Intralaminar Thalamic Nuclei: Cell groups within the internal medullary lamina of the THALAMUS. They include a rostral division comprising the paracentral, central lateral, central dorsal, and central medial nuclei, and a caudal division composed of the centromedian and parafascicular nuclei.Thalamic Nuclei: Several groups of nuclei in the thalamus that serve as the major relay centers for sensory impulses in the brain.Midline Thalamic Nuclei: Small, nonspecific nerve cells scattered in the periventricular GRAY MATTER, separating the medial part of the thalamus from the EPENDYMA of the THIRD VENTRICLE. The group includes the paraventricular nucleus, paratenial nucleus, reuniens nucleus, rhomboidal nucleus, and subfascular nucleus.Thalamus: Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.Posterior Thalamic Nuclei: A transitional diencephalic zone of the thalamus consisting of complex and varied cells lying caudal to the VENTRAL POSTEROLATERAL NUCLEUS, medial to the rostral part of the PULVINAR, and dorsal to the MEDIAL GENICULATE BODY. It contains the limitans, posterior, suprageniculate, and submedial nuclei.Anterior Thalamic Nuclei: Three nuclei located beneath the dorsal surface of the most rostral part of the thalamus. The group includes the anterodorsal nucleus, anteromedial nucleus, and anteroventral nucleus. All receive connections from the MAMILLARY BODY and BRAIN FORNIX, and project fibers to the CINGULATE BODY.Mediodorsal Thalamic Nucleus: The largest of the medial nuclei of the thalamus. It makes extensive connections with most of the other thalamic nuclei.Ventral Thalamic Nuclei: A large group of nuclei lying between the internal medullary lamina and the INTERNAL CAPSULE. It includes the ventral anterior, ventral lateral, and ventral posterior nuclei.Neural Pathways: Neural tracts connecting one part of the nervous system with another.