Extended Data Fig. 9: Local interneuron inputs to the putative CDNs are highly varied and likely inhibitory.

(a) The 24 strongest inputs to the CDNs from within the AG show highly varied anatomy, rather than resembling any specific cell class. (b) The neurons with the most ambiguous neurotransmitter predictions (circled in panel a) do not have anatomy closely approximating the labeling by our TH-Gal4 line. (c) The neurons that most strongly innervate the CDNs from within the AG are predicted to be inhibitory (either through GABA or glutamate) and do not receive reciprocal synapses from the CDNs, again arguing against a primary role for recurrence in their ability to integrate inputs. (d) Each individual cell in Clusters 1 and 2 of Extended Data Fig. 8 receives relatively little reciprocal innervation from its postsynaptic targets, especially as compared to the other GABAergic neuron classes. (e) Pooling the CDNs suggests an increase in reciprocal innervation across the cell class, suggesting that many post-synaptic targets of each putative CDN innervates other CDNs. The diagonal of these plots is still much less dense in Clusters 1 and 2, implying that these cells are less recurrently connected than other morphologically-similar interneurons of the AG.