J. Murdoch Ritchie, 83

Benbo Ritchie was a psychopharmacologist and friend of my father at Albert Einstein Medical College, so I was interested to see his obituary in the New York Times so shortly after my father's death:

In 1975, while a Senate Select Committee on Intelligence was reviewing the C.I.A.’s “operational use” of poisons, Dr. Ritchie asked for access to the agency’s store of saxitoxin, a rare and highly effective neurotoxin made by clams.

The request raised eyebrows in Congress because the substance, which kills by causing respiratory failure, was not even supposed to exist; President Richard M. Nixon had ordered the government to destroy all of its bacteriological weapons in 1969. To the committee’s dismay, the C.I.A. did not turn over its saxitoxin supply, which the agency said was used to prepare suicide pills for spies in case of capture.

In the early 1970s, Dr. Ritchie, who was known as Murdoch, used saxitoxin for a nonlethal purpose, in studies of electrical conduction within nerve cells. It was already known that the nervous system used shifts in levels of sodium and potassium to transfer electrical signals and that saxitoxin could be employed to block the movement of sodium.

Dr. Ritchie, Richard D. Keynes, Gary R. Strichartz and others labeled molecules of the toxin with radioactive tags and introduced them into the living tissue of rabbits, fish and lobsters. They then read the radioactive markers to count the number of sodium entry sites, called channels.

This work, which helped explain fundamental questions about the nervous system, was based on earlier observations made by Dr. Ritchie and Paul Greengard, who studied the action and effects of lidocaine, dibucaine and other local anesthetics on the nerve cells. Like saxitoxin, dibucaine and lidocaine act by blocking the flow of sodium, dulling the sensation of pain.

In a development that surprised Dr. Ritchie, the government decided not to incinerate the saxitoxin and actually offered it to him. But he soon realized how much responsibility for safeguarding it would be involved, and he recommended that the remaining store be donated to the National Institutes of Health instead. Although Dr. Ritchie was not successful in finding an antidote to saxitoxin, which was his original goal, his research shed light on how nerve cells can lose their protective sheaths of myelin, ultimately interrupting the nervous system’s signals and leading to multiple sclerosis.

Working with Robert Byck, a colleague at Yale, [NOTE: Also a friend of my father's] Dr. Ritchie investigated the physiological effects of smoking marijuana. In tests on nerve fibers, they found that the drug’s active component, THC, or tetrahydrocannabinol, had a more pronounced influence than previously thought.