Localization of entorhinal cortex neurons projecting to the dorsal hippocampal formation--a stereotaxic tool in three dimensions.

After topical injection of horseradish peroxidase into the dorsal hippocampal formation, the distribution of retrogradely labelled neurons of the entorhinal cortex was investigated. The distribution of these cells, which are projecting to the dorsal hippocampal formation, is demonstrated by drawings representing series of frontal, sagittal and horizontal sections and including stereotaxic coordinates. These drawings can be used as a morphological and stereotaxic tool in neurobiological research. Controversial opinions as to the dividing of the entorhinal cortex into subfields are discussed.