CNR - Institute of Neuroscience CNR
Institute of Neuroscience
 

Project

Neurobiological basis of motivated behavior

Experimental manipulation of dopamine (DA) transmission by lesions and drugs indicates a role in the acquisition and expression of behavior motivated by conventional and drug reinforcers. This role is related to modulation of ionotropic transmission, mainly in the ventral stiatum (nucleus accumbens/olfactory tubercle), in components of the so-called extended amygdala (central amygdala and bed nucleus of stria terminalis) and in the medial prefrontal cortex.

Role of DA in motivated behavior

DA release in the nucleus accumbens (NAc) elicits an appetitive state (euphoria), facilitates memory consolidation in Pavlovian learning, promotes approach behavior towards novel cues and contexts and mediates the energizing action of conditioned stimuli on instrumental behavior. These functions can be related to differential stimulation of DA transmission by conditioned and unconditioned motivational stimuli in different DA terminal areas.

Nucleus accumbens shell and core DA

In the NAc shell DA responsiveness follows Pavlovian rules, being related to appetitive valence, novelty and unpredictability of the stimulus. In contrast, NAc core and medial prefrontal cortex DA responds to both conditioned and unconditioned stimuli in relation to their generic motivational relevance. These properties conform to a role of DA in incentive arousal. This term describes the state induced by DA released in response to motivational stimuli and its widespread influence on behavior: euphoria and elevated mood, facilitation of the acquisition of incentive properties by otherwise neutral stimuli and contexts through Pavlovian association (incentive learning), facilitation of instrumental and approach behavior by conditioned incentives. Addictive drugs share the ability to stimulate DA transmission in the ventral striatum and in particular in the NAc shell. According to the incentive-learning hypothesis drug addiction would be the result of the excessive incentive properties acquired by drug-conditioned stimuli following maladaptive stimulation of DA transmission in the NAc shell.

The main focus of this research project is to elucidate the different roles played by DA in the shell and core compartment of NAc in the rewarding and motivational properties of conventional and drug reinforcers by the use of in vivo brain microdialysis applied to different behavioral experimental paradigms.

Publications

  • Fenu S, Rivas E, Di Chiara G (2009) Differential involvement of dopamine D1 receptors in morphine- and lithium-conditioned saccharin avoidance. Physiol. Behav. 96:73-7.
  • De Luca MA, Bassareo V, Bauer A, Di Chiara G (2007) Caffeine and accumbens shell dopamine. J. Neurochem. 103:157-63.
  • Lecca D, Valentini V, Cacciapaglia F, Acquas E, Di Chiara G (2007) Reciprocal effects of response contingent and noncontingent intravenous heroin on in vivo nucleus accumbens shell versus core dopamine in the rat: a repeated sampling microdialysis study. Psychopharmacology (Berl.) 194:103-16.
  • Di Chiara G, Bassareo V (2007) Reward system and addiction: what dopamine does and doesn't do. Curr Opin Pharmacol 7:69-76.
  • Bassareo V, De Luca MA, Di Chiara G (2007) Differential impact of pavlovian drug conditioned stimuli on in vivo dopamine transmission in the rat accumbens shell and core and in the prefrontal cortex. Psychopharmacology (Berl.) 191:689-703.
  • Fenu S, Spina L, Rivas E, Longoni R, Di Chiara G (2006) Morphine-conditioned single-trial place preference: role of nucleus accumbens shell dopamine receptors in acquisition, but not expression. Psychopharmacology (Berl.) 187:143-53.
  • Spina L, Fenu S, Longoni R, Rivas E, Di Chiara G (2006) Nicotine-conditioned single-trial place preference: selective role of nucleus accumbens shell dopamine D1 receptors in acquisition. Psychopharmacology (Berl.) 184:447-55.
  • Di Chiara G, Bassareo V, Fenu S, De Luca MA, Spina L, Cadoni C, Acquas E, Carboni E, Valentini V, Lecca D (2004) Dopamine and drug addiction: the nucleus accumbens shell connection. Neuropharmacology 47 Suppl 1:227-41.
  • Bassareo V, De Luca MA, Di Chiara G (2002) Differential Expression of Motivational Stimulus Properties by Dopamine in Nucleus Accumbens Shell versus Core and Prefrontal Cortex. J. Neurosci. 22:4709-19.
  • Fenu S, Bassareo V, Di Chiara G (2001) A role for dopamine D1 receptors of the nucleus accumbens shell in conditioned taste aversion learning. J. Neurosci. 21:6897-904.

Collaborations

  • Prof. Dreyer Jean Luc, University of Fribourg, Division of Biochemistry, Dept of Medicine, Fribourg Switzerland.
  • Prof. Kessler David, University of California, School of Medicine, San Francisco, USA.
  • Dr. Franco Borsini, Sigma Tau S.p.A. Pomezia, Italy.

 

no PI photo

Gaetano Di Chiara

Contact information

email  E-mail

email  +39 0706758666

Participating staff

Valentina Bassareo

Cristina Cadoni

Ezio Carboni

Maria Antonietta De Luca

Elio Acquas

Federico Ibba

Daniele Lecca

Augusta Pisanu

Liliana Spina

Valentina Valentini