Roger nodded and inserted a long cylindrical greenish “monkey chow” pellet into a mesh opening of Elvis’s cage. The animal snatched it to his mouth with a lightning-fast motion.
“There are also the sequence learning tests,” said Susan. “Before we started him on synaptine, it took about four repetitions before he learned a new sequence. Now he always gets them after the second repetition and often after the first. Is that a 100 percent increase in IQ? Or a 50 percent increase? Or is it nonsense to apply a one-dimensional measure like IQ to a characteristic with as many independent variables as intelligence seems to have? All I can say is that I’m sure Elvis is much brighter than he was a few weeks ago.”
Roger nodded. “How long does a dose of synaptine last? Or is it permanent?”
“The protein is metabolized, so it has to be replaced. With Elvis an intramuscular dose lasts about twelve hours. But there’s some evidence of residual benefits that last much longer. With the rats it’s more difficult to tell, because the effect is so much smaller.”
“Smaller in rats…” Roger mused, trying to recall what she had said about the tests. “Oh yes, you were doing trials with rats until a few weeks ago, weren’t you?” If the increase in intelligence is small in a rat and bigger in a monkey, what would it be for a human? he wondered.
She nodded. “That series was disappointing. Synaptine didn’t do much for rats, for some reason,” she said. “In low doses it made them meaner, and in large doses it gave them seizures, but the effect of what should be a normal dose was only a slight improvement in their T-maze running performance.”
“Any theories as to why?”
“We did some autoradiographs of brain tissues with carbon-14-laeled synaptine. The stuff is quite selective. It’s active mainly in the prefrontal brain areas of primates, and rats don’t have any prefrontal development to speak of. Probably there are different versions of the same basic molecule that operate with different types of neurons.”
Roger peered closely at Elvis again. “Any evidence of side effects with this guy?” he asked, walking around to the side of the cage. Untested experimental drugs could be dangerous, he knew.
“Nothing obvious, certainly,” Susan answered. “His weight has been a constant six kilos, his appetite is good, and his coordination, like his reaction time, has improved. Synaptine is a natural protein, if a rare one. Primates already have some quantity of it in their brain tissue, so raising the concentration wouldn’t be expected to do unpleasant things, unless the dose was very large. That’s the argument we’re using to persuade the Food and Drug Administration, so they’ll approve our application for preliminary human trials to try small doses on certain retarded children, Alzheimer’s patients, and others that show evidence of a synaptine deficiency.”
Morons and the hopelessly senile, he thought. What a waste. “Is it going to be expensive as a drug?” he asked.
Susan grinned. “All the market will bear, as we money-grubbing biotech business folk say.” Then she grew more serious. “In my experience, Roger, you physicists with your big federal grants don’t have much appreciation for the realities of commercial research. We have a huge research overhead here” — she gestured at the long racks of electronic and chemical equipment in the laboratory — “which has to be supported from the profits of our relatively few commercially successful products. If we can’t do that, we go out of business, and the research stops. Mitocon has made it as a successful business so far. We’ve survived two biotech shakeouts in which many similar companies were liquidated or bought out. Appropriately enough, biotechnology is a very Darwinian business.”
“I think it also helps to have an instinct for the jugular,” said Roger, looking at her. It helps in theoretical physics, too, he added silently.
“Perhaps,” said Susan. “Since you asked, the actual production costs of synaptine will be fairly low. For a neuroprotein, it isn’t very complicated. A good solid-phase synthesizer could sequence a batch of it in a few weeks if necessary, but we have better ways. We’ve already located the coding sequence in human DNA and inserted it into e coli bacteria. If necessary we could produce it by the ton. Synaptine is very stable at room temperature and doesn’t even need to be refrigerated. There are none of the usual storage problems, which lowers the cost.”
She picked a vial of bright yellow liquid from a nearby rack half-filled with similar ones and held it up to the light. “Now I’m going to give Elvis his booster shot.”
Roger walked over to the rack. There were many vials there.
“By the way, Roger,” Susan said. “Would you count those vials for me? A new batch arrived just before quitting time, and apparently the carton had been dropped in shipment. A number of the vials were smashed. My technician cleaned up the mess, but he didn’t have time to do a new inventory before he had to leave. Just write the count here.” She indicated a clipboard on the table, pointing to a blank line on a printed form.
“Glad to,” said Roger. As she worked, he moved between her and the long rack of synaptine vials. “And you discovered synaptine? Yourself? I’d wager there’s a good story there,” he said. His index finger moved along the rack as he counted.
She smiled. “Perhaps,” she said. “I owe it all to your fellow countryman Francis Crick, actually. I’m sure you must know about neural networks. Uh, the electronic kind, I mean.” She removed a very thin disposable syringe from a drawer, stripped off the sterile wrapper, attached a needle, and inserted it in the pink top seal of the synaptine vial.
“Of course,” said Roger, writing a number on the clipboard. “The computer that doesn’t need a program. Our experimenters at the Super Collider have trained neural nets to distinguish good data events from garbage. The circuits have solved many problems of pattern recognition in situations where conventional computers have failed miserably. And I seem to recall that molecular biologists trained them to predict protein folding.” He watched as she withdrew about half a milliliter of the vial’s contents. “Doesn’t take much,” he observed.
She nodded. “Some years ago when neural nets were first being investigated, Sir Francis Crick of DNA fame publicly objected to calling them ‘neural’ networks. He pointed out that the electronic ‘neural networks’ were using an external procedure to adjust the transmission weights between the connections of the net depending on the net response to a stimulus, the so-called back-propagation algorithm, and that there were no similar processes in natural networks of real neurons.
“Since the two types of networks obviously operated on different principles, Crick contended that it was misleading, even intellectually dishonest, to call the electronic device a ‘neural’ network, which carried the implication that it was an electronic model of the brain.” She slipped the needle beneath the skin of the animal’s pink buttocks. Elvis squealed in protest, but it was a mild protest.
“I perhaps read that somewhere,” said Roger. “But I suppose the terminology was too firmly entrenched by the time Crick complained. People still call them neural networks.”
“So it seems,” said Susan. “For a long time I’ve been interested in brain function, and occasionally I’ve thought about Crick’s argument. A couple of years ago, while I was driving along the Nantucket coast after a conference, I happened to consider it from a different perspective. I had a wonderful insight.” She smiled and seemed to be recalling the thrill. “Electronic neural nets work very well. If the method of weight adjustment they employ is so useful,” she said, raising her eyebrows and looking inquiringly at Roger, “why doesn’t nature use a similar process in real neurons?” She smiled at him, waiting for his answer.