Auditory cortical regions show resting-state functional connectivity with the default mode-like network in...

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Mammalian Auditory Systems

Background:

• Echolocating bats are highly social and vocal mammals with specialized auditory and limbic systems.
• Functional MRI (fMRI) studies are ideal for investigating auditory social communication in bats.
• No resting-state networks related to social cognition (default mode-like networks or DMLNs) have been identified in bats previously.

Purpose of the Study:

• To identify resting-state networks in bats using fMRI.
• To investigate neural activity in response to ultrasonic auditory stimuli.
• To explore functional connectivity between auditory/parietal networks and DMLNs in bats.

Main Methods:

• Acquired 7 Tesla fMRI data from nine anesthetized pale spear-nosed bats (Phyllostomus discolor).
• Applied independent components analysis (ICA) to reveal resting-state networks.
• Measured neural activity elicited by ultrasonic noise ripples (20-130 kHz).

Main Results:

• Resting-state networks were found in auditory, parietal, and occipital cortices, hippocampus, cerebellum, basal ganglia, and auditory brainstem.
• Two midline networks formed an apparent DMLN, with four additional auditory/parietal cortical networks (two left-, two right-lateralized).
• Significant functional connectivity was observed between left auditory/parietal networks and DMLN nodes, particularly the anterior cingulate cortex.

Conclusions:

• This study identifies DMLNs in bats, suggesting their role in social cognition.
• Functional connectivity patterns indicate a more distributed role for left hemispheric auditory and communication substrates in bats.
• Findings advance our understanding of social communication and neural networks in highly vocal mammals.