centromedianparafascicular

The centromedian-parafascicular complex, often abbreviated as CM-Pf, refers to two closely related intralaminar nuclei of the thalamus: the centromedian nucleus (CM) and the parafascicular nucleus (Pf). These nuclei form a central hub within the intralaminar thalamic system and lie near the center of the thalamus, overlapping the internal medullary lamina. The CM-Pf receives diffuse input from brainstem arousal systems and other subcortical structures, and it sends widespread projections to cortical and subcortical regions.

Anatomy and connections: The CM and Pf receive ascending inputs from the reticular formation and related brainstem networks, and they integrate information across sensory, motor, and limbic domains. They project broadly to the cerebral cortex, including prefrontal, cingulate, sensorimotor, and insular areas, as well as to several subcortical structures such as the striatum (caudate and putamen) and other components of the basal ganglia. These thalamic nuclei participate in cortico-basal ganglia-thalamo-cortical loops that underlie attention, arousal, and action selection.

Functions: The CM-Pf complex is implicated in arousal and alertness, attention and cue processing, and the modulation of cortical activity during behavioral state changes. It supports sensorimotor integration and higher-order cognitive functions by coordinating activity between the cortex and basal ganglia networks.

Clinical significance: The CM-Pf complex has been investigated as a target for deep brain stimulation in movement disorders such as Tourette syndrome and dystonia, with ongoing research into its potential for other conditions. Disruption of CM-Pf signaling can affect arousal, attention, and motor control, reflecting its role in widespread thalamocortical circuits.