Advanced progress of vestibular compensation in vestibular neural networks

Vestibular compensation is the natural process of recovery that occurs with acute peripheral vestibular lesion. Here, we summarize the current understanding of the mechanisms underlying vestibular compensation, focusing on the role of the medial vestibular nucleus (MVN), the central hub of the vestibular system, and its associated neural networks. The disruption of neural activity balance between the bilateral MVNs underlies the vestibular symptoms after unilateral vestibular damage, and this balance disruption can be partially reversed by the mutual inhibitory projections between the bilateral MVNs, and their top‐down regulation by other brain regions via different neurotransmitters. However, the detailed mechanism of how MVN is involved in vestibular compensation and regulated remains largely unknown. A deeper understanding of the vestibular neural network and the neurotransmitter systems involved in vestibular compensation holds promise for improving treatment outcomes and developing more effective interventions for vestibular disorders. The mechanism of vestibular compensation.11 The MVN receive afferent signals from the peripheral vestibular system and other brain regions, such as the cerebellum, the neuronal activity is balanced between the bilateral vestibular nuclei. After the unilateral peripheral injury, this loss of afferent leads to down‐regulation of neuronal activity in the ipsilateral vestibular nucleus, while up‐regulation in the contralateral side. This imbalance is believed leading to the symptoms of vestibular disorders. CNS can partially rebalance the neural activity between bilateral MVN, and reverse the vestibular symptoms. In contrast to the ipsilateral side, the contralateral MVN neurons become more active, which might be due to the reduced inhibitory input from the ipsilateral vestibular nucleus. Besides the inhibitory commissural projections between the bilateral MVN, the cerebellum and other brain region inputs are also critical for vestibular compensation. Green dashed line with arrowheads: Excitatory transmission; Brown dashed line with arrowheads: Inhibitory transmission. CNS, Central nervous system; MVN, Medial Vestibular Nucleus.