Complex sentence: An important contributor to leptin resistance is changes to leptin receptor signalling, particularly in the arcuate nucleus, however, deficiency of, or major changes to, the leptin receptor itself are not thought to be a major cause.
Split into simpler sentences: An important contributor to leptin resistance is changes to leptin receptor signalling, particularly in the arcuate nucleus. However, deficiency of, or major changes to, the leptin receptor itself are not thought to be a major cause.