| Accessory cuneate nucleus | |
|---|---|
 Section of the medulla oblongata at about the middle of the olive. (Accessory cuneate nucleus is not labeled, butcuneate nucleus is labeled at upper right, and the accessory cuneate nucleus would be found lateral to it.) | |
| Details | |
| Part of | Medulla oblongata |
| Identifiers | |
| Latin | nucleus cuneatus accessorius |
| NeuroNames | 768 |
| NeuroLex ID | birnlex_2634 |
| TA98 | A14.1.04.209 |
| TA2 | 6000 |
| FMA | 72603 |
| Anatomical terms of neuroanatomy | |
Theaccessory cuneate nucleus (alsolateral cuneate nucleus, orexternal cuneate nucleus[1]: 431 ) is anucleus situated in the caudalmedulla oblongata just lateral to thecuneate nucleus. It relays unconsciousproprioceptive sensory information from the upper limb and upper trunk to the cerebellum via thecuneocerebellar fibers.[2]
The neurons of the ACN (as well as those of the lateral portion of the cuneate nucleus) are functionally homologous with theposterior thoracic nucleus; the cuneocerebellar fibers are therefore the upper body functional equivalent of thedorsal spinocerebellar tract.[1]: 432
Synapses in the ACN aresomatotopically organized.[1]: 445
Afferents of the ACN arise from musclestretch receptors and skintouch receptors of the upper limb; they enter the spinal cord rostral to theposterior thoracic nucleus to ascend in the lateral portion of thecuneate fasciculus.[1]: 445 A minority of the fibers of thecuneate fasciculus thus synapse in the ACN.[1]: 431
Efferents of the ACN form thecuneocerebellar fibers that pass through the ipsilateralrestiform body of theinferior cerebellar peduncle to terminate in the ipsilateral hemisphere of the cerebellum;[2] a few of its efferents do not join the cuneocerebellar fibers, instead ascending in the contralateralmedial lemniscus to terminate in thethalamus.[1]: 445
