Project description:To study the effect of sensory experience on 3D genome structure of the mouse brain, we performed Dip-C on 1,692 single cells from the visual cortex of dark-reared and control mice at different ages throughout the first postnatal month.
Project description:Experience-dependent plasticity of synapses modulates information processing in neural circuits and is essential for cognitive functions. Genomic enhancers are thought to modulate specific sets of synapses by regulating experience-induced transcription to thereby promote neural circuit plasticity. However, this idea remains untested. Thus, here we analyze the cellular and circuit functions of the genomic mechanisms that control the experience-induced transcription of Igf1 (Insulin-like growth factor 1) in disinhibitory VIP interneurons in the adult visual cortex. We find that two sensory-induced enhancers selectively and cooperatively drive sensory-induced Igf1 transcription and that these enhancers homeostatically control the ratio between excitation and inhibition (E/I-ratio) and neural activity in VIP interneurons to thereby restrict visual acuity. Thus, single experience-regulated enhancers are essential for maintaining sensory processing. Since cortical plasticity scales with neural activity in VIP interneurons, this also suggests that experience-induced transcription restricts plasticity in adult neural circuits to preserve the brain’s functional integrity.
Project description:RNA-seq libraries purified from the visual cortices of neurons expressing Emx-, GAD2-, PV-, SST-, or VIP-Cre using the Ribotag allele. Seq libraries are provided from mice raised in standard housing, or housed in the dark for two weeks (dark-housed), or dark-housed and then exposed to light for 1, 3, or 7.5 hours. These seq libraries represent the genetic response of distinct types of cortical interneurons to altered sensory experience. To explore how sensory experience affects gene expression, we examined this process in the visual cortex of adult mice that were housed in standard conditions, in complete darkness (i.e. dark-housed), or dark-housed and then exposed to light for increasing amounts of time. We generated mice that were heterozygous for alleles of either Emx-,Gad2-,Sst-,Vip- or Pv-Cre, and were also heterozygous for the Rpl22-HA (RiboTag) allele, which expresses an HA-tagged ribosomal protein specifically in Cre-expressing neurons. We performed RNA-Seq on RNA isolated from the dark-housed/light-exposed RiboTag-mice; Experiments were done in 3 biological replicates and the visual cortices of 3 mice were pooled per sample at each time-point and for each Cre line.
