Middle-Latency Responses of Awake and Anesthetized Japanese Macaques

Abstract

The middle-latency response (MLR) of two Japanese macaques were investigated. In the awake state, the configuration of the MLR components showed two positive peaks: P_a and P_b. The latency and the configuration of P_a were very similar to those of humans. In the topographic recordings, the largest P_a amplitude was found from the vertex, or R₁, which is 1 cm lateral to the vertex. In the anesthetic state, P_a and P_b gradually disappeared. This study shows that the MLR in awake Japanese macaques is similar to that in humans, and differs from that in cats. Therefore these awake monkeys are suitable as animal models of human MLR.

Key Words:

• Middle latency response (MLR)
• Awake
• Pentobarbital
• Japanese macaques
• Topographic recording