Dysfunctional longitudinal dentate gyrus network in hearing loss-induced anxiety

Anxiety is a characteristic comorbidity of noise-induced hearing loss (NIHL). NIHL causes physiological changes within the dentate gyrus (DG), a subfield of the hippocampus that is known to modulate anxiety. However, it remains unclear which DG circuit underlies hearing loss-induced anxiety. Here, we utilize an NIHL mouse model to investigate short- and long-term synaptic plasticity in DG networks. Animals with NIHL demonstrate increased anxiety-like behaviors which are similar to those observed in response to chronic restraint stress. This behavior is concurrent with enhanced synaptic responsiveness and the suppression of short- and long-term synaptic plasticity in the longitudinal DG-DG network, but not in the transverse DG-CA3 connection. These findings suggest that DG-related diseases can be typified by synaptic alterations of the longitudinal DG-DG network.