Roflumilast and TMS Motor Plasticity

Repetitive transcranial magnetic stimulation (rTMS) uses a magnetic field to non-invasively induce electrical function within the brain. Stimulation allows brain cells to change the way that they adapt and communicate with each other, known as 'synaptic plasticity'. It is thought that alterations in these adaptive brain changes underlie the ability of rTMS to treat mental illnesses like depression. The regulation of synaptic plasticity is complex, and involves multiple interacting factors and redundant systems to ensure that plasticity is carefully regulated. To date, studies attempting to alter impact synaptic plasticity have done so using pharmacological adjuncts that target extracellular contributions to plasticity. Here, we propose the first proof of principle study targeting intracellular regulation of plasticity by using a pharmacological adjunct targeting Phosphodiesterase 4 (PDE4), a key regulator a cyclic AMP gradients in brain cells. We will pair TMS with electromyography (EMG) to measure activity dependent changes in the motor cortex following rTMS to test the ability of a PDE4 inhibition to enhance synaptic plasticity after rTMS.