. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. NEUROBIOLOGY 185 A 10 B. 70 - CL> O CO 10J 10 0 Intervals (s) Figure 1. Distribution of intervals between minis at hippocampal synapses. A) Minis were acquired in voltage clamp using the Whole-cell recording configuration. Short trains of minis could be seen consistently under these conditions. In these experiments multiple exponentials were always required for best fit of mini-interval distributions indicating a divergence from Poisson's statistics. The histogram presented was best fitted b\ the sum {solid line) of two d
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. NEUROBIOLOGY 185 A 10 B. 70 - CL> O CO 10J 10 0 Intervals (s) Figure 1. Distribution of intervals between minis at hippocampal synapses. A) Minis were acquired in voltage clamp using the Whole-cell recording configuration. Short trains of minis could be seen consistently under these conditions. In these experiments multiple exponentials were always required for best fit of mini-interval distributions indicating a divergence from Poisson's statistics. The histogram presented was best fitted b\ the sum {solid line) of two decaying exponentials {dotted lines). B) Summon' data for the area (af) of the short-inten'al component {range af = 3-66%, mean value = 12 ± 4%; range rf = - ms, mean value ± ins). one observed in the fast component of mini interval distribu- tions, might result from some sort of transient change in pre- synaptic Ca2+ levels (see ref. 6 for review). We have therefore tested the effects of cadmium (50 juM). a broad spectrum Ca2 + channel blocker. When cadmium was applied, no effects on mini frequency and mini amplitude were detected. In 9 cells, the average mini frequency in control conditions was ± Hz. and it was ± Hz after the application of cadmium. In these experiments, when log-binned distributions of mini- intervals were constructed, if multiple decaying exponentials were required for optimal fit in control conditions, they were also required in the presence of Cd2 + (;i = 4/4; P 20 mint (in the presence of tetrodotoxin) produced no significant effect on mini frequency ( = ± Hz, = ± , mean ± sd; n = 7). Importantly, interval-distributions of minis displayed no detect- able change after the BAPTA treatment (n = 3/3: P < ; = 8 ± 3%; = 8 ± 3%). Taken together, these observations rule out a role in the divergence from a random Poisson process for a brief elevation in presynaptic Ca2 + , whether from an
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
