Bilateral electrodermal activity during sleep and waking in the cat

Area of Science:

• Neuroscience
• Physiology
• Sleep Research

Background:

• Electrodermal activity (EDA), measured as skin potential responses (SPRs), is a psychophysiological indicator of sympathetic nervous system activity.
• Understanding EDA variations across vigilance states is crucial for interpreting autonomic responses.
• Bilateral differences in EDA may reflect underlying neural asymmetries.

Purpose of the Study:

• To investigate the characteristics of spontaneous and evoked SPRs in cats during different vigilance states (waking and sleep).
• To analyze the parallelism and bilateral differences of SPRs.
• To examine the influence of central nervous system stimulation on SPRs and their laterality.

Main Methods:

• Recording of electrodermal activity (EDA) as skin potential responses (SPRs) on the hindpaws of cats.
• Observation of SPRs during natural waking and sleep stages.
• Electrical stimulation of the reticular central tegmental field to evoke SPRs.
• Analysis of SPR amplitude, frequency, and bilateral differences.

Main Results:

• SPRs showed parallelism between paws but decreased significantly in amplitude and frequency from wakefulness to sleep.
• Most spontaneous SPRs were synchronous, with consistent bilateral differences (>0.1 mV) independent of sleep stage.
• Evoked SPRs exhibited lower bilateral asymmetry compared to spontaneous SPRs, with no significant variation across vigilance states.

Conclusions:

• Autonomic responses, as reflected by EDA, exhibit state-dependent changes during sleep.
• Consistent, albeit small, bilateral asymmetries in EDA exist and are influenced by both spontaneous activity and central nervous system modulation.
• These findings in cats provide insights into human EDA laterality and the interplay of central and peripheral factors.