Effect of Neuropeptide Y Injected into the Hypothalamic Suprachiasmatic Nucleus or the Lateral Cerebral Ventricle on Food Intake

The effects of neuropeptide Y (NPY) injected into the hypothalamic suprachiasmatic nucleus (SCN) or the lateral cerebral ventricle (LCV) at four different time points of the day on the subsequent 2h food intake from three macronutrient rich diets were examined. Adult Wistar male rats on 12-12 h light-dark cycles received either saline or NPY (lOOpmol) through chronically implanted guide cannulas into the SCN or the LCV. The results show that NPY was effective at stimulating energy intake from the dextrin/sucrose diet when injected in the SCN after lights-on, and total energy intake when injected in the LCV before and after lights-on. This suggests that NPY is effective at altering nychthemeral variations in total energy and energy from dextrin/sucrose diets, but this modulation is specific to the site of administration.