Correlation between Cortical State and Locus Coeruleus Activity: Implications for Sensory Coding in Rat Barrel Cortex
| Autor: | Zeinab eFazlali, Yadollah eRanjbar-Slamloo, Mehdi eAdibi, Ehsan eArabzadeh |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Male somatosensory cortex Cognitive Neuroscience Statistics as Topic Neuroscience (miscellaneous) Normal Distribution Action Potentials Prefrontal Cortex Stimulation Stimulus (physiology) Somatosensory system lcsh:RC321-571 03 medical and health sciences Cellular and Molecular Neuroscience 0302 clinical medicine Physical Stimulation Neural Pathways Reaction Time Animals Cortical Synchronization Rats Wistar Prefrontal cortex lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry Original Research vibrissal system Neurons Sensory stimulation therapy Chemistry locus coeruleus desynchronized Electroencephalography Barrel cortex Sensory Systems Rats 030104 developmental biology ROC Curve Vibrissae synchronized neuromodulation Locus coeruleus Neuroscience 030217 neurology & neurosurgery cortical state |
| Zdroj: | Frontiers in Neural Circuits Frontiers in Neural Circuits, Vol 10 (2016) |
| ISSN: | 1662-5110 |
| Popis: | Cortical state modulates the background activity of cortical neurons, and their evoked response to sensory stimulation. Multiple mechanisms are involved in switching between cortical states including various neuromodulatory systems. Locus Coeruleus (LC) is one of the major neuromodulatory nuclei in the brainstem with widespread projections throughout the brain and modulates the activity of cells and networks. Here, we quantified the link between the LC spontaneous activity, cortical state and sensory processing in the rat vibrissal somatosensory “barrel” cortex (BC). We simultaneously recorded unit activity from LC and BC along with prefrontal electroencephalogram (EEG) while presenting brief whisker deflections under urethane anesthesia. The ratio of low to high frequency components of EEG (referred to as the L/H ratio) was employed to identify cortical state. We found that the spontaneous activity of LC units exhibited a negative correlation with the L/H ratio. Cross-correlation analysis revealed that changes in LC firing preceded changes in the cortical state: the correlation of the LC firing profile with the L/H ratio was maximal at an average lag of −1.2 s. We further quantified BC neuronal responses to whisker stimulation during the synchronized and desynchronized states. In the desynchronized state, BC neurons showed lower stimulus detection threshold, higher response fidelity, and shorter response latency. The most prominent change was observed in the late phase of BC evoked activity (100–400 ms post stimulus onset): almost every BC unit exhibited a greater late response during the desynchronized state. Categorization of the BC evoked responses based on LC activity (into high and low LC discharge rates) resulted in highly similar response profiles compared to categorization based on the cortical state (low and high L/H ratios). These findings provide evidence for the involvement of the LC neuromodulatory system in desynchronization of cortical state and the consequent enhancement of sensory coding efficiency. |
| Databáze: | OpenAIRE |
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