Synaptic activity-regulated gene expression_embryonic day 18

ABSTRACT: Activity-dependent changes in synapses rely on functional changes in resident proteins and on gene expression. We addressed the relationship between synapse activity and the expression of synaptic genes by comparing RNA levels in the neocortex of normal mice versus synaptically silent munc18-1 null mutants, using microarray expression analysis, quantitative PCR and Northern blotting. We hypothesized that genes under control of synaptic activity are differentially expressed between mutants and controls and found that few synaptic signaling genes were differentially expressed. However, all neuropeptide genes with detectable expression on the microarray were differentially expressed, being 3-20 fold higher in control cortex. Genes encoding their receptors and most other synaptic components were not differentially expressed. Differential expression of the neuropeptide genes was confirmed by qPCR analysis. In situ hybridization indicated that the difference in neuropeptide expression was uniform and not due to the loss of specific cells in the mutant. In primary sensory neurons, which do not depend on synaptic activity for their input, the differential expression of neuropeptides was not observed. These data reveal no simple relation between activity of synapses and expression of their resident proteins, but instead identified a unique feature of neuropeptide gene expression, which appears to depend on synaptic activity. Keywords: munc18-1 null mutant mice are characterized by the complete loss of both evoked and spontaneous transmitter release 11 biological replicates of munc18-1 null mutants, hybridized with 11 pooled biological replicates. On six arrays the mutant sample was labeled with cy3 and on the other five with cy5.

ORGANISM(S): Mus musculus

SUBMITTER: Jildau Bouwman 

PROVIDER: E-GEOD-3639 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress