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THE regular ebb and flow of breathing is driven by a group of nerve cells
above the spinal column, say Californian researchers who have pinpointed a
breathing 鈥減acemaker鈥� in rats. Disruption to the pacemaker may be behind
respiratory abnormalities such as sleep apnoea, where people stop breathing
while they are asleep.

Jack Feldman of the University of California in Los Angeles and his
colleagues had already traced the pacemaker activity to a region of brainstem
above the spinal column dubbed the preB枚tzinger Complex. Destroying the
region stopped the rats breathing, and a slice of this brain tissue could
maintain the electrical impulses of rhythmic breathing, but the team weren鈥檛
sure exactly which neurons were involved.

Feldman鈥檚 team hunted for their target neurons with fluorescent antibodies
that bind to the same receptors on the nerve cells as drugs that alter the pace
of breathing. The fluorescent antibodies highlighted one particular part of the
preB枚tzinger Complex.

When neurons from this area were put in a dish, they started firing with the
same rhythm, but slightly ahead of the breathing impulse measured from the
output nerves. This suggests that the cells form a 鈥渒ernel鈥� that drives the
rhythm. 鈥淣ow we can really focus on this region and do very basic neuroscience,鈥�
says Feldman.

鈥淚t鈥檚 great work and an important contribution to the field,鈥� says
neurobiologist Jan-Marino Ramirez of the University of Chicago in Illinois. To
test his ideas, Feldman wants to use drugs to kill the neurons. 鈥淚f our model is
right, then breathing should just go away.鈥