Swimmer Dimmer (IMAGE) Society for Neuroscience Caption Stimulation of the posterior tuberculum (PT) of the lamprey forebrain gradually activates neurons in the mesencephalic locomotor region (MLR) of the brainstem, which in turn ramps up swimming frequency like a dimmer switch. Credit Ryczko et al., The Journal of Neuroscience (2017) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.