Brain Uploading. A Brain Transplant is what happens when a Mad Scientist saws open your skull, removes your brain, and puts it in someone else's body. The details, such as how the transplanted brain interfaces with the new body's nervous system, or how immune rejection is bypassed, tend to be Hand Waved. In Real Life we don't yet have the technology to connect a brain from one person to the spinal cord of another, so at best this would result in an "And I Must Scream" situation.
Often involves a Brain in a Jar at some point.
- Black Jack, being a series that applies Toon Physics to the Medical Drama genre, unsurprisingly has this on occasion.
- In one notable case he gave an artist who had been painting landscapes on an island during an H-bomb test a new body to save him from radiation poisoning. He died anyway from brain cancer but not before completing one last painting.
- Another chapter had a horse's brain put in a man's body to incriminate his owner's killer.
- Ghost in the Shell: Brain Transplants in general are quite common in all GITS works, often from one artificial body to another.
- In the first movie the Major muses that she has no real way of knowing if she even has a brain in her current body.
- In the first episode of Ghost in the Shell: Stand Alone Complex a politician attempted to swap his cyberbrain (a brain enclosed in cybernetics, as common as cell phones) into a waitress gynoid, but a foreign agent instead put his own brain in the politician's body and tried to smuggle the politician's brain out of the country in a suitcase. And they did that all in a restaurant men's room.
- In the Bad Company series by 2000 AD, Kano was taken prisoner by the alien Krool and subjected to a horrifying experiment: Half of his brain was switched with one from a Krool, and he went nearly insane until he met Mad Tommy and they founded Bad Company.
- At the end of the Judge Dredd story "America", the narrator Bennet Beeny witnesses his soulmate America Jara be gunned down by the Judges in a failed terrorist attack on the Statue of Liberty. After America is declared braindead, Beeny has his brain placed in America's body so they can still be together. In a later story, Beeny's new body begins to shut down because it's rejecting the implant.
- Nero: In the classic story Het Rattenkasteel (The Rat Castle) Nero and Detective Van Zwam enter a haunted castle where they are held captive in a dungeon by a Mad Scientist named Dr. Ratsjenko who plans to transplant their brains into those of rats to make rats even smarter. This is also shown in a very macabre Imagine Spot where Nero imagines Ratsjenko cutting open his head and removing the brain. He fails to do so with them, but later he does manage to steal a brain from a university laboratory and put it in a rat, who makes his rat compatriots rise to lead a rebellion against the humans.
- Batman foe the Gorilla Boss was created when mobster George "The Boss" Dyke had his brain transplanted into the body of a gorilla following his execution in the gas chamber. And that's awesome.
- Referenced in Toy Story: while Sid swaps the heads of his sister's doll and a toy pterodactyl, he role-plays like he's a surgeon performing a dangerous "double-bypass brain transplant".
Buzz Lightyear: I don't think that man's ever been to medical school.
- At the end of The Man with Two Brains, Dr Hfuhruhurr, inventor of "cranial screw-top brain surgery", transplants the Brain in a Jar he's been dating into the body of his evil wife.
- This has been a staple of Frankenstein films ever since the 1931 film where the monster received the brain of a violent criminal.
- In The Ghost of Frankenstein Ygor makes Dr. Frankenstein transplant his (Ygor's) brain into the monster's body so they'll be "together forever." Unfortunately they don't have the same blood type so Ygor!Monster is blind, leading to the eyes closed/arms outstretched shuffle that the Monster is Flanderized into having.
- In Abbott and Costello Meet Frankenstein Dracula's plan involves transplanting Costello's brain into the monster.
- In The Brain That Wouldn't Die, a young, mad scientist's girlfriend is beheaded in a car accident. He takes her head back to his lab and keeps it alive with his mad science. Then he searches for another girl who won't be missed, so he can chop her head off and transplant his girlfriend's head on.
- Another film, The Atomic Brain, deals with an old rich woman who seeks to cheat death by having her brain put into the body of a young, healthy woman. The scientist in charge of doing this does a number of tests on dead bodies, which makes them mindless bodies, but doing so with live bodies works wonders. The woman's plan gets derailed due to her initial choice getting mauled, her companion attempting to betray her and the scientist putting her in a cat's body.
- Played for laughs in Young Frankenstein. The monster is supposed to receive the brain of a supersmart person but Igor drops the jar and secretly replaces the brain with one that is marked abnormal. The actual brain transplant is executed in an Offscreen Moment of Awesome. When the monster awakes, of course it turns out to be a moron.
- In Lady Frankenstein, Tanya uses her father's techniques to transplant the brain of her aging lover Charles into the body of the physically perfect but mentally defective stable hand Thomas.
- In H.P. Lovecraft's "The Whisperer in Darkness" the Mi-Go have a tendency to put brains in jars and at least claim they can easily put them back in bodies, not necessarily their original ones.
- In I Will Fear No Evil by Robert A. Heinlein the protagonist has their brain transplanted into a woman's body, it doesn't end well. The event is later mentioned in Time Enough for Love when the possibility of being transferred into an Opposite-Sex Clone is suggested to Lazarus Long, he rejects it.
- In S.I. the protagonist is awakened from cryonic suspension, and suffers severe ethylene glycol poisoning. Fortunately there happened to be a body nearby that lacked a central nervous system.
- In the Discworld novels, this is the ultimate expression of The Igors' philosophy that "What cometh around goeth around". When an Igor dies, his relatives, in addition to sharing his body parts out to whoever needs them, preserve the brain. Eventually, someone will suffer brain death but have a body in good condition, and Igor will be back on someone's feet.
