Isolated Brain

Isolated Brain


a brain (or head) that is completely separated from the body but can nevertheless (for some time) maintain vital activities, given conditions approximating the natural physiological state.

As early as the 1920’s, S.S. Briukhonenko designed the autojector, the first artificial circulatory apparatus in the world. A completely isolated dog’s head, hooked up to this apparatus, maintained life activity for several hours. The American surgeon R. White was the first to succeed in isolating the head of a monkey, whose blood supply was provided either by a special apparatus or from another, donor, monkey. The experiment was conducted under conditions of deep hypothermia, with the use of complex physiological and biochemical methods of monitoring the state of the isolated head. Evidence of the preservation of the life activity of the isolated head for several days was provided by the character of the biopotentials of the isolated head, the metabolic state, and the appearance on the electroencephalogram (EEG) of specific convulsive discharges after the introduction into the blood nourishing the head of substances that produce epileptic convulsions.

The isolated brain is important as an experimental model, suitable for studying certain problems of the physiology, biochemistry, and pathology of the central nervous system, including the mechanisms of brain activity, the relationships of the cortex and subcortex, and the nature of bioelectric activity. The specimens are obtained by severing the brain stem at certain levels, at the same time preserving blood circulation and certain neural connections (F. Bremer, 1937). One specimen (cerveau isolé) is obtained by severing the brain stem between the superior and inferior colliculi of the quadrigeminum. Only the first three pairs of cranial nerves (olfactory, visual, and oculomotor) retain their connection with the brain. Slow waves, typical of drowsiness and sleep, are recorded on the EEG. If the cut is made at the spinobulbar level, a specimen (encéphale isolé) is obtained whose EEG shows activity characteristic of wakefulness. The “behavior” of the head conforms te- the data of the EEG.


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They suggest it may be the structure of these extended networks more than the size of any isolated brain region that is critical for cognitive functioning.
Using cell recordings carried out on isolated brain sections, they analysed the long-term potentiation in the hippocampus.
Isolated brain stem tuberculoma presenting with one and a half syndrome.
However, in isolated brain preparations 5-HT elicits swim motor patterns in the swim CPG and accelerates ongoing swim motor patterns (14).
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London, September 11 ( ANI ): Case Western Reserve researchers have discovered how to store diverse forms of artificial short-term memories in isolated brain tissue.
The type of activity we triggered in isolated brain sections was similar to what other researchers have demonstrated in monkeys taught to perform short-term memory tasks.
The isolated brain was pinned in a small (2-5 ml) Sylgard-lined acrylic plastic chamber that was maintained at 11-15 [degrees]C by circulating ambient seawater or antifreeze, from a temperature-controlled water bath, through an aluminum cooling jacket surrounding the chamber.
This procedure isolated brain activity uniquely linked to the conscious recollection of words, the researchers argue.
These men were not just isolated brains in vats--Hilary Putnam's image--but fully embodied, responding to the place and time in which they found themselves: in European and Pacific theatres of war, in a Cold War America promoting science, technology and planning, in dingy University basements or attics engaging with calculating machines and early computers, and in 1960s NSF workshops, or at exotic foreign conferences, or on the streets protesting for civil rights in Seattle, Detroit and Baltimore.
Fortunately, evolution equipped mammals with a biological mechanism for bridging the gap between isolated brains so that pairs of animals in a species can reproduce and raise their offspring, Freeman argues.