Effective active sensing involves adaptive motor control of sensory organs, responding to contextual, sensory, and task-specific demands. This process develops postnatally, influenced by the maturation of intracortical circuits. Disruptions in sensorimotor network connectivity during this developmental period may have lasting effects on sensorimotor computation into adulthood. Serotonin plays a crucial role in developmental network regulation, prompting us to investigate how alterations in serotonergic signaling impact the emergence and maturation of sensorimotor control. Using an object localization task focused on whisker motor dynamics during tactile navigation, our study reveals that sustained changes in serotonergic signaling, observed in serotonin transporter knockout rats or through transient pharmacological inactivation during early postnatal development, hinder the development of adaptive motor control based on recent sensory information. This altered control results in reduced mechanical force transmitted to whisker follicles upon contact, indicating that increased excitability linked to altered serotonergic signaling is not solely due to heightened synaptic drive from the periphery during whisker contact. Our findings emphasize the essential role of intact serotonergic signaling in the postnatal development of adaptive motor control, highlighting how even transient dysregulation in early development leads to enduring sensorimotor impairments in adulthood.
Serotonergic development of active sensing
Alireza Azarfar, Yiping Zhang, Artoghrul Alishbayli, Dirk Schubert, Judith R. Homberg,