What Is the Inferior Cerebellar Peduncle?

A fiber tract known as the inferior cerebellar peduncle helps to link the brain structure called the cerebellum to other parts of the nervous system. This is located toward the back of the brain and has several functions, including assisting coordinating movement and determining where the body is located into space. In order to execute these functions properly, the cerebellum must be connected to many areas, including the brain stem. Cerebellar peduncles help to accomplish this connection.

Three groups of connective fibers comprise the cerebellar peduncles. Lowest among them is the inferior cerebellar peduncle, which joins the cerebellum to the medulla and the spinal cord. It also connects the cerebellum to structures near the medulla, like the reticular formation and the vestibular nuclei, which are both found on the brain stem. This fiber tract is found just below the fourth ventricle, a fluid-filled area that cushions the brain, and the roots of two important cranial nerves, the glossopharyngeal and vagus nerves.

Several functions are assisted by the inferior cerebellar peduncle. These functions are predicted by the structures that this tract joins. Cells of the vestibular nuclei are involved in locating the body's sense of balance. By joining this nuclei to the cerebellum, the inferior cerebellar peduncle helps to coordinate motor movements with the current balance of the body.

This particular tract of fibers assists in delivering information about proprioception to the brain, which is a sense that allows the body to know its position in space. Sensory cells known as dorsal root ganglia detect the spatial position of the body, and in particular, the arms and legs. Information from the dorsal root ganglia is sent to other nervous system cells called neurons, located in the spinal cord, and routed to the cerebellum through the inferior cerebellar peduncle. Integrating movement with the body's spatial position is therefore possible due to this cerebellar peduncle.

Some messages from the cerebellum back to the brain stem are sent through this system of fibers. Purkinje cells, a special type of inhibitory cell found in this brain structure, transmit information back to the brain stem through the inferior cerebellar peduncle. Inhibitory signals carried through this tract may combine with motor movement signals from the motor cortex. Motor cortex signals instruct the body to make certain motions, and the information from the cerebellum may assist in fine-tuning these signals and allowing the body to make very precise, exact movements.