NeuroNames hier-495 TA A14.1.06.336 | Dorlands/Elsevier n_11/12583626 | |
Latin nucleus tegmentalis pedunculopontinus MeSH Pedunculopontine+Tegmental+Nucleus NeuroLex ID Pedunculopontine tegmental nucleus | ||
The pedunculopontine nucleus (PPN) (or pedunculopontine tegmental nucleus, PPTN or PPTg) is located in the brainstem, caudal to the substantia nigra and adjacent to the superior cerebellar peduncle. It has two divisions, one containing cholinergic neurons, the pars compacta, and one containing mostly glutamatergic neurons, the pars dissipata. The PPN is one of the main components of the reticular activating system. It was first described in 1909 by Louis Jacobsohn-Lask, a neuroanatomist born in Bydgoszcz.
Contents
Projections
PPN neurons project axons to a wide range of areas in the brain, particularly parts of the basal ganglia such as the subthalamic nucleus, substantia nigra pars compacta, and globus pallidus internus. It also sends them to targets in the thalamus, cerebellum, basal forebrain, and lower brainstem, and in the cerebral cortex, the supplementary motor area and somatosensory and motor cortices.
It receives inputs from many areas of the brain, including the basal ganglia to which it projects with the exception of the substantia nigra pars compacta to which it projects but does not receive, while it receives but does not project to the substantia nigra pars reticulata.
Functions
The PPN is involved in many functions, including arousal, attention, learning, reward, and voluntary limb movements and locomotion. While once thought important to the initiation of movement, recent research suggests a role in providing sensory feedback to the cerebral cortex. It is also implicated in the generation and maintenance of REM sleep.
Recent research has discovered that the PPN is involved in the planning of movement, and that different networks of neurons in the PPN are switched on during real and imagined movement.
Parkinson disease
Research is being done on whether deep brain stimulation of the PPN might be used to improve the gait and postural difficulties found in Parkinson disease.