Neurons must reach an action potential before they pass their signal, right? So then, I'm saying they primarily inhibit the transmission of all signals, until the energy has surpassed this potential. And, since the majority of neurons are not transmitting simultaneously, then the majority are blocking energy flow in any one instant of time.
A nerve doesn't 'reach' an action potential. The action potential is the term we use for what happens along the axon. The action potential is an exchange of positive negative ions through channels along the axon that propagates like electricity through a wire. In gray matter (mostly brain and central spinal cord areas) the action potentials travel a bit slower than in the periphery, because in the peripheral nervous system, we have white matter, which is basically gray matter covered in a protective sheath called myelin. The myelin allows the action potential to propagate faster by causing it to jump distances between channels.
Nerves have 'thresholds' which can be reached by the application of enough stimulus to the nerve endings. Be them light touch, pain, temperature, proprioceptive endings, or whatever, they all fire when enough of the right stimulus is applied. When a threshold is reached, an action potential is created (think of it like a gun trigger. If you press very lightly, it won't fire. If you press just hard enough, bang). Neurons are not inhibiting the transmission of signals any more than a trigger is inhibiting a gun from firing... they are simply waiting to propagate a signal when enough stimulus is applied. They aren't blocking anything. You make it sound like they are actively working to stop something. That's absolutely ridiculous.
Considering what happens when a nerve is connected with another nerve... When an action potential reaches the end of the axon (the synapse), it releases a neurotransmitter (chemical) which crosses the tiny space between the axons and attaches to receptors on the next nerve. If enough neurotransmitter is released to reach the 'threshold' of firing, the action potential will continue along the next axon. If not, then it won't continue it. Oftentimes, a lack of specific neurotransmitters in the brain, or lack of, or damaged receptors will lead to all sorts of problems, and it is easy to imagine why... because if an action potential normally releases X amount of neurotransmitter, and that neurotransmitter is lacking or not taken up, the 'normal' result of a continued action potential will be inhibited. This explains why medications effecting neurotransmitters can have dramatic effects on people with conditions such as depression or other psych issues.
At least... that's how it all worked when I went to school 15 years ago lol.