Interhemispheric inhibition between motor cortices (IHI)

> **Interhemispheric inhibition between motor cortices** refers to a neurophysiological process in which activation of one hemisphere's primary motor cortex (M1) inhibits the contralateral M1. This phenomenon is primarily mediated by transcallosal pathways through the corpus callosum and can be measured using techniques such as transcranial magnetic stimulation (TMS)[2][4][7]. The process plays an essential role in coordinating bilateral motor activity and maintaining independent processing within each hemisphere. It is not a molecular target but rather describes functional connectivity and inhibitory interactions at the systems neuroscience level. Alterations in interhemispheric inhibition are implicated in various neurological conditions, including stroke recovery—where abnormal IHI may hinder rehabilitation—and movement disorders such as those seen in musicians with dystonia or after brain injury[3][5][9]. While not itself a druggable target, understanding IHI informs therapeutic strategies that use noninvasive brain stimulation to modulate cortical excitability for clinical benefit. **Note:** This entry does *not* correspond to a discrete molecule, receptor, enzyme, transporter, or other canonical drug target class. Instead, it describes a physiological mechanism/process involving neural circuits and synaptic transmission across hemispheres via the corpus callosum. Therefore: * **is_target:** false — Not considered a direct therapeutic/druggable target. * **is_incorrect:** true — The entry does not fit standard definitions for molecular targets; it represents an emergent property of neural networks rather than an individual biomolecule or receptor. If you require information on specific molecules mediating this process—such as GABAergic receptors involved at synapses within these pathways—please specify further so that more granular molecular details can be provided.

Other names

Interhemispheric inhibition (IHI)Transcallosal inhibitionInhibition between primary motor corticesIHI between M1s