Methods for implanting steroid-containing cannulae into the paraventricular nucleus of neonatal rats

Implantation of cannulae into brains of neonatal rats presents methodological difficulties. We discuss such issues as avoiding tissue injury, and describe successful techniques. Cannulae size, methods of preparation, insertion, and securing are evaluated. We present a modified cannula holder applicable to the soft neonatal brain. Application of these methods to the study of glucocorticoid receptors in the neonatal rat hypothalamus is illustrated.