The input shapes the output: commonly used neuronal activation protocols induce different transcriptional responses

LUKIN, JERONIMO; CHERNOMORETZ, ARIEL; REFOJO, DAMIÁN; BECKEL, MAXIMILIANO; KADENER, SEBASTIAN; GIUSTI, SEBASTIAN; MARIN-BURGIN, ANTONIA

virtual

Congreso; XXXV Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2020

Sociedad Argentina de Investigación en Neurociencias (SAN)

Activity-driven gene expression is necessary to implement synaptic plasticity mechanisms required to encode, store and retrieve long-lasting information. The precise activity-transcription coupling has been extensively studied in neuronal cultures but the underlying mechanisms are not fully clear yet. Multiple studies approached this question using 3 stimulation protocols: KCl, Bicuculline (Bic) and TTX withdrawal (TTXw). KCl drastically changes membrane potential in a sustained manner, Bic induces synaptic bursting and TTXw, elicits a rebound-based neuronal activity response after a long- lasting silencing. Despite these protocols have different mechanisms of action, they have been indistinguishably employed in the field. Thus, we wonder whether they can be considered as truly equivalent protocols.To address this question, we used activity-driven gene expression as a proxy: we stimulated neuronal cultures with KCl, Bic and TTXw and globally examined mRNA expression at different time- points by RNA-seq. PCA analysis showed strong divergencies, with TTXw being clearly different compared to KCl and Bic. Gene set enrichment analysis and clustering approaches indicated that each protocol induced specific modules of genes with particular temporal dynamics and related to different biological processes.These results indicate that KCl, Bic and TTXw are not functionally equivalent what might help explain multiple discrepancies found throughout the extensive literature of the field.