Disconnection of the Entorhinal Cortex and Dorsomedial Striatum Impairs the Sensitivity to Instrumental Contingency Degradation

Abstract

The capacity to detect changes in the causal efficacy of actions is mediated by a number of brain areas, including the entorhinal cortex (EC) and the posterior part of the dorsomedial striatum (pDMS). In this study we examined whether interactions between the EC and pDMS are required to detect changes in the instrumental contingency. Rats that received EC-pDMS disconnection lesions, that is, unilateral cell body lesions of the EC and contralateral dopamine depletions of the pDMS, were trained to press two levers, with one delivering food pellets and the other a sucrose solution. Thereafter, we tested whether rats were sensitive (1) to a selective devaluation of the value of one of two outcomes using a specific satiety procedure, and (2) to a selective degradation of one of two contingencies controlling instrumental choice behavior. Our results reveal that rats with EC-pDMS disconnection lesions were sensitive to outcome devaluation. However, unlike rats with sham lesions or unilateral EC and pDMS lesions, rats with EC-pDMS disconnection lesions showed a reduced sensitivity to contingency degradation. These findings suggest that EC and pDMS may be part of a neural system that supports the detection of changes in the causal relationship between an action and its consequences.

K-ATP channels in dopamine substantia nigra neurons control bursting and novelty-induced exploration

“…Selective depletion experiments in the DMS revealed that DA release in this striatal region is important for responding to contextual changes in goal-directed behavioral strategies 40 . This is consistent with the strong input to DMS from the entorhinal cortex 41 , which reads out a hippocampal spatial novelty signal 42 .…”

The role of dopamine in the dorsomedial striatum in general and outcome-selective Pavlovian-instrumental transfer

“…, 2005). In addition, our observation that rats subjected to 6‐OHDA infusions had a near complete and circumscribed striatal DA depletion is consistent with our previous studies using the intra‐pDMS infusions of the same dose/volume of 6‐OHDA (Calaminus & Hauber, 2009; Lex & Hauber, 2010a,b). Likewise, an intra‐striatal infusion of a lower dose of 6‐OHDA than used here profoundly reduced tissue concentrations of DA (> 85%; e.g.…”

Habitual alcohol seeking: Modeling the transition from casual drinking to addiction

“…For example, at least two separate groups have reported instances in which animals were differentially sensitive to outcome devaluation and contingency degradation (Corbit, et al, 2002; Lex & Hauber, 2010a; Lex & Hauber, 2010b). In these instances, animals remained sensitive to outcome devaluation, and appeared goal-directed in this measure, but were insensitive to the degradation of the action-outcome relationship.…”