Close encounters: how cortical neurons find and connect to their correct synaptic partners depends on the cell type.
In this issue of Neuron, Stepanyants et al. embark on quantitative analyses of the axonal and dendritic arbors of cortical neurons. They test whether the paths taken by axons actually bring them closer to their true synaptic partners than they would have gotten by chance encounters based on the same axon trajectories. The results depend on the type of presynaptic neuron. Inhibitory cells take paths that explicitly link them to their actual partners while excitatory axons are as likely to have close encounters with actual partners as with other neurons. These results suggest that the mechanisms for selectivity depend on the type of presynaptic neuron.
Callaway
Edward M
EM
Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000737:chemistry / Q000502:physiology*; D017729:Presynaptic Terminals / Q000502:physiology; D013569:Synapses / Q000502:physiology*