Intralaminar nuclei of thalamus

The intralaminar nuclei of thalamus are a collection of nerve cells which are situated within the internal medullary lamina. They receive neuronal inputs from various pathways, however, the major input arises from the basal ganglia. They have two-way connections with the cerebral cortex.

The intralaminar nuclei of thalamus can be subdivided into caudal and rostral sub-groups:

The caudal intralaminar nuclei of thalamus include parafascicular and centromedian nuclei and have important connections with the basal ganglia (striatum), through which they regulate the activity of caudate nucleus and putamen.

The rostral intralaminar nuclei of thalamus, in addition to having connections with basal ganglia, play a role in relaying neural inputs from the ascending reticular formation and forwarding them to the cerebral cortex, inducing cortical activation. Some even consider these nuclei to be a rostral extension of ascending reticular activating system. The intralaminar induced cortical activation leads to greater vigilance, necessary for awareness of incoming information, thus influencing the level of alertness and consciousness of an individual.