Stimulation protocols, each involving massed training and the corresponding spaced training using three, six, and nine pulses
with a constant ISI, denoted by i, and unit amplitude. (A) SPDC protocol: Duration of spaced pulses (δ) is fixed, with corresponding massed pulse duration npulses × δ for different npulses. (B) DC protocol: Massed pulse duration (Δ) was equally divided into three, six, and nine spaced pulses. In both protocols, the
response was calculated at time 
relative to the final stimulation pulse ending at time ε, and at a fixed tf. (C) Quantification of response: Response to stimulation was quantified using concentrations of the response element (denoted
as 
and 
), peak response concentrations (
and 
), and cumulative activity (
and 
), all sets corresponding to the two measurement times, 
and tf, respectively.