- In the Vorkosigan Saga, Jackson's Whole infamously hosts life extension clinics based on brain transplants into younger clones. The clone's brain is thrown away.
- In Mastermind of Mars, the bulk of Ras Thavas' research involves swapping people's brains. He's even made a business out of it, transplanting the brains of the old and wealthy and/or powerful into younger bodies.
- This is possible, albeit risky, in the Star Wars Expanded Universe. Monks of the B'Omarr order have their brains removed and placed into life-support jars upon reaching enlightenment so they can continue to contemplate the universe forever. Less scrupulous B'Omarr initiates have been known to perform the operation on unwilling patients and even reverse it, implanting brains into other bodies. One of the short stories in Tales from Jabba's Palace implies that Bib Fortuna eventually manages to escape his And I Must Scream fate that way.
- In Fountain Society, a dying scientist's brain is transplanted into a body of a younger man. He eventually rebels against the eponymous society, and destroys their skyscraper by crashing a plane on it while the Big Bad is going through the same operation.
- Soap Within a Show example: In Friends, this is how Joey's character on Days of Our Lives "returns"; the brain of another character gets transplanted into his body. At some point, they start ignoring this and he's just Dr Drake Ramoray again.
- In the Metal Hurlant Chronicles episode "Long Live the King", the winner of the succession tournament has the dying king's brain transplanted into his skull. Presumably his brain was thrown out.
- Happened in a Halloween Episode of Two Guys, a Girl and a Pizza Place, complete with a Mad Scientist character, who switches Pete's brain with Ashley's brain and Berg's brain with Sharon's brain and the only one who can help them is Johnny.
- Out of Jimmy's Head has this happen to the eponymous character, using the brain of a Mr. Alt Disney. However, the retention of the "personality gland" lets Jimmy keep everything that's himself.
- In the 1970s Wonder Woman episode "Gault's Brain", that was the Brain in a Jar's plan, stealing the body of an athletic young man.
- In Kamen Rider Gaim, Ryoma Sengoku at one point transplants his brain into Hakaider's robot body, fights against Gaim and Kikaider, and then transplants his brain back to his own body with no apparent lasting effects.
- Doctor Who:
- In "The Brain of Morbius", Brain in a Jar Morbius intends to have himself transplanted into the Doctor's head.
- In "The Return of Doctor Mysterio", the aliens have their brains transplanted into human hosts by a team of scary surgeons.
- In the The Mr. Potato Head Show episode, "Royal Pain", Dr. Fruitcake rebuilds his creation, Hammy the Ham Monster (who was destroyed by Baloney in the episode, "Aliens Dig Baloney"). To ensure Hammy is much more tame this time around, Dr. Fruitcake has given him the brain of a two-year old child.
Baloney: Now, where did you get the brain of a two-year-old?
Dr. Fruitcake: Trust me, Baloney, you don't want to know.
- Warhammer 40,000. One of the reasons ork paindoks are feared is that they occasionally replace a patient's brain with that of a squig, leaving them comatose for a while while they adapt, then leaving them semifunctional zombies only fit to follow the dok's orders.
- Surgeon Simulator 2013 has a brain surgery mission. In which the entire brain is removed and a new brain is roughly placed in the same place.
- The Sam & Max: The Devil's Playhouse episode They Stole Max's Brain has Sam put the preserved brain of the child-pharaoh Sammun-Mak in Max's emptied head so someone can move it while he looks for the original. Then Sammun-Mak turns traitor once he gets his hands on the Toys of Power, keeping Max's body until his brain is forcefully removed by the Molemen.
- In Narbonic after Dave's first death Dr. Narbon reanimates him, but being a zombie gets boring quickly so she is convinced eventually to clone him a new body and transplant his brain into it.
- In the Dexter's Laboratory episode "Dexter's Assistant," Dexter puts a new brain in Dee Dee's head so she'll be smart enough to help him with his science experiment. Bizarrely, this makes her smarter without changing her memories or identity, and it's never explained where the brain came from.
- I Am Weasel. In "I, Architect," an accident results in both Weasel and Baboon having their skulls cracked open and their brains falling out. Because Weasel's brain is so massive and Baboon's is so tiny, the surgeons place the smaller brain into Weasel's smaller head and the large brain into Baboon's larger head. As a result, Baboon (in Weasel's body) starts making all sorts of chaotic changes to the city, whereas Weasel (in Baboon's body) has to move up from the bottom of society in order to stop Baboon's nonsense.
- Kim Possible. In one episode, Ron dreams that he is on work experience at a hospital, when Kim is brought in from a mission. Ron goes to the ward where Kim is taken where he and the other doctors see that she has caught a disease that has paralyzed her into making do a really goofy smile on her face. It is discovered that to cure Kim of the disease, she must be given someone else's brain, so one of the doctors unscrews his own skull and volunteers his brain for transplant. All of a sudden, everyone else in the room (except for Ron) catches the disease, so Ron has to take the brain from the doctor, who voluntarily offers it up, and insert into Kim's head. Despite having someone else's brain, she acts as if she was the same as before.
- The closest thing that has been done in real life is Head Transplants on test animals like dogs and monkeys. They were quadriplegic because their spinal cords in the head and torso could not attach, but they could breathe and eat, though vocalization is unlikely. Fortunately, to our knowledge it has never been attempted with humans.
- Dr. Sergio Canavero has been working on a head transplant variation of this. Claiming success with animal testing, and a successful dry run on cadavers.