<span>After strenuous exercise, a muscle cell would contain decreased amounts of ATP</span>
<span>The probability of an action potential being propagated from neuron to neuron is increased when the postsynaptic neuron's signal is in an excitatory state. During this state, the action potential of a presynaptic neuron increases the probability of transmission of a signal to the postsynaptic neuron.</span>
Here is what I found, its quite interesting, I hope it helps..
https://www.fbi.gov/services/laboratory/biometric-analysis/codis/codis-and-ndis-fact-sheet
