M. Sciancalepore et A. Constanti, PATCH-CLAMP STUDY OF NEURONS IN RAT OLFACTORY CORTEX SLICES - PROPERTIES OF A SLOW POSTSTIMULUS AFTERDEPOLARIZING CURRENT (I-ADP), NeuroReport, 6(18), 1995, pp. 2489-2494
WHOLE-CELL recordings were made from neurones in slices of rat olfacto
ry cortex (10-19 days old), using potassium methylsulphate-filled pipe
ttes. Positive commands applied from -60 mV in the presence of oxotrem
orine-M (10-20 mu M, 20 of 30 cells) or trans-ACPD (10-50 mu M, 4 of 9
cells) evoked a slow inward tail current similar to the K+-mediated t
ail current (I-K,I-ADP) recorded with sharp electrodes. I-ADP was redu
ced by hyperpolarization; showed a 27% decrease in input conductance a
t its peak and was depressed by Cd2+, 4AP or high K+ but unaffected by
Cs+, Ba2+ or TEA (5 mM). I-ADP was significantly larger in cells betw
een postnatal days 13 and 15 than in younger neurones (10-12 days). Th
ese data show that stable whole-cell recordings of I-ADP can be made f
rom olfactory neurones in cortical slices, and support our hypothesis
that I-ADP is a slowly reactivating, Ca2+-sensitive K+ conductance.