Fronto‐parietal and temporal brain dysfunction in depression: A fMRI investigation of auditory mismatch processing

Abstract

Mismatch responses reflect neural mechanisms of early cognitive processing in the auditory domain. Disturbances of these mechanisms on multiple levels of neural processing may contribute to clinical symptoms in major depression (MD). A functional magnetic resonance imaging (fMRI) study was conducted to identify neurobiological foundations of altered mismatch processing in MD. Twenty‐five patients with major depression and 25 matched healthy individuals completed an auditory mismatch paradigm optimized for fMRI. Brain activity during mismatch processing was compared between groups. Moreover, seed‐based connectivity analyses investigated depression‐specific brain networks. In patients, mismatch processing was associated with reduced activation in the right auditory cortex as well as in a fronto‐parietal attention network. Moreover, functional coupling between the right auditory cortex and frontal areas was reduced in patients. Seed‐to voxel analysis on the whole‐brain level revealed reduced connectivity between the auditory cortex and the thalamus as well as posterior cingulate. The present study indicates deficits in sensory processing on the level of the auditory cortex in depression. Hyposensitivity in a fronto‐parietal network presumably reflects altered attention mechanisms in depression. The observed impairments may contribute to psychopathology by reducing the ability of the affected individuals to orient attention toward important environmental cues.

Chronic Fluoxetine Treatment Induces Maturation-Compatible Changes in the Dendritic Arbor and in Synaptic Responses in the Auditory Cortex

“…In patients, it has been shown that auditory cortex activation and auditory perception and processing are impaired in depression (Zwanzger et al, 2012; Bonetti et al, 2017; Zweerings et al, 2019). Moreover, age-related hearing loss has been associated with late life depression (Husain et al, 2014; Rutherford et al, 2018; Scinicariello et al, 2019), and in animals, chronic restraint stress decreased glucose metabolism in the auditory cortex (Wei et al, 2018).…”

“…Considering the widespread increase in GluN2A subunits following fluoxetine, we examined structural and synaptic adaptations in cortical areas that are not directly involved in the modulation of mood, such as sensory (including auditory) and motor cortices, which are impaired in depression and might be affected by fluoxetine treatment (Zwanzger et al, 2012; Frodl, 2017; Yin et al, 2018). We specifically evaluated the dendritic architecture and the synaptic properties of pyramidal neurons in the auditory cortex after fluoxetine treatment, an area that is disturbed in depression (Zweerings et al, 2019). Our results indicate that fluoxetine induces structural and functional adaptations compatible with increased network maturation.…”

Aberrant levels of cortical myelin distinguish individuals with unipolar depression from healthy controls

“…In contrast, participants with UD had greater myelin in 6 visual regions and had reduced myelin in 3 regions (left V4t, left FFC, and left 7AL). While depression is not typically considered a disorder of dysfunctional sensory processing, somatic symptoms in depression have been well described 65 , and there are reports of both visual 66 and auditory 67 processing deficits in depression. Our results contribute to a growing body of literature documenting associations of depression with altered structure 12 and functional connectivity 68,69 in sensory regions.…”

The effectiveness of a virtual reality attention task to predict depression and anxiety in comparison with current clinical measures

“…Currently, the nature of attention deficits in depression and anxiety, especially in relation to sensory processing, is still lacking. Most research in anxiety and depression has focused on early pre-attentive and automatic visual and auditory processing and showed impaired deficits in early auditory and visual processing in depressed and anxious samples (Chang et al 2011;Kahkonen et al 2007;Qiu et al 2011;Schirmer and Escoffier 2010;Takei et al 2009;Weinstein 1995;Yang et al 2019;Zweerings et al 2019). However, sensory processing as modulated by attention has not been studied in depression and anxiety, which we plan to address in the current study by exploring attention performance on auditory and visual stimuli of individuals with elevated symptoms of depression and anxiety in comparison with individuals with low symptoms.…”