The Purring Center in Cats

Large black spots show points from which stimulation elicited purring. Small black spots show points in these sections which were stimulated without eliciting purring. Numerous other points in other sections were stimulated with negative results so far as purring was concerned (Gibbs & Gibbs, 1936).


A 1936 study by Gibbs and Gibbs identified the infundibular region (which connects the hypothalamus and the posterior pituitary) as the purring center in the cat's brain:

In the course of a study which we conducted on the convulsion threshold of various parts of the cat’s brain, a region was found which when stimulated caused purring. This reaction was so striking and the region from which it was obtained so definitely localized that we consider it worthy of a special report.

Our experiments were conducted on 400 cats.

. . .

The points stimulated in our 400 experiments were fairly well scattered through the brain (Gibbs and Gibbs, ’36). In only three cases, however, did we obtain purring as a response to stimulation. In each this was the first response to weak stimulation; it was obtained with the secondary coil at 10 cm. or more from the primary. In all three cases the tip of the needle lay in the infundibular region (see figures).

CONCLUSION

Purring can be elicited by electrical stimulation in the infundibular region of the cat’s brain.

400 cats!

Some of the 400 cats that were rescued from a market in Tianjin. 

Photograph: China Photos/Getty Images.

ADDENDUM (March 11 2013): Just to be crystal clear, the main reason the authors conducted the study in the first place was to determine seizure thresholds in different parts of the cat brain, not to find the purring center. They did not lay out the rationale for the seizure study in the purring paper, but see abstract below.

GIBBS, F. A. AND E. L. GIBBS (1936). The convulsion threshold of various parts of the cat’s brain. Arch. Neurol and Psychiat., vol. 35, pp. 109-116.

In this investigation we have attempted to determine the relative ease or difficulty with which convulsions can be produced by electrical stimulation of various parts of the cat's brain. The problem has significance because it bears directly on the question of whether or not a special part of the brain is concerned with the production of convulsions, a question of major importance to those interested in the etiology of epileptic seizures.

According to Wikipedia:

Frederic Andrews Gibbs (1903–1992) was an American neurologist who was a pioneer in the use of electroencephalography (EEG) for the diagnosis and treatment of epilepsy.

Reference

Gibbs EL, Gibbs FA. (1936). A purring center in the cat's brain. Journal of Comparative Neurology 64: 209–211.

Basal view of a human brain
(Infundibulum labeled third from the top on right).