“…Because of the overlap between some features of CRs and CRM, a strong neural candidate for CRM acquisition is the interpositus (IP) nucleus of the cerebellum, which is a major site for the integration of CS and US inputs with outputs controlling the generation of the rabbit eyeblink CR (Gonzalez-Joekes and Schreurs, 2012; Gould, Sears, & Steinmetz, 1993; Ostrowska, Zguczynski, & Zimny, 1992; Steinmetz and Sengelaub, 1992; Thompson, 2013). There is general consensus that the IP is necessary for the acquisition of eyeblink conditioning, as indicated by IP lesion and inactivation studies showing severe impairments to CR acquisition and electrophysiological studies demonstrating the development of learning-related neuronal activity in the IP closely associated with the execution of the CR ( for review, see Christian and Thompson, 2003; Freeman and Steinmetz, 2011; but see also Ammann, Marquez-Ruiz, Gomez-Climent, Delgado-Garcia, & Gruart, 2016; López-Ramos, Houdek, Cendelín, Vožeh, & Delgado-García, 2018). Of particular relevance is work showing that CRM-like increases in the amplitude of the UR in well-trained rabbits is blocked or disfacilitated by IP inactivation, suggesting a role of the IP in CRM expression (Wikgren and Korhonen, 2001).…”