Brain Tech

Two posts in one, for each hemisphere of your melon!

First, the cyborg side. Scientists in Israel have managed to build reliable logic gates out of neurons instead of wires. The process itself actually sounds fairly simple: a glass plate is coated with cell repellent then etched with the desired circuit pattern. The pattern itself is coated with a cell-friendly adhesive which forces the cells to grow only in the scratched areas. Because these scratched paths are so thin, the neurons grow in one direction only—forming straight connections around the circuit. This method has been used to replicate an AND logic gate that only produces output when it receives two inputs.

When stimulated with a drug, the neurons send signals around the circuit. By changing the width of the bridges, the researchers are able to control how many axons link to the neuron island, and tune their device to behave like an AND gate. The benefits? While there are doubters about whether brain "circuits" actually resemble logic gates, the researchers involved with the project believe that brain-cell logic circuits could bridge the gap between computers and the nervous system.

But what about your brain issues now? Proxac, Paxil, Zoloft, Celexa...you can soon replace them all with magnets. The FDA has just approved a new option for the depressed and medication-weary: transcranial magnetic stimulation, or TMS.

The TMS device that's been approved is called the NeuroStar. Physicians use it by first finding a patient's motor control region — they hold a wire coil, or basic inductor, around a patient's head, and then send a current through the coil in order to induce a magnetic field. This magnetic field causes an opposite current to flow in the brain, stimulating electrical activity in its cells and creating a physical response in the body. If the patient's motor control region is "zapped" in this way, their arm might suddenly jerk.

Using the location of the motor control region as a guide, psychiatrists then move the NeuroStar to find a patient's prefrontal cortex — where it is believed most mood problems arise. Over the span of six weeks, a patient receives thousands of magnetic pulses in 40-minute treatments that occur five times a week. In the FDA's study, the biggest complaint patients had was about headaches; unlike shock therapy, TMS doesn't seem to carry the risk of memory loss, and it doesn't induce seizures. Its overall advantage over antidepressants, however, is still up in the air.

About 24% who got TMS scored significantly better on standard depression measures after six weeks, compared with 12% who got the sham. That's about as well as patients respond to a single antidepressant. This is good news since one in five patients suffering from depression are treatment-resistant, meaning that they've tried at least two courses of antidepressant medication without adequate results. The FDA's test of TMS didn't use those severely treatment-resistant patients; instead, it focused on 164 patients who had undergone just one unsuccessful course with an antidepressant. There are still lost of questions, but soon folks may be strapping any wire coils to your head. and one day, there may be a world without emos depression.