Avian Cerebrospinal Fluid: Repeated Collection and Testing for a Possible Role in Food Intake Regulation

Abstract The objective of this study was to determine if a factor(s) involved in the regulation of food intake exists in the cerebrospinal fluid (CSF) of the domestic fowl. A technique was developed that allows blood-free CSF samples to be collected repeatedly from the cisterma magna for up to 6 weeks. Using this technique, CSF was collected from free-feeding and 24-hour fasted broiler cockerels and injected into the lateral cerebral ventricle of 8-week old Leghorn cockerels and 4-week old broiler cockerels. The free-feeding birds received 10 μl intracerebroventricular injections of CSF either at normal concentration (1 ×-CSF) (Experiments 1 and 3) or at four times normal concentration (4 ×-CSF) (Experiments 2 and 4). Artificial CSF served as the control. Food and water consumption were monitored following injection. The 1 ×- and 4 ×-CSF collected from both the free-feeding and 24-hour fasted donors did not affect the food intake of either the Leghorn or the broiler recipients. Water intake, however, was significantly increased in the Leghorns and broilers receiving the 4 ×-CSF collected from 24-hour fasted birds. Thus, there does not appear to be a factor(s) present in the CSF collected from the cisterna magna that alters food intake when injected into the lateral ventricle, but a factor may exist in the CSF collected from fasted donors that stimulates water intake.