intralaminaarisiin

The intralaminar nuclei are a group of thalamic nuclei located within the thalamus, specifically embedded in the region around the internal medullary lamina. The most prominent components are the centromedian nucleus (CM) and the parafascicular nucleus (Pf), with other adjacent nuclei sometimes associated as part of the intralaminar complex. Together they form a diffuse, interconnected set that participates in broad thalamic networks.

Anatomically, the intralaminar nuclei receive inputs from brainstem arousal systems and various subcortical sources, and they project to widespread cortical areas as well as to subcortical structures. They send thalamocortical projections to multiple association and sensorimotor cortices and also provide thalamostriatal inputs to the striatum, linking thalamic activity to basal ganglia circuits. This dual connectivity places the intralaminar nuclei in a key position to influence cortical processing, motor planning, and action selection.

Functionally, the intralaminar nuclei are implicated in maintaining arousal and attention, coordinating cortical activity across distributed networks, and modulating sensorimotor integration. Their diffuse corticothalamic and thalamostriatal connections support roles in cognitive control, vigilance, and the preparation and execution of movements. They are also involved in certain pain processing pathways and have been studied in the context of learning and adaptive behavior.

Clinical relevance includes associations between intralaminar dysfunction and altered arousal or attention states. In movement and neuropsychiatric disorders, the centromedian–parafascicular complex has been explored as a target for neuromodulation, such as deep brain stimulation, to influence motor symptoms and cognitive aspects of disease.