microzone

(noun)

A group of Purkinje cells that all have the same somatotopic receptive field. Microzones contain on the order of 1,000 Purkinje cells each, arranged in a long, narrow strip, and oriented perpendicular to the cortical folds.

Related Terms

Examples of microzone in the following topics:

  • Functions of the Cerebellum in Integrating Movements

    • Because of the way that they are lined up longitudinally, the 1,000 or so Purkinje cells belonging to a microzone may receive input from as many as 100 million parallel fibers and focus their own output down to a group of less than 50 deep nuclear cells.
    • This schematic illustration of the structure of zones and microzones in the cerebellum shows three levels of magnification.
    • These zones and microzones help explain the modular nature of the cerebellar function.
    • A zone is a longitudinally oriented strip of the cortex, and a microzone is a thin, longitudinally oriented portion of a zone.
    • As the illustration on the right shows, Purkinje cell dendritic trees are flattened in a way that aligns with the microzone length, and parallel fibers cross the microzones at right angles.

  • Functions of the Cerebellum

    • Due to their longitudinal alignment, the approximately 1000 Purkinje cells belonging to a microzone may receive input via neural convergence from as many as 100 million parallel fibers.
    • A module consists of a small cluster of neurons in the inferior olivary nucleus, a set of long narrow strips of Purkinje cells in the cerebellar cortex (microzones), and a small cluster of neurons in one of the deep cerebellar nuclei.

  • Modulation of Movement by the Cerebellum

    • Divergence and convergence: The 1000 or so Purkinje cells belonging to a microzone may receive input from as many as 100 million parallel fibers, and focus their own output down to a group of less than 50 deep nuclear cells.