Synaptic Receptors in the Cerebellar Cortex
The cerebellum (Latin for “little brain”) is a highly convoluted structure that lies at the level of the pons on the posterior aspect of the brainstem. It has long been associated with motor activity, and is believed to fine-tune muscle action associated with both posture and equilibrium. In addition, it is now thought to contribute to cognitive and emotional activity. Anatomically, the cerebellum contains a well-defined outer cortex plus a distinct set of deeply-embedded neuron cell bodies that form the deep cerebellar nuclei. The cerebellar cortex is composed of three layers: the superficial molecular layer, the Purkinje cell layer, and the granular layer.
In general, extracerebellar neurons project axons, termed mossy and climbing fibers, to both the cerebellar cortex and deep cerebellar nuclei. In the cortex, mossy fibers synapse on granule cells, which subsequently project to Purkinje cells, the dominant cell type in the region. Climbing fibers, by contrast, project directly to Purkinje cells. Purkinje cells are strictly GABAergic, and provide inhibitory output to neurons of the deep cerebellar nuclei. The deep cerebellar nuclei represent the only output structure of the cerebellum. Efferent axons from cerebellar nuclei neurons transmit inhibitory signals to the inferior olive and excitatory output to the brainstem and thalamus. Although the multiple inputs and outputs of the cerebellum are well-defined, the physiological significance and functional relevance of these microcircuits remains to be established. R&D Systems currently offers antibodies to all labeled molecules.