This is just freaky.

Panel: Use caution in stem cell study of monkey brains

Scientists hope to grow embryonic stem cells into replacement brain cells to treat neurological disorders such as Parkinson's and Huntington's disease. Safety tests of these treatments would require first implanting the cells in animals, perhaps including primates. However, whether implanting such cells might raise the consciousness of the animals to a higher level, changing the ethics of experimentation, raises some awkward questions, Greely says.

Part human, part animal: research raises concerns

RENO — On a farm about six miles outside this gambling town, Jason Chamberlain looks over a flock of about 50 smelly sheep, many of them possessing partially human livers, hearts, brains and other organs.

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In the past two years, scientists have created pigs with human blood, fused rabbit eggs with human DNA and injected human stem cells to make paralyzed mice walk.

Particularly worrisome to some scientists are the nightmare scenarios that could arise from the mixing of brain cells: What if a human mind somehow got trapped inside a sheep's head?