The field of Neuromodulation is rapidly growing
Modulating the activity of specific brain structures to understand function, but also to manage dysfunction, seems to be a timeless mission of neuroscientists. Classical tools are lesioning, electrical and chemical stimulation.
Although effective at the level of the brain structure, these tools lack a high degree of selectivity and specificity. In the search for more advanced neuromodulation techniques, for instance enabling one to influence only a specific subpopulation of neurons, optogenetic and Designer Receptors Exclusively Activated by Designer Drugs (DREADD) approaches have been introduced.
These tools are now being used in several laboratories. Now another novel approach can be added to this list: magnetothermal neuromodulation (Chen et al, Science, 2015). In a cleverly designed set of experiments, the authors succeeded in exciting a specific population of neurons in the mice ventral tegmental area by remote activation of extracellular magnetic nanoparticles linked to intracellular calcium sensitized to heat. The general principle of neuromodulation is to influence the activity of localized neuronal elements by an external and preferably reversible approach.
The development of remote magnetothermal neuromodulation fits into the Zeitgeist. After a long period of technological downtime (Ineichen et al., 2014), a number of novel clinical approaches have been made public. In the field of DBS, the promising ones are adaptive/closed-loop DBS (Rosin et al., 2011, Cagnan et al., 2014) and current steering (Contarino et al., 2014). For lesional surgery, novel ultrasound-based approaches are receiving interest (Lipsman et al., 2013). Speeding up these developments seems to be linked to the fact that systemic drug based approaches have not delivered the breakthroughs that the field was looking for, mainly in the field of neurodegenerative and psychiatric diseases, which led to a downscaling of CNS drugs activities of major companies (Grill, 2011).