Effects of 6-hydroxydopamine lesions of the nucleus accumbens septi and olfactory tubercle on feeding, locomotor activity, and amphetamine anorexia in the rat.

Abstract

Bilateral 6-hydroxydopamine lesions of the nucleus accumbens septi (NAS) and olfactory tubercle (OT) caused enhanced intake of wet mash in 23-hrfood-deprived rats tested in photocell activity cages during restricted 30-min sessions. This mild hyperphagia was accompanied by a significant hypoactivity in the group with NAS/OT lesions. No hyperphagia was observed during a prolonged 120-min test session or in free-feeding tests conducted in the home cage. Anorexia induced by d-amphetamine (.5 and 1.5 mg/kg) was unaltered by the lesion, although the locomotor stimulant action of the drug was attenuated. A second experiment showed that the NAS/OT lesion also enhanced food intake in the photocell cages during 30-min sessions with dry food pellets but that food-associated drinking was concomitantly reduced. The results are consistent with the hypothesis that the behavioral changes caused by mesolimbic neuron destruction result in part from an inability to switch from one behavioral activity to another.

Striatal Dopamine Mediates the Interface between Motivational and Cognitive Control in Humans: Evidence from Genetic Imaging

“…The pattern is reminiscent of those observed in studies with rodents, in which effects of manipulating dopamine in the ventromedial striatum are more readily observed on preparatory than on consummatory behaviors (Robbins and Everitt, 1992;Salamone et al, 2007). Moreover, some studies have reported that consummatory responses can be attenuated by increases in dopamine (eg after amphetamine administration, which can have anorexic effects; eg Bakshi and Kelley, 1991; but see Kelley et al, 1989), and enhanced by decreases in dopamine (eg by 6-OHDA lesions; see Baldo and Kelley, 2007;Koob et al, 1978). Instead, it has been postulated that opioids directly modulate consummatory responses (Berridge and Robinson, 1998).…”

The adolescent brain and age-related behavioral manifestations

“…Indeed, acute intracortical injection of DA into frontal regions of adult rats has been reported to attenuate responsiveness to systemically administered stimulants [272] as well as to disrupt expression of sensitization to cocaine [435], data reminiscent of the similarly reduced response of adolescent rats to acute stimulant exposure [51,308,313,491,507,510,511] and attenuated expression of cocaine sensitization [507]. Likewise, adult rats with 6-OHDA lesions of DA input to ACC, like their normal adolescent counterparts (as discussed earlier), are hyperphagic [160,296], less sensitive to locomotor activating effects of psychomotor stimulant drugs [296], and exhibit problems adjusting to alterations in reward contingencies (see Ref. [317] for review and references).…”

Behavioral functions of the mesolimbic dopaminergic system: An affective neuroethological perspective

“…Experimentally enhanced DA function increases behavioral activity, whereas lesions of the ML-DA system reduce or eliminate exploratory and appetitive-approach behaviors (Koob et al, 1978;Fink & Smith, 1980;Robbins & Everitt, 1982;Taghzouti, 1985;Pierce et al, 1990;Pfaus & Phillips, 1991;Jones & Robbins, 1992;Liu et al, 1998). Pharmacological reduction of Nacc DA transmission inhibits seekingapproach behaviors in response to reward-associated cues (Blackburn et al, 1992;Di Ciano et al, 2001;Parkinson et al, 2002;Wakabayashi et al, 2004).…”