Introduction

Abstract

The rat brain is the most widely used animal model in neurobiology. The frequency of its use underlines the need for stereotaxic atlases of the rat brain. The first attempt to fulfill this requirement was made by Krieg (1946 c), but his atlas contains only very rough data based on 30 schematic drawings of coronal sections. The drawings are exaggeratedly schematic and significantly distorted. This, together with the fact that Krieg delineated far too few structures in the di- and rhombencephalon, makes the accurate placement of electrodes difficult. Accurate electrode placement is essential for advanced techniques in modern neuroanatomical, neurophysiological, and neurochemical studies. Nevertheless, Krieg’s work represents the first delineation of cortical areas in the rat. These delineations were more elaborately produced and partly corroborated by experimental work by Krieg (1946a, b, 1947). Despite its shortcomings, this fundamentally valuable series of reports greatly influenced experimental approaches in the four decades following its publication. The work of König and Klippel (1963) was another land-mark in the development of stereotaxic atlases of the rat brain. This atlas is one of the most widely used works of reference on stereotaxic coordinates of the rat brain.