Major brain impact arises from few cells

Neurons called vasoactive intestinal peptide (VIP) cells make up just 1 percent of all brain cells, but their disruption in mice causes symptoms that mimic those of humans with schizophrenia, reports a study by Jessica A. Cardin, Ph.D., associate professor of neuroscience, published on August 16 in Neuron.

Cardin and her team mutated VIP cells in young mice, then observed the consequences in the visual cortex.

VIP cells usually fire when mice start to walk, but they did not do so in the mutant mice. The mutant mice also had reduced synchrony of neuronal firing and impaired vision. The failure of neurons to respond to changes in behavioral state, of which walking is one example, is characteristic of neurodevelopmental disorders such as autism and schizophrenia, as are reduced firing synchrony and perception problems.

In the mice, all of these symptoms emerged by adolescence, the time when, in humans, schizophrenia typically begins. These correspondences between mice with mutated VIP neurons and conditions of neurodevelopmental disease suggest to Cardin that VIP neurons may represent a therapeutic target.