New rules governing synaptic plasticity in core nucleus accumbens medium spiny neurons
UMass Chan Affiliations
Martin LabDepartment of Psychiatry
Brudnick Neuropsychiatric Research Institute
Document Type
Journal ArticlePublication Date
2012-12-01Keywords
spike-timing-dependent plasticitydopamine
calcium stores
endocannabinoids
whole-cell patch-clamp recording
mice
Neuroscience and Neurobiology
Metadata
Show full item recordAbstract
The nucleus accumbens is a forebrain region responsible for drug reward and goal-directed behaviors. It has long been believed that drugs of abuse exert their addictive properties on behavior by altering the strength of synaptic communication over long periods of time. To date, attempts at understanding the relationship between drugs of abuse and synaptic plasticity have relied on the high-frequency long-term potentiation model of T.V. Bliss and T. Lomo [(1973) Journal of Physiology, 232, 331-356]. We examined synaptic plasticity using spike-timing-dependent plasticity, a stimulation paradigm that reflects more closely the in vivo firing patterns of mouse core nucleus accumbens medium spiny neurons and their afferents. In contrast to other brain regions, the same stimulation paradigm evoked bidirectional long-term plasticity. The magnitude of spike-timing-dependent long-term potentiation (tLTP) changed with the delay between action potentials and excitatory post-synaptic potentials, and frequency, whereas that of spike-timing-dependent long-term depression (tLTD) remained unchanged. We showed that tLTP depended on N-methyl-d-aspartate receptors, whereas tLTD relied on action potentials. Importantly, the intracellular calcium signaling pathways mobilised during tLTP and tLTD were different. Thus, calcium-induced calcium release underlies tLTD but not tLTP. Finally, we found that the firing pattern of a subset of medium spiny neurons was strongly inhibited by dopamine receptor agonists. Surprisingly, these neurons were exclusively associated with tLTP but not with tLTD. Taken together, these data point to the existence of two subgroups of medium spiny neurons with distinct properties, each displaying unique abilities to undergo synaptic plasticity.Source
Eur J Neurosci. 2012 Dec;36(12):3615-27. doi: 10.1111/ejn.12002. Epub 2012 Sep 26. Link to article on publisher's site
DOI
10.1111/ejn.12002Permanent Link to this Item
http://hdl.handle.net/20.500.14038/29222PubMed ID
23013293Related Resources
ae974a485f413a2113503eed53cd6c53
10.1111/ejn.12002