Activation of the dopaminergic pathway from VTA to the medial olfactory tubercle generates odor-preference and reward

Abstract

Odor-preferences are usually influenced by life experiences. However, the neural circuit mechanisms remain unclear. The medial olfactory tubercle (mOT) is involved in both reward and olfaction, whereas the ventral tegmental area (VTA) dopaminergic (DAergic) neurons are considered to be engaged in reward and motivation. Here, we found that the VTA (DAergic)-mOT pathway could be activated by different types of naturalistic rewards as well as odors in DAT-cre mice. Optogenetic activation of the VTA-mOT DAergic fibers was able to elicit preferences for space, location and neutral odor, while pharmacological blockade of the dopamine receptors in the mOT fully prevented the odor-preference formation. Furthermore, inactivation of the mOT- projecting VTA DAergic neurons eliminated the previously formed odor-preference and strongly affected the Go-no go learning efficiency. In summary, our results revealed that the VTA (DAergic)- mOT pathway mediates a variety of naturalistic reward processes and different types of preferences including odor-preference in mice.