The impaired learning and reasoning skills seen in people with schizophrenia may be caused by defective connectivity between two brain regions.

Joshua Gordon and Christoph Kellendonk at Columbia University in New York and their colleagues used mice to mimic the abnormal brain activation seen in people with schizophrenia when they perform cognitive tasks.

The researchers genetically engineered mice so that a synthetic compound would reversibly inhibit neurons in the mediodorsal thalamus. They found that even a slight reduction in activity of this brain region altered connectivity with the prefrontal cortex and caused poor cognition.

This implicates the altered brain patterns in humans with the disease as a contributor to rather than a consequence of cognitive deficits, the authors say.

Neuron 77, 1151–1162 (2013)