Studies of individual differences as a method for discriminating the stages of acquisition of a conditioned reflex

Abstract

Learning of a two-way active avoidance response in a shuttle box, which reflects the establishment of a complex reflex, was characterized by a high level of individual variability for learning measures. Our previous report (Savonenko and Zelin'ski, 1997) showed that rats with different rates of learning have different parameters for the freezing response, demonstrating that the animals' behavior shows a conflicting drive not to enter into the other half of the box. We analyze here the sequence of freezing, avoidance, and escape responses in groups of rats with different rates of learning. The results support the hypothesis that the need to overcome conflict is a separate stage of learning, occurring before the stage at which the avoidance response forms and stabilizes.

Persistent active avoidance correlates with activity in prelimbic cortex and ventral striatum

“…However, others studies have dissociated fear from avoidance (Lolordo and Rescorla, 1966 ; Riccio and Silvestri, 1973 ; Overmier and Brackbill, 1977 ). The majority of studies focus on neural mechanisms of avoidance acquisition (Gabriel et al, 1983 ; Orona and Gabriel, 1983 ; Gabriel, 1990 ; Maren et al, 1991 ; Savonenko et al, 1999 ; Holahan and White, 2002 ; Lázaro-Muñoz et al, 2010 ; Shumake et al, 2010 ; Darvas et al, 2011 ; Moscarello and LeDoux, 2013 ; Beck et al, 2014 ; Lichtenberg et al, 2014 ; Ramirez et al, 2015 ), but few focus on its extinction (Gabriel et al, 1983 ; Pang et al, 2010 ; Jiao et al, 2011 ; Bravo-Rivera et al, 2014b ; Wendler et al, 2014 ). In a platform-mediated avoidance task (Bravo-Rivera et al, 2014b ), rats learn to avoid a tone-signaled footshock by stepping onto a nearby platform at the expense of sucrose pellets.…”