Data from the microdialysis sessions shown in Figure 1 were replotted to allow for direct comparison of the effects produced by the different stimuli within each striatal sector (in main Figure 1 comparisons were performed between sectors). Representative cases for ventral (top) and dorsal (bottom) striatum are shown along with schematic representation of the location of microdialysis probes (VS in red and DS in blue). Histological analyses of brain tissue obtained from the animals that performed the experiments described above. Brain microdialysates were collected concomitantly to behavioural performance. Lick detection triggers an infusion pump that delivers either glucose or more sucralose into the stomach. Mice are placed in an operant box where a spout containing the artificial sweetener sucralose is connected to a contact lickometer. Afferent connections of the parvocellular reticular formation: a horseradish peroxidase study in the rat. Distinct dopamine neurons mediate reward signals for short- and long-term memories. Layered reward signalling through octopamine and dopamine in Drosophila. Taste-independent detection of the caloric content of sugar in Drosophila. Chemogenetic tools to interrogate brain functions. Role of the basal ganglia in the initiation of saccadic eye movements. Relations between movement and single cell discharge in the substantia nigra of the behaving monkey. Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats. Concurrent activation of striatal direct and indirect pathways during action initiation. Cell type-specific loss of BDNF signaling mimics optogenetic control of cocaine reward. Distinct roles for direct and indirect pathway striatal neurons in reinforcement. A high-throughput screening procedure for identifying mice with aberrant taste and oromotor function. Sexually dimorphic neurons in the ventromedial hypothalamus govern mating in both sexes and aggression in males. Membrane properties of striatal direct and indirect pathway neurons in mouse and rat slices and their modulation by dopamine. Dopamine differentially modulates the excitability of striatal neurons of the direct and indirect pathways in lamprey. Taste pathways that mediate accumbens dopamine release by sapid sucrose. Nucleus accumbens neurons are innately tuned for rewarding and aversive taste stimuli, encode their predictors, and are linked to motor output. Nutrient selection in the absence of taste receptor signaling. Dopamine signaling in the dorsal striatum is essential for motivated behaviors: lessons from dopamine-deficient mice.

Dopaminergic mechanisms in actions and habits. Wickens, J.R., Horvitz, J.C., Costa, R.M. Reward-guided learning beyond dopamine in the nucleus accumbens: the integrative functions of cortico-basal ganglia networks. The evolutionary origin of the vertebrate basal ganglia and its role in action selection. Plastic corticostriatal circuits for action learning: what's dopamine got to do with it? Ann. Modulation of striatal projection systems by dopamine. Neural systems of reinforcement for drug addiction: from actions to habits to compulsion. Independent circuits in the basal ganglia for the evaluation and selection of actions. Stephenson-Jones, M., Kardamakis, A.A., Robertson, B. Food reward in the absence of taste receptor signaling. Post-ingestive positive controls of ingestive behavior. Our data indicate that sugar recruits a distributed dopamine-excitable striatal circuitry that acts to prioritize energy-seeking over taste quality. Conversely, optogenetic stimulation of dopamine-excitable cells in dorsal, but not ventral, striatum substituted for sugar in its ability to drive the ingestion of unpalatable solutions. Consistently, cell-specific ablation of dopamine-excitable cells in dorsal, but not ventral, striatum inhibited sugar's ability to drive the ingestion of unpalatable solutions. During sugar intake, suppressing hedonic value inhibited dopamine release in ventral, but not dorsal, striatum, whereas suppressing nutritional value inhibited dopamine release in dorsal, but not ventral, striatum. We found in mice that separate basal ganglia circuitries mediated the hedonic and nutritional actions of sugar. It is, however, unknown whether sweetness and nutritional signals engage segregated brain networks to motivate ingestion. Sugar exerts its potent reinforcing effects via both gustatory and post-ingestive pathways.

Hedonic