The brain peduncles are two stalks that attach the brain to the brain .  They are structures in the front of the midbrain that arise from the ventral pons and contain large ascending (sensory) and descending (motor) nerve pathways that run from the pons to the brain . Mainly, the three general regions that give rise to the cerebral peduncles are the cerebral cortex , the spinal cord , and the cerebellum. The cerebral peduncle is, according to most classifications, everything in the midbrain .except textum . Areas included tegmentum , shank cerebrum and pretectum . According to this definition, the cerebral peduncle is also known as the base pedunculi , while the larger ventral bundle of efferent fibers is called the cerebral crus or pes pedunculi .
The cerebral peduncles are located on either side of the midbrain and are the frontmost part of the midbrain, and act as connectors between the rest of the midbrain and the thalamic nuclei and thus the brain . Overall, cerebral peduncles assist in refining motor movements, learning new motor skills, and converting proprioceptive information into balance and posture maintenance.   Important fiber tracts running through the cerebral peduncles are the corticospinal , corticopontine , and corticobulbar tracts . damage to the cerebral peduncles may lead to poor motor skills, imbalance andOccurs as a result of a lack of proprioception .
Descending upper fibers from the internal capsule continue through the midbrain and are then seen as fibers in the cerebral peduncles.  Corticopontine fibers found in the outer and inner third of the cerebral peduncle are cortical inputs to the pontine nucleus.  Corticobulbar and corticospinal fibers are found in the middle third of the cerebral peduncle.  The corticospinal tract exits the internal capsule and is seen in the central part of the cerebral peduncles.
The cranial nerve 3 (oculomotor nerve) appears ventral between two cerebral peduncles in the interpeduncular fossa. Cranial nerve 4 (trochlear nerve) wraps around the lowest part of the cerebral peduncle.