A ventral approach to stereotaxy of the guinea pig brain.

The guinea pig (Cavia porcellus) is a species frequently used in neuromorphological and neurophysiological studies. Some experimental data suggest that the guinea pig might also be used to develop an animal model of Alzheimer's disease. These studies would require microsurgical manipulations of the nervous system. The present paper describes a method for ventral stereotaxic intrusions in the guinea pig brain through the oval foramen at the skull base. The topographic relationships of the bony landmarks to major parts of the central nervous system and the cranial nerves are analysed, and the results are tested by intrahippocampal injection of horseradish peroxidase.