TY - JOUR
T1 - NMDA receptor agonists fail to alter release from cerebellar basket cells
AU - Pugh, Jason R.
AU - Jahr, Craig E.
PY - 2011/11/16
Y1 - 2011/11/16
N2 - Previous studies ofNMDAreceptor (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, anNMDARagonist, 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.
AB - Previous studies ofNMDAreceptor (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, anNMDARagonist, 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.
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U2 - 10.1523/JNEUROSCI.3910-11.2011
DO - 10.1523/JNEUROSCI.3910-11.2011
M3 - Article
C2 - 22090481
AN - SCOPUS:81255211984
SN - 0270-6474
VL - 31
SP - 16550
EP - 16555
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 46
ER -