B-mode and color Doppler ultrasound imaging for localization of microelectrode in monkey brain

Using alert monkeys, we attempted ultrasound imaging after partial cranioto my to localize a metal microelectrode in the brain. B-mode ultrasonography provided images of sulcus and gyrus patterns of the cerebral cortex, and lo cations of the ventricles and subarachnoid cisterns. As the microelectrode proceeded in the brain, the position of the microelectrode was clearly iden tified. Electrolytic microlesions generated by delivering direct currents v ia the microelectrode could also be detected. Color Doppler imaging of bloo d vessels of the brain was helpful to demarcate deep brain structures and t o avoid accidental injury of the blood vessels by the microelectrode. The u ltrasonography will make it possible to place recording microelectrodes or injection needles accurately in target regions of the brain in physiologica l, anatomical or behavioral experiments. (C) 2000 Elsevier Science Ireland Ltd and the Japan Neuroscience Society. All rights reserved.