Nociceptive Pain

When our bodies become damaged we experience `nociceptive` pain. This is however based on an individuals experience and can be influenced psychogenically (expectancy or emotionally). If the said individual is distracted or expecting relief from pain, the body can activate a kind of override mechanism. This originates in various areas of the brain particularly at ones that control emotion and attention.

When the brain reacts to pain psychogenically, it causes the descending neuron to become `excited` and send electrical impulses (measured in volts) towards the descending axon terminal in the Spinal Dorsal Horn. These impulses are known as `action potentials` and cause the descending axon terminal to excite the s cell. The s cell then releases a type of neurotransmitter (Enkephalin) into the inhibitory synapse, between the s cell, the nociceptive neuron and the transmission cell. Two things occur here: Enkephalin attaches to receptors on the presynaptic neurons membrane, inhibiting the release of glutamate. Enkephalin attaches to receptors on the postsynaptic neurons membrane, blocking the attachment of glutamate. Depending on the amount of Enkephalin released, any action potentials travelling from a noxious stimulus through the axon of the nociceptive neuron have a reduced to non-existent ability to excite the transmission cell (using glutamate). With no further or very few action potentials travelling up the transmission cell to the pain matrix of the brain, this can either reduce pain or end pain and this is what `closing the gate` is in gate theory.