Cell nucleus
Cell nuclei contain most of the cell's genetic material, organized as multiple long linear DNA molecules in a complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome and are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression—the nucleus is, therefore, the control center of the cell. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm, and the nuclear matrix (which includes the nuclear lamina), a network within the nucleus that adds mechanical support, much like the cytoskeleton, which supports the cell as a whole.
Claustrum
The claustrum is made up of various cell types differing in size, shape and neurochemical composition. Five cell types exist and a majority of these cells resemble pyramidal neurons found in the cortex Within the claustrum, there is no organization of cell types compared to the cortex and the somas of the cells can be a pyramidal, fusiform or circular shape. The principal cell type found in the claustrum is Type 1 cells, which are large cells covered in spiny dendrites.