Fig 1.

Cultured striatal spiny projection neurons are connected through a monosynaptic, fast synaptic transmission. (A) Anatomical reconstruction of two monosynaptically connected spiny projection neurons from cortex-striatum-substantia nigra organotypic culture (Neurobiotin). (Inset) Striatal area during dual whole-cell patch recording from contiguous medium-sized, spherical cell bodies (light-microscopic picture, Hoffman modulation contrast). [Bar = 100 μm, 10 μm in Inset.] (B) Cultured spiny projection neurons with early rectification on depolarization (filled arrow), delayed action potential firing, and anomalous rectification (open arrow) in response to equidistant somatic current pulses (V_{Rest I} = −81 mV and V_{Rest II} = −76 mV). (C) I–V relationship for cultured neurons (±SD; n = 70). Note the strong anomalous rectification below −100 mV (filled arrow). (D) Postsynaptic responses in two reciprocally connected spiny projection neurons from B at rest. Four individual responses including two failures are plotted for each connection. Connections had failure rates of 9% (I → II) and 87% (II → I). (E) Average PSP and corresponding distribution of peak amplitudes for each connection in D (gray area indicates SEM, failures excluded). Same scale as in D.