The enumeration, i.e. measurement of the total number, of pituicytes, the glial-type cells of the posterior pituitary whose main role is to assist in the storage and release of neurohypophysial hormones such as oxytocin and vasopressin, in a specified sample of pituitary gland, the small, oval endocrine gland attached to the base of the vertebrate brain and consisting of an anterior and posterior lobe, the secretions of which control the other endocrine glands and influence growth, metabolism, and maturation.