Vulcan neuro-pressure was a mental and physical technique for relaxing the mind and muscles. It involved stimulating neural nodes and pressure points in a Vulcan or Human body. A highly specialized discipline, neuro-pressure involved numerous techniques, was extremely difficult to learn, and took years to master. Also being very personal, it required a great deal of physical contact.
One of the techniques involved in neuro-pressure was a specific breathing method. Other neuro-pressure techniques included the surah'tahn and the Khavorta posture (the latter of which was difficult because of the necessity for not only a certain breathing method but also a relaxed jaw). An application of neuro-pressure for combat was the so-called Vulcan nerve pinch.
Neuro-pressure could result in paralysis, but the risk of that (at least when neuro-pressure was done by a skilled practitioner) was minimal. Neuro-pressure conducted by a novice could also result in the recipient experiencing headaches or even receiving nerve damage. (ENT: "The Xindi", "Anomaly (ENT)", "Extinction", "Rajiin", "Harbinger", "E²")
Aboard Enterprise NX-01, T'Pol – who was skilled in neuro-pressure – began administering it to Commander Tucker after his sister died, as he was having trouble sleeping. (ENT: "The Xindi") As far as T'Pol was aware, Vulcan neuro-pressure was never tried on a Human prior to her sessions with Tucker. (ENT: "Extinction") Those sessions typically took an hour or thereabouts. (ENT: "Anomaly (ENT)") Following his first neuro-pressure session with her, Tucker slept very well. (ENT: "Extinction")
In a conversation in Enterprise's mess hall after Tucker had his first neuro-pressure session, he notified Lieutenant Malcolm Reed that T'Pol had been showing him "how to stimulate [his] neural nodes" in an attempt to help him sleep, though Tucker also warned that the neuro-pressure wasn't what Reed was thinking it was. In reply, Reed stated, "I wasn't thinking anything." T'Pol likewise informed Dr. Phlox that the first neuro-pressure treatment she administered to Tucker had gone well. Upon discovering Tucker had only had an hour's sleep during the previous night, Phlox was surprised the neuro-pressure apparently wasn't working and began to suspect it was because Tucker felt uncomfortable with the degree of intimacy it required. However, Tucker dismissed that notion, saying he was too busy to participate in a neuro-pressure session with T'Pol once a night. Since the only alternative treatment for his insomnia was Aldebaran mud leeches, he immediately rethought his decision by indeed agreeing to have one of T'Pol's neuro-pressure sessions nightly. (ENT: "Anomaly (ENT)")
After canceling two sessions with her due to being extremely busy, Tucker soon returned to T'Pol's quarters for another neuro-pressure session late one night, additionally bringing her some Georgia peaches as a gift. At T'Pol's insistence, her next neuro-pressure session with him was planned to include stimulation of the neural nodes on his feet, as there were many neural nodes in the soles of the feet (at least in a Human body). Though he was initially shocked by the suggestion due to being ticklish, he eventually agreed to the plan. T'Pol began the session by stimulating the neural nodes on Tucker's back. He at first felt her touch was too cold but then began to enjoy the session, which was thereafter abruptly ended when T'Pol was called to the command center by Captain Archer. (ENT: "Extinction")
When, in December of 2153, Tucker revealed to T'Pol that he had begun thinking she had been avoiding him, she replied, "Three neuro-pressure sessions a week is hardly avoiding you." (ENT: "Proving Ground")
Later that month, Tucker began conducting sessions in which he administered neuro-pressure to MACO Corporal Amanda Cole, without T'Pol's supervision and awareness. Cole was a willing participant in these sessions and Tucker taught her the correct breathing technique for neuro-pressure.
About a week after they began their neuro-pressure sessions with each other, Tucker and Cole had one of the sessions in which, although Cole found Tucker applying neuro-pressure to her right foot initially felt okay, she jerked that foot away from him, moments later. Tucker briefly considered that he might be doing the neuro-pressure incorrectly, though Cole suggested trying another posture, so Tucker instead tried applying neuro-pressure to Cole's back, which felt "great" to Cole. She was disappointed that neuro-pressure couldn't be included in a training routine which Major J. Hayes regularly put the MACOs through. Though Tucker suggested proposing the idea to Hayes, Cole was extremely doubtful that he would accept neuro-pressure into the MACOs' regimen. By the time Tucker was finished applying neuro-pressure to Cole's back, she felt extremely refreshed, as if she had just awoken after twelve hours sleep, which lead Tucker to suspect he had been doing the neuro-pressure correctly after all.
When Cole visited Phlox with complaints of recurring headaches and a mention of the neuro-pressure she had been receiving from Tucker, Phlox began to suspect the neuro-pressure was to blame for Cole's headache, thinking Tucker might have misapplied one of the techniques, as he had only been receiving neuro-pressure for the past couple of months. Phlox therefore cautioned Cole to be cautious about accepting any more neuro-pressure from Tucker. When Phlox told T'Pol about his theory that the neuro-pressure Cole had been receiving might be responsible for her headaches, T'Pol concurred that this was indeed possible. At Phlox's request, T'Pol spoke to Tucker about his treatments with Cole, attempting to discourage him from doing so.
