REPRESENTATION OF THE SYMPATHETIC AND PARASYMPATHETIC NERVOUS SYSTEMS IN THE FOREBRAIN OF THE CAT

Abstract

There has been much controversy as to the distribution of function of the sympathetic and parasympathetic nervous systems in the forebrain, particularly in the hypothalamus. Beattie and Sheehan¹found these systems to be separately represented, parasympathetic effects being obtained in the anterior region of the hypothalamus (tuber cinereum) and sympathetic effects in the posterior region. Ranson and his associates,²however, have obtained sympathetic effects throughout the hypothalamus, including the tuber cinereum, as far forward as the optic chiasm. The only parasympathetic reaction regularly observed by them on hypothalamic stimulation was contraction of the urinary bladder, and this was found on stimulation in front of the optic chiasm. Among sympathetic effects they observed dilatation of the pupils, rise in blood pressure, secretion of epinephrine, secretion of sweat, inhibition of gastrointestinal peristalsis and erection of hair. Masserman and Haertig³obtained parasympathetic effects on the gastrointestinal tract from both the