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Lesion of medial prefrontal dopamine terminals abolishes habituation of accumbens shell dopamine responsiveness to taste stimuli
Author(s) -
Bimpisidis Zisis,
Luca Maria Antonietta,
Pisanu Augusta,
Di Chiara Gaetano
Publication year - 2013
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12068
Subject(s) - microdialysis , nucleus accumbens , habituation , dopamine , prefrontal cortex , lesion , taste , chemistry , endocrinology , medicine , sensitization , neuroscience , psychology , pathology , cognition
Taste stimuli increase extracellular dopamine ( DA ) in the nucleus accumbens ( NA c) and in the medial prefrontal cortex (m PFC ). This effect shows single‐trial habituation in NA c shell but not in core or in m PFC . Morphine sensitization abolishes habituation of DA responsiveness in NA c shell but induces it in m PFC . These observations support the hypothesis of an inhibitory influence of m PFC DA on NA c DA . To test this hypothesis, we used in vivo microdialysis to investigate the effect of m PFC 6‐hydroxy‐dopamine (6‐ OHDA ) lesions on the NA c DA responsiveness to taste stimuli. 6‐ OHDA was infused bilaterally in the m PFC of rats implanted with guide cannulae. After 1 week, rats were implanted with an intraoral catheter, microdialysis probes were inserted into the guide cannulae, and dialysate DA was monitored in NA c shell/core after intraoral chocolate. 6‐ OHDA infusion reduced tissue DA in the m PFC by 75%. Tyrosine hydroxylase immunohistochemistry showed that lesions were confined to the m PFC . m PFC 6‐ OHDA lesion did not affect the NA c shell DA responsiveness to chocolate in naive rats but abolished habituation in rats pre‐exposed to the taste. In the NA c core, mPFC lesion potentiated, delayed and prolonged the stimulatory DA response to taste but failed to affect DA in pre‐exposed rats. Behavioural taste reactions and motor activity were not affected. The results indicate a top‐down control of NA c DA by mPFC and a reciprocal relationship between DA transmission in these two areas. Moreover, habituation of DA responsiveness in the NA c shell is dependent upon an intact DA input to the mPFC .