RT Journal Article
SR Electronic
T1 Diverse Synaptic Mechanisms Generate Direction Selectivity in the Rabbit Retina
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 7712
OP 7720
DO 10.1523/JNEUROSCI.22-17-07712.2002
VO 22
IS 17
A1 W. Rowland Taylor
A1 David I. Vaney
YR 2002
UL http://www.jneurosci.org/content/22/17/7712.abstract
AB The synaptic conductance of the On–Off direction-selective ganglion cells was measured during visual stimulation to determine whether the direction selectivity is a property of the circuitry presynaptic to the ganglion cells or is generated by postsynaptic interaction of excitatory and inhibitory inputs. Three synaptic asymmetries were identified that contribute to the generation of direction-selective responses: (1) a presynaptic mechanism producing stronger excitation in the preferred direction, (2) a presynaptic mechanism producing stronger inhibition in the opposite direction, and (3) postsynaptic interaction of excitation with spatially offset inhibition. Although the on- and off-responses showed the same directional tuning, the off-response was generated by all three mechanisms, whereas the on-response was generated primarily by the two presynaptic mechanisms. The results indicate that, within a single neuron, different strategies are used within distinct dendritic arbors to accomplish the same neural computation.