Further Electrochemical and Behavioural Evidence of a Direct Relationship Between Central 5-HT and Cytoskeleton in the Control of Mood

Serotonin 2A receptor regulates microtubule assembly and induces dynamics of dendritic growth cones in rat cortical neurons in vitro

Serotonin (5-HT) regulates the development of cerebral cortex, but 5-HT receptors mediating the effects are poorly understood. We investigated roles of 5-HT2A receptor in dendritic growth cones using dissociation culture of rat cerebral cortex. Neurons at embryonic day 16 were cultured for 4 days and treated with 5-HT2A/2C receptor agonist (DOI) for 4h. DOI increased the size of growth cone periphery which was actin-rich and microtubule-associated protein 2-negative at the dendritic tip. The length increase of the growth cone periphery may be mediated by 5-HT2A receptor, because the 5-HT2A receptor antagonist reversed the effects of DOI. Moreover, the time-lapse analysis demonstrated the increase of morphological dynamics in dendritic growth cones by DOI. Next, to elucidate the mechanisms underlying the actions of 5-HT2A receptor in dendritic growth cones, we examined the cytoskeletal proteins, tyrosinated α-tubulin (Tyr-T; dynamic tubulin) and acetylated α-tubulin (Ace-T; stable tubulin). DOI increased the fluorescence intensity of Tyr-T, while decreased that of Ace-T in the dendritic growth cone periphery. These effects were reversed by the 5-HT2A receptor antagonist, suggesting that 5-HT2A receptor promotes microtubule dynamics. In summary, it was suggested that 5-HT2A receptor induces morphological changes and dynamics of dendritic growth cones through regulation of microtubule assembly.

Novel molecular and nanosensors for in vivo sensing

In vivo sensors are an emerging field with the potential to revolutionize our understanding of basic biology and our treatment of disease. In this review, we highlight recent advances in the fields of in vivo electrochemical, optical, and magnetic resonance biosensors with a focus on recent developments that have been validated in rodent models or human subjects. In addition, we discuss major challenges in the development and translation of in vivo biosensors and present potential solutions to these problems. The field of nanotechnology, in particular, has recently been instrumental in driving the field of in vivo sensors forward. We conclude with a discussion of emerging paradigms and techniques for the development of future biosensors.