Impact of serotonin 2C receptor null mutation on physiology and behavior associated with nigrostriatal dopamine pathway function

Luna Abdallah, Stephen J. Bonasera, F. Woodward Hopf, Laura O'Dell, Marco Giorgetti, Minke Jongsma, Scott Carra, Massimo Pierucci, Giuseppe Di Giovanni, Ennio Esposito, Loren H. Parsons, Antonello Bonci, Laurence H. Tecott

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


The impact of serotonergic neurotransmission on brain dopaminergic pathways has substantial relevance to many neuropsychiatric disorders. A particularly prominent role has been ascribed to the inhibitory effects of serotonin 2C receptor (5-HT2CR) activation on physiology and behavior mediated by the mesolimbic dopaminergic pathway, particularly in the terminal region of the nucleus accumbens. The influence of this receptor subtype on functions mediated by the nigrostriatal dopaminergic pathway is less clear. Here we report that a null mutation eliminating expression of 5-HT2CRs produces marked alterations in the activity and functional output of this pathway. 5-HT 2CR mutant mice displayed increased activity of substantia nigra pars compacta (SNc) dopaminergic neurons, elevated baseline extracellular dopamine concentrations in the dorsal striatum (DSt), alterations in grooming behavior, and enhanced sensitivity to the stereotypic behavioral effects of D-amphetamine and GBR 12909. These psychostimulant responses occurred in the absence of phenotypic differences in drug-induced extracellular dopamine concentration, suggesting a phenotypic alteration in behavioral responses to released dopamine. This was further suggested by enhanced behavioral responses of mutant mice to the D1 receptor agonist SKF 81297. Differences in DSt D1 or D2 receptor expression were not found, nor were differences in medium spiny neuron firing patterns or intrinsic membrane properties following dopamine stimulation. We conclude that 5-HT2CRs regulate nigrostriatal dopaminergic activity and function both at SNc dopaminergic neurons and at a locus downstream of the DSt.

Original languageEnglish (US)
Pages (from-to)8156-8165
Number of pages10
JournalJournal of Neuroscience
Issue number25
StatePublished - Jun 24 2009
Externally publishedYes

ASJC Scopus subject areas

  • Neuroscience(all)

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