetite. Rats with accumbens dopamine depletions, or rats treated with low doses of selective or non-selective dopamine antagonists, remain directed toward the acquisition and consumption of food. These results demonstrate that fundamental aspects of food reinforcement are left intact after treatment with low doses of dopamine antagonists.

Baclofen, raclopride, and naltrexone differentially reduce solid fat emulsion intake under limited access conditions

“…The failure of raclopride to reduce chow intake in the present study is consistent with other reports in which chow intake was either unaffected or stimulated by peripheral raclopride at dosages that had other behavioral effects (e.g. Lutz, et al, 2001;Salamone, et al, 2002).…”

Systemic administration of the adenosine A2A agonist CGS 21680 induces sedation at doses that suppress lever pressing and food intake

“…greater than 1000 lever presses in 30 min) that is very sensitive to the response suppressant properties of drugs (Chuck et al, 2006;Salamone et al, 1993a). This schedule has been shown to be highly sensitive to the rate-decreasing effects of several classes of drugs, including DA antagonists (Salamone et al, 1993a(Salamone et al, , 2002, the acetylcholinesterase inhibitor tacrine (Carriero et al, 1998), cannabinoid CB1 agonists (Arizzi et al, 2004;Carriero et al, 1998;McLaughlin et al, 2005a) and ethanol (Chuck et al, 2006). In the second experiment, rats were observed in 30 min sessions that allowed for the measurement of food intake, time spent feeding, and feeding rate.…”

Effort-Related Motivational Effects of the VMAT-2 Inhibitor Tetrabenazine: Implications for Animal Models of the Motivational Symptoms of Depression

“…Effort-based decision making is studied with tasks offering choices between high effort options leading to highly valued reinforcers versus low effort/low reward options. In animal studies, such tasks include operant procedures offering choices between responding on ratio schedules for preferred reinforcers versus approaching and consuming a less preferred food (Salamone et al, , 2002, a T-maze barrier crossing task Mott et al, 2009;, and effort discounting Bardgett et al, 2009). Considerable research has focused on the effort-related functions of dopamine (DA) systems, particularly accumbens DA.…”

“…Considerable research has focused on the effort-related functions of dopamine (DA) systems, particularly accumbens DA. Across multiple tasks, low doses of DA antagonists and accumbens DA depletions or antagonism shift choice behavior, decreasing selection of high effort/high reward options, and increasing selection of low effort/low reward choices (Salamone et al, , 1997 Nowend et al, 2001).People with depression and related disorders commonly show profound motivational impairments, including psychomotor retardation, anergia, lassitude, and fatigue, which can be highly resistant to treatment (Stahl, 2002; Bella et al, 2010). Tasks measuring effortbased functions have been suggested as potential models for these Received June 27, 2013; revised Oct. 11, 2013; accepted Oct. 15, 2013.…”

“…Moreover, tetrabenazine has frequently been used in studies involving animal models of depression (Preskorn et al, 1984;Kent et al, 1986; Wang et al, 2010). The present studies assessed the effort-related effects of tetrabenazine in rats using the concurrent fixed ratio 5 (FR5) lever-pressing/chow-feeding choice task (Salamone et al, , 2002. It was hypothesized that low systemic doses and intra-accumbens injections of tetrabenazine would alter choice behavior, decreasing lever pressing but increasing consumption of the concurrently available chow.…”