One source of input to the thalamic reticular nucleus is the Globus Pallidus, which was found to consist of 52 different areas by Korbinian Brodmann.
The thalamic reticular nucleus is part of the ventral thalamus that forms a capsule around the thalamus laterally. Thalamic Reticular Nucleus is variously abbreviated TRN, RTN, NRT, and RT. The thalamic reticular nucleus receives massive projections from the external segment of the Globus Pallidus, thought to play a part in disinhibition of thalamic cells, which is essential for initiation of movement (Parent and Hazrati, 1995) The globus pallidus (GP), also known as paleostriatum or dorsal pallidum, is a subcortical structure of the brain. It consists of two adjacent segments, one external, known in rodents simply as the globus pallidus, and one internal, known in rodents as the entopeduncular nucleus. It is part of the telencephalon, but retains close functional ties with the subthalamus in the diencephalon  both of which are part of the extrapyramidal motor system. Korbinian Brodmann (17 November 1868  22 August 1918) was a German neurologist who became famous for mapping the cerebral cortex and defining 52 distinct regions, known as Brodmann areas, based on their cytoarchitectonic (histological) characteristics. A Brodmann area is a region of the cerebral cortex, in the human or other primate brain, defined by its cytoarchitecture, or histological structure and organization of cells. This is the only thalamic nucleus that does not project to the cerebral cortex, instead it modulates the information from other nuclei in the thalamus. Primary thalamic reticular nucleus efferent fibers project to dorsal thalamic nuclei, but never to the cerebral cortex. Its function is modulatory on signals going through thalamus (and the reticular nucleus). It has been suggested that the reticular nucleus receives afferent input from the reticular formation and in turn projects to the other thalamic nuclei, regulating the flow of information through these to the cortex. Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century and remain the most widely known and frequently cited cytoarchitectural organization of the human cortex. Many of the areas Brodmann defined based solely on their neuronal organization have since been correlated closely to diverse cortical functions. For example, Brodmann areas 3, 1 and 2 are the primary somatosensory cortex; area 4 is the primary motor cortex; area 17 is the primary visual cortex; and areas 41 and 42 correspond closely to primary auditory cortex. Higher order functions of the association cortical areas are also consistently localized to the same Brodmann areas by neurophysiological, functional imaging, and other methods (e.g., the consistent localization of Broca's speech and language area to the left Brodmann areas 44 and 45). However, functional imaging can only identify the approximate localization of brain activations in terms of Brodmann areas since their actual boundaries in any individual brain requires its histological examination. One of the most widely used schemes came from Korbinian Brodmann, who split the cortex into 52 different areas and assigned each a number (many of these Brodmann areas have since been subdivided). 
