It is well established that glucocorticoid administration into a variety of brain regions facilitates memory consolidation of fear-conditioning tasks, including inhibitory avoidance. The present findings indicate that the natural glucocorticoid corticosterone administered into the dorsal striatum (i.e., caudate nucleus) of male Wistar rats produced dose-and time-dependent enhancement of inhibitory avoidance memory consolidation. However, as assessed with a modified inhibitory avoidance procedure that took place on two sequential days to separate context training from footshock training, corticosterone administration into the dorsal striatum did not enhance memory of either the contextual or aversively motivational aspects of the task.Considerable evidence indicates that adrenocortical hormones facilitate the consolidation of long-term memories of emotionally arousing experiences by acting in a variety of brain regions (for reviews, see Sandi 1998; de Kloet et al. 1999;Roozendaal 2000;McGaugh and Roozendaal 2002). For example, glucocorticoids administered post-training into either the hippocampus or the basolateral amygdala enhance memory of fear-conditioning tasks, including inhibitory avoidance (Cottrell and Nakajima 1977; Roozendaal and McGaugh 1997a,b). However, recent findings indicate that glucocorticoid infusions into these two brain regions enhance memory consolidation of different aspects of information learned during inhibitory avoidance training. To assess the relative involvement of a brain region in memory consolidation of the contextual information independently from that of the footshock, we have used a modified inhibitory avoidance procedure in which context training alone and footshock training alone occur on two sequential days (Malin and McGaugh 2006). Consistent with extensive evidence that the hippocampus is involved in the learning of contextual information (Maren and Fanselow 1997;Sacchetti et al. 1999), a specific glucocorticoid receptor (GR) agonist administered into the hippocampus after context exposure enhanced the subsequent conditioning whereas infusions administered after the footshock training were ineffective (Roozendaal et al. 2008). In contrast, a GR agonist infused into the basolateral amygdala enhanced retention when administered after either the context or footshock training, consistent with extensive evidence that basolateral amygdala activity modulates memory for many different kinds of experiences (Roozendaal 2000;McGaugh 2004). Similar differential effects have been reported previously with infusions of a muscarinic agonist into these two brain regions (Malin and McGaugh 2006).The dorsal striatum (i.e., caudate nucleus) is also involved in consolidation of inhibitory avoidance training. Since the 1960s, it has been recognized that lesions of the dorsal striatum or pharmacological manipulations of striatal function modulate inhibitory avoidance memory (Kirkby and Kimble 1968;Haycock et al. 1973;Prado-Alcalá et al. 1975, 1980, 2003 Pérez-Ruíz and PradoAlcalá 1989;Chavez et ...