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Spatial exploration induces ARC , a plasticity‐related immediate‐early gene, only in calcium/calmodulin‐dependent protein kinase II‐positive principal excitatory and inhibitory neurons of the rat forebrain
Author(s) -
Vazdarjanova Almira,
RamirezAmaya Victor,
Insel Nathan,
Plummer Thane K.,
Rosi Susanna,
Chowdhury Shoaib,
Mikhael Dalia,
Worley Paul F.,
Guzowski John F.,
Barnes Carol A.
Publication year - 2006
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.21003
Subject(s) - arc (geometry) , neuroscience , neocortex , biology , striatum , long term potentiation , hippocampal formation , inhibitory postsynaptic potential , excitatory postsynaptic potential , receptor , genetics , geometry , mathematics , dopamine
Abstract Active behavior, such as exploring a novel environment, induces the expression of the immediate‐early gene Arc ( a ctivity‐ r egulated c ytoskeletal associated protein, or Arg 3.1) in many brain regions, including the hippocampus, neocortex, and striatum. Arc messenger ribonucleic acid and protein are localized in activated dendrites, and Arc protein is required for the maintenance of long‐term potentiation and memory consolidation. Although previous evidence suggests that Arc is expressed in neurons, there is no direct demonstration that only neurons can express Arc. Furthermore, there is no characterization of the main neuronal types that express Arc. The data reported here show that behavior‐ or seizure‐induced Arc expression in the hippocampus, primary somatosensory cortex, and dorsal striatum of rats colocalizes only with neuronal (NeuN‐positive) and not with glial (GFAP‐positive) cells. Furthermore, Arc was found exclusively in non‐GABAergic α‐ CaMKII ‐positive hippocampal and neocortical neurons of rats that had explored a novel environment. Some GAD65/67 ‐positive neurons in these regions were observed to express Arc , but only after a very strong stimulus (electroconvulsive seizure). In the dorsal striatum, spatial exploration induced Arc only in GABA ergic and α‐ CaMKII ‐positive neurons. Combined, these results show that although a very strong stimulus (seizure) can induce Arc in a variety of neurons, behavior induces Arc in the CaMKII ‐positive principal neurons of the hippocampus, neocortex, and dorsal striatum. These results, coupled with recent in vitro findings of interactions between Arc and CaMKII, are consistent with the hypothesis that Arc and CaMKII act as plasticity partners to promote functional and/or structural synaptic modifications that accompany learning. J. Comp. Neurol. 498:317–329, 2006. © 2006 Wiley‐Liss, Inc.