50 Years Ago

'Extracorporeal perfusion of the isolated head of a dog' — Critical evaluation of cerebral metabolism and intracranial fluid distribution necessitates complete isolation of the brain's blood supply; however, brain viability must be demonstrated and maintained for such studies to be meaningful ... In order to minimize handling of the brain substance, a factor which may disturb fluid distribution and cerebral metabolism, we have chosen to leave the brain within the skull during perfusion ... Most cortical activity ceased when blood glucose was depleted ... Even after the electrocortical activity ceased, corneal and lid reflexes remained intact and the oxygen and glucose consumption continued ... From our experience, we believe that electrocortical activity is a sensitive index of brain viability, in that it is lost long before inactivation of corneal and lid reflexes or cessation of metabolism. In this preparation we have demonstrated that the dog brain maintains this activity for several hours after complete decapitation.

From Nature 25 April 1964

100 Years Ago

The second reading of a Bill to prohibit experiments on dogs was carried in the House of Commons on Friday last, April 17, by a majority of forty-two ... It was stated on behalf of the Government that an amendment will be moved in Committee to abolish the proposed prohibition and to allow experiments only in cases where no other animal but a dog is available for the purpose ... Before the second reading was taken, a memorial signed by more than three hundred eminent physicians, surgeons, and other scientific investigators, protesting against the measure, was addressed to the Home Secretary.

From Nature 23 April 1914