The neocerebellum, also known as the cerebrocerebellum, is the most recently evolved part of the cerebellum, and it is involved in the planning and execution of voluntary movements.
The neocerebellum consists of the lateral hemispheres of the cerebellum and the dentate nucleus, which is located in the deep cerebellar nuclei. The lateral hemispheres are the largest part of the cerebellum and are connected to the cerebral cortex via the pontine nuclei, which are located in the brainstem. The pontine nuclei receive input from the cerebral cortex and relay this information to the cerebellum via the middle cerebellar peduncle, a bundle of fibers that connects the cerebellum to the brainstem.
The lateral hemispheres of the neocerebellum are divided into several lobes, including the anterior lobe, the posterior lobe, and the flocculonodular lobe. The anterior lobe is involved in the control of limb movements, while the posterior lobe is involved in the planning and coordination of complex movements, such as those involved in speech, writing, and playing musical instruments. The flocculonodular lobe, which is also part of the archicerebellum, is involved in the regulation of balance and eye movements.
The dentate nucleus, which is located in the deep cerebellar nuclei, receives input from the lateral hemispheres of the neocerebellum and sends output to the thalamus and cerebral cortex via the superior cerebellar peduncle, another bundle of fibers that connects the cerebellum to the brainstem. The dentate nucleus plays a critical role in the control of voluntary movements, and dysfunction of this nucleus can lead to a variety of movement disorders.
Overall, the neocerebellum is involved in the planning and execution of voluntary movements, and it is connected to the cerebral cortex via the pontine nuclei and the thalamus. Dysfunction of the neocerebellum or its connections can lead to a variety of neurological disorders, including ataxia, dysmetria, and dysarthria.