Moss threads

Neurofibra muscoidea

Mossy fibers

The thread type derives its name from its richly branched, often intertwined, end parts fitted with complex grape bunch-like end ends (moss thread rosettes). The appearance of the end parts, after silver staining, in light microscopes has been described as "moss-like", which gives the wire type its name.

The moss threads constitute the dominant thread inflow to the cerebellum and to a small extent also originate inside the cerebellum itself. The threads are excitatory with glutamate as the transmitter substance.

The moss filaments are axons that start from nerve cell groups in:
1/ Spinal cord (nucleus dorsalis and border cells and interneuron in intermediate gray matter of the spinal cord)
2/ The brainstem (nucleus cuneatus lateralis, pons nuclei, balance nuclei, balance ganglia, nuclei in formatio reticularis which convey information from the four-mound plate /sight and hearing/)
3/ Cerebellar nuclei 4/ Cerebellar cortex (unipolar brush cells in the grain cell layer)

The moss wire saxons from 1/ and 2/ above divide into two main stems (Y-shaped) as they reach into the cerebellum.
One main stem enters one of the cerebellar nuclei and directly and excitatorily affects the outflow of signals from the cerebellum.
The second main trunk produces several branches that are distributed in both hemispheres, dividing again into swarms of final branches that find their way into the granular cortex layer of the cerebellar cortex. The swarms group together in dressings below the shallower Purkinje cell joints (see Cerebellum,5.). Here, basal Golgi cell dendrites, unipolar brush cells and, above all, a large number of grain cellsdendrites are contacted.

Here in the cerebellar cortex, with the Purkinje cells as a common target, moss wire information, mediated by grain cell axons, and climbing wireinformation from the lower olive kernel complex will be fused into different, in time extended, movement programs and the ability to detect and lightning quickly adapt the small brain's signal outflow to sudden and unexpected deviations (eng. = errors) from the rolling motion program.

Contact with the grain cell dendrites is complicated. A moss filament rosette, together with the Golgicellend end and up to a score of grain cell dendrites, forms a synaptic skein. The ball is surrounded by a glial capsuleand is called a cerebellar glomerulus. A single moss thread activates a very large number of grain cells spread over large areas within both hemispheres of the cerebellum. The barley cells, in turn, activate long rows of Purkinje cells that inhibitory affect the cerebellar nuclei.