Different Excitation-Inhibition Correlations Between Spontaneous and Tone-evoked Activity in Primary Auditory Cortex...

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Synaptic Plasticity

Background:

• Synaptic excitation and inhibition are correlated in primary auditory cortex neurons during tone presentation.
• Previous studies indicated less correlation between spontaneous excitation and inhibition in the visual cortex.

Purpose of the Study:

• To investigate the correlation between spontaneous excitation and inhibition in the primary auditory cortex.
• To compare spontaneous activity correlation with tone-evoked activity correlation in the auditory cortex.

Main Methods:

• Whole-cell voltage-clamp recordings were performed on primary auditory cortex neurons in anesthetized rats.
• Spontaneous excitatory and inhibitory synaptic currents were measured and analyzed.
• Filtered Poisson process models were used to estimate excitatory-inhibitory correlation.

Main Results:

• Spontaneous excitatory and inhibitory currents in the auditory cortex largely comprised distinct events.
• The inhibitory event rate was typically lower than the excitatory event rate during spontaneous activity.
• Spontaneous activity exhibited a lower excitatory-inhibitory correlation than tone-evoked responses in neurons with V-shaped tuning curves.

Conclusions:

• Spontaneous neural activity in the auditory cortex has a less correlated excitatory-inhibitory balance compared to evoked activity.
• This suggests distinct mechanisms govern spontaneous and evoked synaptic dynamics in the auditory cortex.