Figure 6.
Glomerular astrocytes detect the glutamate released at olfactory nerve terminals. A, The initial fast component of the astrocyte current recorded in the presence of AP-5 and NBQX (black trace) was blocked by TBOA (50 μm, see inset), consistent with a synaptic transporter current. However, TBOA also facilitated the slow potassium component of the astrocyte response (compare gray and black traces). B, The astrocyte response still contained a transporter current (inset) when mGluR1 receptors were blocked with LY367385 (25-50 μm), but the potentiation of the K+ current by TBOA was much less prominent. C, The effects of TBOA are shown as a percentage of the total charge measured in the absence of receptor or transporter blockers. D, The mGluR1 blocker LY367385 had no effect on the synaptic transporter current, but it reduced the astrocyte potassium current. In A, B, and D, AP-5 (150 μm) and NBQX (20 μm) were present throughout the recording. LY, LY367385.