David Hubel: In Memoriam

Hydraulic microelectrode advancermade by David Hubel David Hubel was a giant in our field, yet he waswarm, friendly, and humble in person. He and Torsten Wiesel, following in the footsteps of their mentor Steve Kuffler, discovered fundamental principles of information processing in the brain and fundamental principles of how the brain wires itself up. I think many people in the field see David as a formidable figure, but since I saw him every day in the lab, that is the person I will remember here. After all, it is the guy in the lab who did the work that made him great, and there is surely some connection between the way he daily went about doing science and how successful he was. David always saw himself as lucky, as having simply been in the right place at the right time. But I think two characteristics I saw all the time, his mechanical inventiveness and his perseverance, were more important than luck. He and Torsten started recording in visual cortex when there was hardly anyone else doing that. But the reason they could do this is because David had invented the tungsten microelectrode, which allowed them to record from single neurons, not axons, which is what people had been recording with glass pipettes, and David had invented a way of sealing the electrode advancer to the cortex so that cortical pulsations did not prevent them from holding single units long enough to characterize them. David, like his mentor Steve Kuffler, did not do science with a lot of theoretical preconceptions; instead, their approach was to figure out some simple way to isolate, insulate, amplify, visualize, record, or stimulate some part of the nervous system. Until his death, Steve Kuffler always did his own experiments; he was constantly inventing new preparations and always did his own elegant dissections. David always did his own experiments and distained people who took credit for their students’ and postdocs’ work. He made what he needed to do the experiments he wanted to do. He got advice from everyone he could find in order to figure out how to make electrodes out of tungsten wire because he found glass pipettes too fragile and too fussy. He often told me that the most useful advice he got was from the departmental machinist because he knew all about metals. He figured out how to make an electrode by dipping fine tungsten wire in potassium nitrite, while passing current through the wire, which etches the tip until it is very pointy; then you dip the electrode, upside down, in lacquer to insulate all but the tip. You then have to test the electrode to make sure the entire shaft is insulated (you look for bubbles as you pass current through the electrode). You cannot make electrodes in the summer because humidity makes for leaky electrodes. David made his own electrodes for decades and taught me how tomake them.When he started borrowing mine, I learned that Frederick Haer would sell us electrodes, made exactly by David’s recipe. David had a lathe that he