Chapter 28, Problem 9TYK

Using microelectrodes, a researcher recorded nerve signals in four neurons in the brain of a snail, called A, B, C, and D in the table below. A, B, and C can all transmit signals to D. In three experiments, the animal was stimulated in different ways. The number of nerve signals transmitted per second by each of the cells is recorded in the table. Write a short paragraph explaining the different results of the three experiments.

Data from E. R. Kandel and L. Tauc, Input organization of two symmetrical giant cells in the snail brain, Journal of Physiology 183: 269–86 (1966).