Methods for repeated recording in visual cortex of anesthetized and awake behaving infant monkeys

This report describes methods for making repeated recordings from visual cortex in infant macaque monkeys (age range 5 weeks to 7 months) both under nitrous oxide anesthesia and in an alert behaving state. These methods permitted successful collection of single-unit data from inferior temporal cortex and other areas in a longitudinal fashion from individual infants. For the anesthetized experiments, modifications of our standard techniques for surgical preparation and maintenance of the animal in an anesthetized, artificially ventilated state permitted repeated recording sessions while assuring the animal's continued health and normal growth. Following implantation with an eye coil, monkeys as young as 5 weeks could be trained to perform a fixation task during alert recording sessions which were likewise performed on a repeated basis with maintained health and development. Further, comparison of results from anesthetized and awake recording sessions indicates that alert recording is preferable for collecting certain types of data from visual cortex in infant monkeys.