|
-342234224
|
Neurons IonicCurrents
68 records
|
the measured rise in [Ca2+]i and to additionally test whether the
voltage-gated Na+ channel activity might influence the initiation site or
spatial extent of the plateau, plateaus were evoked in an additional 10 cells
bathed in 100 µM AP-5 plus 1 µM TTX. Figure 5 illustrates typical results when
both Na+ channels and NMDA receptors were blocked. Plateaus were evoked in
each cell tested under these conditions, and the spatio-temporal pattern of
the rise of [Ca2+]i and the spatial extent of these plateaus were similar to
those obtained in physiological saline. In these experiments, the estimated
proximal extent of the plateaus ranged from 15 to 88 µm (mean: 53.1 µm) and
the distal extent ranged from 22 to 146 µm (mean: 49.5 µm). These values were
not significantly different from those obtained in physiological saline (for
proximal extent P = 0.46; for distal extent P = 0.94; 2-tailed Student's
t-test). As found for physiological saline, the proximal extent of plateaus
evoked in AP-5 plus TTX was not significantly different from teh distal extent
(P = 0.81, 2-tailed Students t-test). Data obtained from plateaus evoked in
AP-5 plus TTX are plotted as triangles in Fig. 4 for comparison with plateaus
evoked in physiological saline."p.509
