Expression profiling by high throughput sequencing
Summary
Stroke causes death of brain tissue leading to long-term deficits. Behavioral evidence from neurorehabilitative therapies suggest learning-induced neuroplasticity can lead to beneficial outcomes. However, molecular and cellular mechanisms that link learning and stroke recovery are unknown. We show that in mouse models of stroke, with enhanced recovery of function from genetic perturbations of learning and memory genes, express activity-dependent transcriptional programs that are normally active during formation or storage of new memories. The expression of neuronal activity-dependent genes are predictive of recovery and occupy a molecular latent space unique to motor recovery. With motor recovery, networks of activity-dependent genes are co-expressed with their transcription factor targets forming gene regulatory networks that support activity-dependent transcription, that are normally diminished after stroke. Neuronal activity-dependent changes at the circuit level are influenced by interactions with microglia. At the molecular level, we show that enrichment of activity-dependent programs in neurons lead to transcriptional changes in microglia where they differentially interact to support intercellular signaling pathways for axon guidance, growth and synaptogenesis. Together, these studies identify activity-dependent transcriptional programs as a fundamental mechanism for neural repair post-stroke.
Overall design
Cortical neurons and microglia were FAC-sorted at different time points after stroke, where some cohorts of animals received treatments with either neuronal CREB over expression or neuronal CCR5 knockdown as a means to induce recovery of motor function. Each condition has replicates of 3-5 samples where each sample is produced from one animal per condition.