Live Holotomography of Growing Serotonergic Axons

Researchers have developed a new method to observe the growth of serotonergic axons in real time, using a technique called high-resolution holotomography (HT). This imaging technique relies on differences in refractive index, and allowed scientists to examine the growth of individual serotonergic axons in mouse embryonic brain tissue.

The growth of serotonergic axons was tracked over both short (seconds) and longer (hours) time scales. By identifying these axons through their Tph2-dependent green fluorescent protein (GFP) expression, researchers were able to capture the process of axons extending along pre-existing neurites, as well as the formation of stable connections and subsequent extension of the axons themselves.

The HT visualization provided detailed insights into the spatiotemporal dynamics of serotonergic growth cones, revealing them as stochastic processes. This method also allowed for the examination of fine intracellular structures within these growth cones.

The study demonstrates the potential of HT in advancing serotonin research, which could have significant implications for neuropharmacology and regenerative medicine. Additionally, the quantitative data generated by this technique can be utilized for computational modeling of the complex network of serotonergic neurotransmission in the brain.