Dorsolateral Pontine Tegmentum and the Classically Conditioned Nictitating Membrane Response: Analysis of CR-Related Single-Unit Activity

摘要

The classically conditioned nictitating membrane (NM) response in rabbit has been widely adopted for studying learning at both behavioral and physiological levels (Farley and Alkon 1985; Gormezano et al. 1983; Moore 1979; Thompson et al. 1976). Recent evidence indicates that the cerebellum and related structures are critically involved in the control of this behavior (e.g., McCormick et al. 1981; Yeo et al. 1985a). However, a second system, involving reticular formation in the dorsolateral pontine brain stem (DLP), including the supratrigeminal region (SR) (Desmond and Moore 1983), may also participate in the control of CRs (e.g., Desmond and Moore 1982). To date, there is no evidence of direct connections between the DLP/SR and components of the cerebellar circuit, and DLP/SR might therefore be a circuit that is separate from the cerebellar circuit but is nonetheless also essential for the NM CR. Previous investigations have suggested that the dorsolateral pontine tegmentum (DLP) may be part of a system essential for classical conditioning of the nictitating membrane response. The present study examined CR-related firing patterns of extracellularly-recorded single units in the DLP. Differential conditioning, using tonal CSs and periocular electrostimulation as the US, was employed so that firing patterns on CR and non-CR trials could be compared. In light of evidence indicating that the cerebellum is critically involved in conditioning-cerebellum and the DLP, may be in control of CRs. The relationship of the two systems and their possible roles in conditioning are discussed. Keywords: Reprints.