Promoter IV is activated by stimuli like synaptic activity, calcium influx, or action potential firing via transcription factors such as CREB (cAMP response element-binding protein), hence the immediate post epilepsy BDNF levels reflect the degree of seizure-induced neuronal activity, which in this case could serve as a proxy or indicator for epilepsy severity or strength in some cases. This evidence concerns the gene BDNF and epilepsy.