Figure 7. Summary of inhibitory projections to the IO.

(A) Schematic of inhibitory input from the DCN (top) to the IO (middle, bottom). The DCN supplies asynchronous (green) GABAergic inhibition, primarily targeting the rostral IO. Dashed arrows show putative connections between specific subregions of the DCN and IO. White regions of the IO did not receive detectable input from the DCN. (B) Inhibitory input from vestibular origins (top) to the IO (middle, bottom) provide primarily synchronous (magenta) inhibition that typically has both GABAergic and Glycinergic components. White regions of the IO did not receive detectable input from the vestibular nuclei. Contralateral/ipsilateral specificity is not shown. Sources and properties of inhibition in the rDCK are based on previous studies, which have shown that they have fast kinetics (Best and Regehr, 2009), and originate in the vestibular nuclei but not the cerebellar nuclei (Balaban and Beryozkin, 1994; De Zeeuw et al., 1994; De Zeeuw et al., 1993).