A specific type of neuron might be thwarting researchers' efforts at mapping the connectome by temporarily cloaking the synapses that link a wide field of neurons, report scientists. The researchers found that somatostatin cells send out a signal -- much like a cloaking device - that silences neighboring neurons, making the synapses invisible to researchers. By doing this, somatostatin neurons can change the way the brain functions, heightening some perceptual pathways and silencing others.