https://phys.org/news/2018-10-behavior-scents-action.html

In a new study published in PLoS Biology, scientists at Université de Montréal, in Quebec, and the University of Windsor, in Ontario, show that an inhibitory circuit that releases the neurotransmitter GABA into the olfactory bulb strongly modulates behaviouralresponses to odours in lampreys. The study of these modulatory mechanisms allowed the researchers to discover a new pathway linking together olfactory and motor centers in the brain. 

This discovery demonstrates that odourscan activate locomotor centers via two distinct brain pathways," said lead author Gheylen Daghfous, a researcher in the laboratory of UdeM neuroscience associate professor Réjean Dubuc, also a professor at Université du Québec à Montréal. "This work shed snew light on the evolution of the olfactory systems in vertebrates."