Figure 8.

NAAG evoked changes of [Ca²⁺]_i in oligodendrocytes and granule cells. (A) Specimen image of a cerebellar white matter oligodendrocyte patch-clamped with a pipette containing Fura-2. Black line encircles soma, green and red rectangles are around processes aligned with axons. (B) Specimen image of a cerebellar granule cell patch-clamped with a pipette containing Fura-2. Black line encircles soma, red rectangle is around a single process (C) Lack of change of Fura-2 fluorescence in both the soma and processes of the oligodendrocyte in A after application of 1 mM NAAG (upper panel), despite NAAG evoking an inward current (lower panel). (D) Change of Fura-2 fluorescence (▵R = change of ratio 340/380 nm) in the granule cell in B after application of 1 mM NAAG, and block of this response by 100 µM AP5 (upper panel), with the simultaneously evoked inward current (lower panel). (E) Average responses of oligodendrocytes (eight cells) and granule cell somata (seven cells) to 1 mM NAAG. (F) Average responses of granule cell somata to NAAG, NAAG + AP5, and a subsequent application of NAAG (three cells), normalized to the initial response.