Intracellular receptors that can be found in the cytoplasm or in the nucleus. They bind to extracellular signaling molecules that migrate through or are transported across the cell membrane. Many members of this class of receptors occur in the cytoplasm and are transported to the cell nucleus upon ligand-binding where they signal via dna-binding and transcription regulation. Also included in this category are receptors found on intracellular membranes that act via mechanisms similar to CELL SURFACE RECEPTORS.