Local Field Potentials of Hippocampus under Urethane-chloralose Anesthesia in Piglets

Abstract

The pig hippocampus has a highly laminated dentate hilus, which clearly resemble to that of primates. However, few studies have been performed to investigate its neural activities. Therefore, in this study we examined local field potentials (LFPs) in the hippocampus of male Landrace piglets under general anesthesia. The anesthesia was maintained by halothane (1-2%) or by intravenous administration of urethane and chloralose with the minimal level of halothane (0.5%). A few spike-shaped waves in the LFPs were found in the hippocampus of the five piglets anesthetized with halothane. In contrast, spike-shaped waves in the LFPs were observed frequently in the three animals anesthetized with urethane and chloralose. Thus, the present study indicates that more spiking activities can be obtained in the hippocampus of the piglets anesthetized by with urethane-chloralose than by halothane. This suggests that the hippocampal neurons are more excitable in the piglets anesthetized with urethane and chloralose than with halothane only. [J Physiol Sci. 2006;56 Suppl:S192]