Neuronal activity-dependent gene expression is stimulus-specific and changes with neuronal maturation

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Neuronal activity-dependent gene expression is crucial for brain function.
• Previous studies often used early-stage neuronal cultures (7-10 DIV) with various stimulation protocols.
• The impact of neuronal maturation and specific stimuli (KCl, Bicuculline, TTX-withdrawal) on gene expression remains under-investigated.

Purpose of the Study:

• To investigate how neuronal maturation (7 DIV vs. 21 DIV) affects activity-induced transcription.
• To compare the transcriptional responses to different stimulation protocols (KCl, Bicuculline, TTX-withdrawal) in mature neurons.
• To elucidate the influence of distinct firing patterns on gene expression profiles.

Main Methods:

• Primary neuronal cultures at 7 and 21 days in vitro (DIV) were used.
• Neurons were stimulated with potassium chloride (KCl) and bicuculline (Bic).
• Transcriptional changes in mature neurons (21 DIV) were analyzed using RNA-Sequencing (RNA-Seq) after KCl, Bic, and TTX-withdrawal (TTXw) treatments.

Main Results:

• Neuronal developmental stage profoundly impacts neuronal firing and gene expression.
• KCl and Bicuculline stimulation yielded markedly different transcriptional outcomes, challenging prior assumptions of equivalence.
• Distinct stimuli (KCl, Bic, TTXw) in mature neurons induced specific transcriptional profiles with unique temporal dynamics and gene group activation.

Conclusions:

• Neuronal maturation and specific activation protocols are critical factors in activity-induced gene expression studies.
• Different firing patterns generated by various stimuli lead to distinct gene expression profiles.
• Findings provide insights into transcription-dependent plasticity mechanisms and highlight the need for careful experimental design.