RT Journal Article
SR Electronic
T1 NMDA Receptor Agonists Fail To Alter Release from Cerebellar Basket Cells
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 16550
OP 16555
DO 10.1523/JNEUROSCI.3910-11.2011
VO 31
IS 46
A1 Jason R. Pugh
A1 Craig E. Jahr
YR 2011
UL http://www.jneurosci.org/content/31/46/16550.abstract
AB Previous studies of NMDA receptor (NMDAR) expression on axons of cerebellar molecular layer interneurons have produced conflicting results. We made use of the calcium sensitivity of vesicular release machinery to test for NMDAR activity in basket cell axons. Iontophoresis of l-aspartate, an NMDAR agonist, onto basket cell axon collaterals had no effect on evoked IPSCs measured in synaptically coupled Purkinje cells. Furthermore, calcium indicators in basket cell varicosities did not report any change in intracellular calcium following iontophoresis of l-aspartate or two-photon uncaging of glutamate. In contrast, activation of presynaptic purinergic receptors by iontophoresis of ATP decreased evoked IPSC amplitudes and action potential-evoked calcium transients in axonal varicosities, demonstrating the effectiveness of activating presynaptic receptors by iontophoresis. We find no evidence for functional NMDARs in basket cell varicosities.