GSE162417
Optogenetic Stimulation of Prelimbic Pyramidal Neurons Maintains Fear Memories and Modulates Amygdala Pyramidal Neuron Transcriptome
The suppression of fear memory in the absence of danger (fear extinction) requires coordinated neural activity within the amygdala and medial prefrontal (prelimbic and infralimbic) cortex. Any behavior has a transcriptomic signature that is modified by environmental experiences, and specific genes are involved in functional plasticity and synaptic wiring during fear memory and extinction. In the present study, we investigated the effects of optogenetic manipulations of prelimbic pyramidal neurons on amygdala gene expression to analyze the specific transcriptional pathways involved in fear extinction. To this aim, transgenic mice (Thy1-COP4) having cortical and amygdala pyramidal neurons optogenetically excitable were (or not) fear-conditioned. During the extinction phase, the mice received optogenetic (or sham) stimulations to maintain the activation of the prelimbic pyramidal neurons and impair fear extinction. At the end of behavioral testing, electrophysiological (Excitatory Post-Synaptic Currents) and morphological (spinogenesis) correlates were evaluated in the pyramidal neurons of prelimbic cortex. Furthermore, transcriptomic cell-specific RNA-analyses (differential gene expression profiling and functional enrichment analyses) were performed in amygdala pyramidal neurons. Results demonstrate that pyramidal neurons of prelimbic cortex are involved in modulation of the fear responses during extinction phase and their optogenetic stimulation in fear-conditioned mice results in strong modifications of the amygdala transcriptome. Understanding the transcriptomic architecture of fear extinction may facilitate the comprehension of fear-related disorders. Overall design: RNA extracted by amygdala pyramidal neurons of 14 B6.Cg-Tg(Thy1-COP4/EYFP)18Gfng/J (Thy1-COP4) (Jackson Laboratories, Maine, USA) mice