Both Immature and Mature Granule Cells Have Slow NMDA Kinetics and Rectifying AMPA Receptors in Swiss Webster Mice.

<p>A. NMDA currents recorded at +40 mV in response to medial perforant path stimulation in a mature granule cell (left) and from and EGFP-positive newborn neurons (right). Recordings were fit with a double exponential equation and the fit is overlaid (red lines). B. The NMDA receptor mediated EPSC in newborn neurons is blocked by ifenprodil. Panel on left shows the normalized NMDA-receptor mediated EPSC amplitude for one cell recorded at +40 mV before and following application of 5 µM ifenprodil. The EPSCs recorded at the indicated time points are superimposed on the right. C. AMPA-receptor mediated synaptic currents recorded over a range of membrane potentials from −80 to +40 mV following blockade of NMDA receptor currents with d-AP5. Currents were normalized to the peak current recorded at −80 mV and plotted against voltage to demonstrate the slight rectification at depolarized potentials in both mature (black traces) and newborn (green traces) granule cells. The peak current-voltage relationship for the two cell types are shown on the right.