The extensive dendritic trees of neurons are by no means passive receivers but are actively involved in processing and transforming synaptic inputs. Wei et al. examined the passive and active transformations that an individual dendritic terminal segment performs on its excitatory inputs. By combining electrophysiological recordings at the cell bodies of hippocampal pyramidal neurons in organotypic cultures and visually guided local application of caged glutamate over dendritic arbors, they showed that distal arbors may generate an all-or-none regenerative response that spreads in a restricted dendritic region. These results now demonstrate directly that dendritic trees can be partitioned into independent functional subunits and that voltage-dependent calcium channels play a crucial role in this compartmentalization.
D.-S. Wei, Y.-A. Mei, A. Bagal, J. P. Y. Kao, S. M. Thompson, C.-M. Tang, Compartmentalized and binary behavior of terminal dendrites in hippocampal pyramidal neurons. Science 293, 2272-2275 (2001). [Abstract] [Full Text]