The D2/D3-receptor antagonist tiapride impairs concurrent but not sequential taste aversion learning

Taste aversion learning (TAL) is a learning modality in which the animals reject a gustatory stimulus associated with the administration of noxious visceral substances. This learning can be established by concurrent or sequential procedures that involve different anatomical and functional mechanisms and may constitute distinct learning modalities. The dopaminergic system has been related to various learning processes and goal-directed behaviours. The present study examined the effect of the administration of tiapride, a D2/D3 dopaminergic antagonist, on concurrent and sequential TAL. Results obtained showed that pre-treatment with tiapride blocks the acquisition of concurrent TAL but does not affect sequential TAL, including reversal learning tasks. These results demonstrate the involvement of the D2/D3 dopaminergic receptors in the former but not the latter learning process. The dopaminergic system appears to participate in concurrent TAL, an “implicit” learning modality, but not in sequential TAL, which is considered a relational/explicit acquisition process.

► Tiapride, a D2/D3 receptor antagonist, impairs concurrent TAL, an implicit learning.
► Tiapride does not interrupt sequential TAL, a relational/explicit learning process.
► Tiapride do not interfere with learning motor flexibility.
► Tiapride is not involved in reversal sequential tasks.
► Concurrent and sequential TAL may depend on different anatomical and neurochemical systems.