Homer 1a and mGluR5 phosphorylation in reward-sensitive metaplasticity: A hypothesis of neuronal selection and bidirectional synaptic plasticity

Research output: Contribution to journalReview article


Drug addiction and reward learning both involve mechanisms in which reinforcing neuromodulators participate in changing synaptic strength. For example, dopamine receptor activation modulates corticostriatal plasticity through a mechanism involving the induction of the immediate early gene Homer 1a, the phosphorylation of metabotropic glutamate receptor 5 (mGluR5)′s Homer ligand, and the enhancement of an NMDA receptor-dependent current. Inspired by hypotheses that Homer 1a functions selectively in recently-active synapses, we propose that Homer 1a is recruited by a synaptic tag to functionally discriminate between synapses that predict reward and those that do not. The involvement of Homer 1a in this mechanism further suggests that decaminutes-old firing patterns can define which synapses encode new information. This article is part of a Special Issue entitled SI:Addiction circuits.

Original languageEnglish (US)
Pages (from-to)17-28
Number of pages12
JournalBrain research
StatePublished - Dec 2 2015



  • Addiction
  • Dopamine
  • Eligibility trace
  • Homer
  • Immediate early gene
  • NMDA receptor
  • Neuronal selection
  • PIN1
  • Proto weight
  • Provisional weight
  • Reinforcement learning
  • Reward learning
  • Synaptic plasticity
  • Synaptic tag
  • mGluR5

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

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