The statement “throughout all grey matter” refers to the distribution of a substance or structure throughout all regions of the grey matter in the central nervous system. Grey matter is the tissue in the brain and spinal cord that is composed mainly of neuronal cell bodies, dendrites, and glial cells.

The distribution of various substances, including neurotransmitters, receptors, and proteins, can vary across different regions of the grey matter. However, substances that are distributed “throughout all grey matter” would be present in a relatively homogeneous and uniform manner across all regions of the grey matter.

For example, the neurotransmitter dopamine is distributed throughout all regions of the grey matter, where it plays important roles in regulating movement, motivation, and reward. Similarly, astrocytes, a type of glial cell that provides support and modulates neuronal activity, are also distributed throughout all regions of the grey matter.

Understanding the distribution of substances and structures throughout the grey matter is important for understanding the complex processes that occur in the central nervous system, including sensory processing, motor control, and higher cognitive functions. Deviations from normal distribution patterns can also provide important insights into the underlying pathology of neurological disorders.