Expression of<unk>  is an indirect marker of neuronal activity because<unk>  is often expressed when neurons fire action potentials. Upregulation of<unk>  mRNA in a neuron indicates recent activity. The<unk>  promoter has also been utilised for drug abuse research. Scientists use this promoter to turn on transgenes in rats, allowing them to manipulate specific neuronal ensembles to assess their role in drug-related memories and behavior. This neuronal control can be replicated with optogenetics or DREADDs
C-Fos
Orf 
Bcl-2
BIM-1
AP-7 
HER2/neu
COVAX-19
Mad2