 |
Experiment-based Applications
Synaptic Plasticity
Single Unit Activity
Rhythmic Activity
Muscle Propagation
and Pacing
QT Prolongation
Pharmacology and
Drug Testing
--------------------
Preparation-Based Applications
|
MED64 APPLICATIONS
Rhythmic Activity
Example 1: Rhythmic activity in the hippocampus

K. Shimono et al. J. Neurosci. 15, 8462-8473 (2000) |
A. Micrograph of a hippocampal slice on a MED probe. (MED-P515A: 150µm inter-polar distance)
B. Spontaneous rhythmic activity in the presence of 50 µM Carbachol.
C. Fast Fourier transforms displaying the frequency (x-axis) and amplitude (y-axis) of rhythmic activity.
D. Current source density analyses of carbachol-induced activity. The pseudo-colored panels show the computed current source density in the different regions of the electrode array at several time points during a carbachol-induced oscillation. The outlines of the pyramidal and granule cell fields and their apical dendrites are overlayed. At 0ms, a sink appears in the apical dendrites of the border between fields CA3 and CA1 with a corresponding source in the basal dendrites. The fields merge and intensify and then dissipate after ~12ms. At ~20ms, a source appears in the apical dendrites with a corresponding sink in the basal dendrites. These
expand and intensify before dissipating at ~40ms, after which an apical sink reappears to reinitiate the cycle.
|
Example 2: Circadian activities

|
A. A phase-contrast photomicrograph of a cultured SCN slice on the MED probe after 14d in culture. (MED-P210A, 100µm inter-polar distance) Scale bar, 150µm
B. Representative circadian firing rhythms of SCN neurons from Clock mutant and wild-type mice in slice cultures.
The firing rhythm was expressed in a histogram of the mean firing rate every 15min. and double-plotted. The numbers in the right margin of the first lane in each panel were the scales of firing rate. The circadian periods of these firing rhythms were 28.1h (left) and 28.0h (right) for Clock/Clock, 25.3h and 24.5h for Clock/+, and 23.3h and 23.8h for +/+ neurons, respectively.
Nakamura, W. et al. Nature Neuroscience, 5, 399-400 (2002)
|
Example 3: Endogenous hippocampal beta rhythm
Acute slices from adult rat hippocampus were placed on a MED probe. Infusion of carbachol (50μM), a cholinergic agonist, triggered spontaneous beta waves in pyramidal regions in 41/55 slices.
Current source density analysis indicated that during each cycle (panel numbers refer to time during the 42ms cycle) a sink appeared in field CA3 that extended to CA1 (0-9ms) where it dissipated (15ms). This was followed by corresponding sources mirroring the sinks of the previous half cycle, in the same regions (21-36ms).
Based on data provided by G. Lynch (1999), UC Irvine.
|