Cellular and Molecular Neurobiology
Author: Lucia Salatino | email: lu.salatin@gmail.com
Lucia Salatino 1°, Ana Belen Elgoyhen 2°, Paola V. Plazas 1°
1° Instituto de Farmacología, Facultad de Medicina, UBA
2° INGEBI, CONICET
Spontaneous electrical activity (SEA) is required for the proper assembly of sensory circuits in early stages of development; however the mechanisms underlying this phenomenon are still unknown. We use the Zebrafish (Danio rerio) lateral line system (zLL) in order to decipher the mechanisms by which SEA affects the assembly of developing sensory circuits. The LL allows fishes and amphibians to detect water motion and pressure changes and consists of clusters of neuromasts, which contains mechanosensory hair cells (HC). zLL HC are innervated by afferent (Aff) and efferent neurons, and share structural, functional and molecular similarities with HC in the vertebrate inner ear. zLL Aff exhibit SEA between 5 and 7 days post-fertilization. In order to silence SEA in single zLL Aff we stochastically over-expressed inward rectifier K+ channels and analyzed the phenotype and the dynamics of axonal arbor growth. Our results indicate that suppression of SEA in single zLL Aff led to a decrease in the innervation area in the hindbrain and affects axonal arbor complexity. Moreover, silenced neurites display higher motility, formation and elimination rates, as well as lower number of synapses than WT ones, which are features of immature neurons. We provide an in vivo demonstration that SEA regulates axonal arbor growth and maturation, in developing zLL Aff.