The resting potential of the neuron: the electrostatics gradient and the concentration gradient. The action potential and how it travels down the axon. The electrostatic gradient is connected to the concentration gradient because the concentration is made of ions, which are electrically charged particles. The neuron is negative at resting, the sodium particles are positive. The neuron can open receptors to allow the positive charge to flow in. As the charge becomes more positive, more channels open up and the positive particles cascade through and then out of the neuron. The all or nothing principles& its implication for neural firing (i. e. greater amplitude=more frequency) Firing over entire brain system depends on multiple neurons activating a whole network, and each neuron depends on a whole array of inputs sufficient to the trigger its own action potential. Inhibition and excitation- signal strength, inhibition or excitation, some kind of summation integration. Patterns of activity iff patterns of connectivity.