Structure of physiologically identified X and Y cells in the cat's lateral geniculate nucleus.

Horseradish peroxidase injected into 18 single, physiologically identified geniculate X and Y cells permitted a detailed morphological correlate to be determined for the physiological properties of each neuron. Class 1 morphological characteristics were associated with Y cells, class 3 with X cells, and class 2 structural traits were seen in both physiological types.