Effects of consuming a diet high in fat and/or sugar on the locomotor effects of acute and repeated cocaine in male and female C57BL/6J mice.

Abstract

Drug abuse and obesity are serious public health problems. Dopamine plays a central role in mediating the reinforcing effects of drugs and food. Prolonged use of drugs is known to alter the function and/or sensitivity of many neurotransmitter systems, including dopamine, however, the impact of consuming foods high in fat and/or sugar is less clear. These studies characterized the locomotor effects of acute and repeated cocaine in male and female C57BL/6J mice consuming one of four diets: (1) standard chow + water; (2) standard chow + 10% sucrose solution; (3) high-fat chow + water; or (4) high-fat chow + 10% sucrose solution. The acute locomotor effects of cocaine (3.2–32.0 mg/kg) were evaluated four weeks after initiating dietary conditions; the effects of repeated cocaine administration were evaluated after 5, 6, 7, and 12 weeks. During acute tests, mice consuming a diet high in fat and/or sucrose exhibited greater locomotor responses to cocaine than mice consuming standard chow and water, regardless of sex. Although diet-induced enhancements persisted across repeated cocaine testing, locomotor sensitization developed more rapidly in females drinking sucrose (and consuming either standard or high-fat chow) than in females consuming standard chow and water. In addition to providing evidence that consuming a diet high in fat and/or sugar enhances abuse-related effects of cocaine in ways that might increase vulnerability to abuse cocaine, these studies identified a potentially important sex-related difference in the interaction between nutrition and cocaine effects, with the impacts of sucrose consumption being greater in females than in males.

Modulatory effects of Ampicillin/Sulbactam on glial glutamate transporters and metabotropic glutamate receptor 1 as well as reinstatement to cocaine-seeking behavior

“…injections of cocaine induced place preference and increased locomotor activity as well as that cocaine CPP was extinguished after eight saline i.p. injection (24, 61, 75–79). The acute locomotor responses to drugs of abuse, including cocaine, are mainly dependent on the mesolimbic and nigrostriatal dopaminergic systems, which are known to be regulated by the glutamatergic system (80).…”

Responses to drugs of abuse and non-drug rewards in leptin deficient ob/ob mice

“…This is unlikely to be related to the increase in food intake/body weight, as diet-induced obese mice were found to have reduced cocaine CPP (Morales et al 2012). Similarly, increased food intake/body weight likely does not explain the lack of locomotor effects of cocaine, as cocaine-induced locomotor activity is increased in mice fed high fat and/or high sugar diets (Collins et al 2015; Olsen 2011). …”

Short post‐weaning social isolation induces long‐term changes in the dopaminergic system and increases susceptibility to psychostimulants in female rats

“…Westenbroek et al (2013) evidenced that isolated females show higher motivation for cocaine seeking than their male counterparts, and a higher risk for escalation of drug use. In addition, females are more vulnerable to sucrose reward effect than males (Collins et al, 2015).…”

“…Studies have demonstrated that neurobiological and behavioral responses to stress (Trainor, 2011) and to sucrose intake (Collins et al, 2015) are frequently sex dependent. Women appear to be more vulnerable to drugs of abuse than men (Bertholomey et al, 2016;Bobzean et al, 2014;Carroll and Anker, 2010).…”