Figure 6.

Schematic representation of the Guillain–Mollaret triangle formed by connections between the deep cerebellar nuclei and contralateral inferior olive, which pass near the red nucleus (A). The conduction strength through the dendrodendritic gap junctions (schematized with yellow connexon channels; DD) between adjacent inferior olivary neurons are inhibited by projections from the deep cerebellar nuclei (blue projection) (B). Lesions in the Guillain–Mollaret triangle [red X in (A,B)] also result in hypertrophy of inferior olive neurons causing development of abnormal soma-somatic gap junction. Schematic representation of a model for classical delay conditioning (C,D). Model and traces from simulations after inferior olive hypertrophy but before cerebellar learning (C). Inferior olive and cerebellar modules after hypertrophy and learning (D). Lower left corner shows icon for semicircular canals (C,D). Simulated membrane potentials (black), eye oscillations (magenta). CF, climbing fibers; PF, parallel fibers; DD, dendrodendritic gap junction; SS, soma-somatic gap junction; Gr, granule cell layer; IN, interneurons; PC, Purkinje neurons [(27) with permission for reproduction of material].