Extended Data Fig. 4: Excitatory and inhibitory synaptic inputs mapped onto reconstructed cell somata.
From: Light-microscopy-based connectomic reconstruction of mammalian brain tissue
Reconstruction of four example cell somata from LICONN datasets in somatosensory cortex with immunolabelling for SHANK2 and gephyrin. Excitatory (magenta) and inhibitory (yellow) synaptic inputs are mapped onto cell body reconstructions. Synapses were classified as excitatory if (1) a typical presynaptic structure, (2) a PSD and (3) SHANK2 were present. Synapses were classified as inhibitory if (1) a presynaptic structure was present and (2) a PSD was missing, with or without gephyrin. For each cell body, the number of excitatory and inhibitory connections are indicated, showing a much higher number of inhibitory inputs. The one cell on the right displayed a reversed pattern with 30 SHANK2-positive synapses. We analysed 13 cell bodies (contained ≥50% within the imaging volume) across 8 datasets and counted 48.7 ± 19.8 (mean ± s.d.) inhibitory synapses per soma (excluding the one cell with reversed input preference displayed on the right). Excitatory synapses were sparse, with most somata receiving 0 and one soma receiving 1 excitatory input.
