Intracellular recording and labeling of neurons in midline structures of the rat brain in vivo using sharp electrodes

In this paper we emphasize three important aspects of intracellular recording with sharp electrodes and subsequent cell labeling with neurobiotin, utilizing the acute in vivo rat preparation: first, preparing access to the hippocampal formation and overcoming the problems presented by the sagittal sinus in gaining access to the septum for recording; secondly, the mechanical stabilization of the in vivo preparation in order to reduce brain movements due to respiration and heart beat; and thirdly, fabrication and filling of sharp glass recording electrodes which can be used for successful intracellular recording and labeling. We present examples of such successful electrophysiogical recording and labeling of hippocampal and septal neurons.