Nature

The ability to associate temporally segregated information and assign positive or negative valence to environmental cues is paramount for survival. Studies have shown that different basolateral amygdala (BLA) projections are potentiated following reward or punishment learning1–7. However, we do not yet understand how valence specific information is routed to the BLA neurons with the appropriate downstream projections. Nor do we understand how to reconcile the subsecond timescales of synaptic plasticity8–11 with the longer timescales separating the predictive cues from their outcomes. Here, we demonstrate that neurotensin (NT) neurons in the paraventricular nucleus of the thalamus (PVT) projecting to the BLA (PVT-BLA:NT) mediate valence assignment by exerting concentration-dependent modulation in BLA during associative learning. We found that optogenetic activation of the PVT-BLA:NT projection promotes reward learning, while PVT-BLA projection-specific Nt gene knockout augments punishment learning. Using genetically encoded calcium and NT sensors, we further revealed that both calcium dynamics within the PVT-BLA:NT projection and NT concentrations in the BLA are enhanced after reward learning and reduced after punishment learning. Finally, we showed that CRISPR-mediated knockout of the Nt gene in the PVT-BLA pathway blunts BLA neural dynamics and attenuates the preference to active behavioral strategies to reward and punishment predictive cues. Taken together, we have identified NT as a neuropeptide that signals valence in the BLA, and showed that NT is a critical neuromodulator that orchestrates positive and negative valence assignment in amygdala neurons by extending valence-specific plasticity to behaviorally-relevant timescales

Enhancer RNAs are necessary and sufficient for activity-dependent neuronal gene transcription

Enhancer elements in DNA regulate gene expression programs important for neuronal fate and function, and are increasingly implicated in brain disease states. Enhancers undergo bidirectional transcription to generate non-coding enhancer RNAs (eRNAs), but the function of eRNAs in neuronal systems remains controversial. Here, we performed genome-wide characterization of transcribed enhancers from rat cortical neurons, revealing elevated sequence conservation, enriched localization near genes involved in neuronal or synaptic function, and correlated activity-dependent regulation of putative eRNA-mRNA pairs. Functional validation using a CRISPR-dCas9 fusion system to drive eRNA synthesis from enhancers produced corresponding increases in mRNA at linked genes. Focusing on eRNAs arising from enhancers at the Fos gene locus, we report that eRNA and mRNA correlate on a single-cell level, that CRISPR-targeted eRNA delivery to an enhancer is sufficient for mRNA induction, and that eRNA knockdown decreases mRNA and alters neuronal physiology. These results suggest that eRNAs regulate gene expression and neuronal function