Effect of Hypothalamic Lesions on the Peripheral Blood Picture of the Gat

This investigation was carried out in an attempt to verify reports in the literature to the effect that the peripheral blood picture may be influenced by the vegetative centers of the brain. The study was made using adult male and female cats which had undergone operations to produce bilateral lesions in the hypothalamus for induction of possible behavior changes. When the behavior study was completed, the animals were killed with ether, their brains fixed in formalin, embedded and sectioned for study of the areas damaged (1).

Method. The following data consist of a series of conventional blood counts and differential counts obtained from ear vein blood of 9 male and 19 female cats. The blood samples were collected for a period both before and after the production of the hypothalamic lesions. Blood counts were made with the standard pipettes and a Spencer haemacytometer. Differential counts were made after staining the smears with Wright's stain. The blood samples were taken at approximately the same time of day in each case in order to control the diurnal variations that are known to occur (2). Time of feeding was recorded in view of the possible effect it might have on the blood picture(3,4). The animals were handled as gently and quietly as possible in order to avoid emotional disturbances which also are known to have a marked effect on the peripheral blood picture(5). The number of counts made on each animal varied somewhat, ranging from 6 to 9 in the preoperative period and from 6 to 8 counts in the post-operative period.

Findings. In the normal cats the blood picture before operation showed an average WBC count of 20,017 for the males, with a range from 10,361 to 28,950.