T'Pol also arranged a neuro-pressure session with Cole herself, since Phlox had suggested to T'Pol she could thereby attempt to undo some of the inexperienced work on Cole which Tucker had done. Cole appreciated T'Pol taking some time to do so but winced at least once during the session, in response to T'Pol pressing too hard on her back. Promising to try not to press that hard again, T'Pol resumed the session with Cole.
Shortly afterwards, Lieutenant Reed asked Tucker, in the mess hall, if he could confirm rumors that T'Pol was now giving Cole neuro-pressure and that it was "damage control" from Tucker's "tender touch". Tucker essentially did confirm these details, though tried to downplay them. Reed was right to be suspicious of there being more to Tucker's relationships with both Cole and T'Pol than just neuro-pressure. However, Tucker attempted to deny the intimacy of that practice. In reply, Reed tried to make light of Tucker's answer by starting to humorously imply he would like Tucker to conduct neuro-pressure on him, though Tucker cut him off mid-sentence.
At night, T'Pol and Tucker had another of their neuro-pressure sessions. While lying on his back, Tucker admitted he had been eagerly anticipating the session throughout the day. After Tucker changed position, he wondered why the few neuro-pressure sessions he had participated in with Cole had been such a big deal, which led him and T'Pol to discuss their relationship, a conversation which preceded sexual interaction (for the first time) between them. Though they later agreed to forget about their sexual encounter, they meanwhile arranged to continue their neuro-pressure sessions. (ENT: "Harbinger")
After T'Pol was confined to quarters in January 2154, Tucker cited neuro-pressure treatment, purportedly on orders from Phlox, as an excuse for Corporal D. Chang to let him see her. Chang initially fell for Tucker's ruse, allowing Tucker into T'Pol's quarters. However, when Tucker returned while feigning nerve damage from the previous session, Chang refused to let him see T'Pol but was so distracted himself that Lieutenant Reed and Doctor Phlox quickly crept up on him, seized a particle rifle he was carrying, and rendered him unconscious with a hypospray, prior to them and Tucker finally releasing T'Pol. (ENT: "Hatchery")
Weeks after Tucker and T'Pol had their last neuro-pressure session, Tucker visited T'Pol's quarters under the pretense that he had come for another session. He claimed that he was again suffering from insomnia and that he believed the neuro-pressure would be good to relieve stress they had been under. T'Pol, however, wanted to stop the treatment, saying her reluctance to continue it was because Tucker had become so skilled at neuro-pressure that she felt she had taught him all she could. Tucker initially questioned her explanation but then decided to admit he had actually come because he was concerned about her. (ENT: "E²")
Later in 2154, Tucker became extremely worried about T'Pol serving as a test subject for a makeshift telepresence unit but Phlox advised him not to interfere in the experiments. Trying to dismiss this advice by exemplifying poorly judged suggestions Phlox had made, Tucker cited Phlox having recommended the neuro-pressure between him and T'Pol. Phlox reminded Tucker it had been prescribed as an effort to remedy his trouble sleeping. (ENT: "The Aenar")
In a holographic program set in 2161, a holographic version of Phlox casually informed Chef – once portrayed by William T. Riker, in 2370 – about the neuro-pressure treatment which Tucker had reluctantly received. (ENT: "These Are the Voyages...")
As scripted for "The Xindi", the displays of Vulcan neuro-pressure performed in that episode would have been done while the participants were kneeling on the floor rather than, as they are in the episode, sitting on a bed.
In the original script for ENT: "Twilight", Archer suggested to T'Pol that neuro-pressure might be helpful for his pet beagle Porthos, as the dog had been experiencing stress over being in the Delphic Expanse, and because Archer had heard neuro-pressure had been helpful for Tucker. ("Twilight" audio commentary, ENT Season 3 Blu-ray special features) However, this conversation was written out of the episode by the time the final draft of the script was issued.
Manny Coto struggled with the writing of a neuro-pressure scene in "Similitude". "I was a little bit concerned about having to write one of these massage scenes," he explained. "They had been going on throughout the [third] season [...] They were supposed to be sensual and they were tough to write because, I think, before this episode, they had done four or five, and it was tough to come with a new idea [...] It was a little bit of a challenge coming up with a new position, so to speak." Despite this difficulty, Coto managed to conceive of a foot-related massage technique being incorporated into the Vulcan neuro-pressure. ("Similitude" audio commentary, ENT Season 3 DVD)
The final draft script of "Harbinger" pointed out that a particular posture for neuro-pressure is shown in both that episode and "Similitude", described in the script as "lying side-by-side, but in opposite directions." Also, an ultimately excised line of dialogue from the same script would have established that the proper breathing technique for neuro-pressure was (in T'Pol's words) to, "at the end of every third breath, hold for five seconds."