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Differential modulation of thalamo-parietal interactions by varying depths of isoflurane anesthesia

View Article: PubMed Central - PubMed

ABSTRACT

The thalamus is thought to relay peripheral sensory information to the somatosensory cortex in the parietal lobe. Long-range thalamo-parietal interactions play an important role in inducing the effect of anesthetic. However, whether these interaction changes vary with different levels of anesthesia is not known. In the present study, we investigated the influence of different levels of isoflurane-induced anesthesia on the functional connectivity between the thalamus and the parietal region. Microelectrodes were implanted in rats to record local field potentials (LFPs). The rats underwent different levels of isoflurane anesthesia [deep anesthesia: isoflurane (ISO) 2.5 vol%, light anesthesia (ISO 1 vol%), awake, and recovery state] and LFPs were recorded from four different brain areas (left parietal, right parietal, left thalamus, and right thalamus). Partial directed coherence (PDC) was calculated for these areas. With increasing depth of anesthesia, the PDC in the thalamus-to-parietal direction was significantly increased mainly in the high frequency ranges; however, in the parietal-to-thalamus direction, the increase was mainly in the low frequency band. For both directions, the PDC changes were prominent in the alpha frequency band. Functional interactions between the thalamus and parietal area are augmented proportionally to the anesthesia level. This relationship may pave the way for better understanding of the neural processing of sensory inputs from the periphery under different levels of anesthesia.

No MeSH data available.


Block diagram for calculating the Partial Directed Coherence (PDC).
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pone.0175191.g002: Block diagram for calculating the Partial Directed Coherence (PDC).

Mentions: The results of PDC were divided in the following frequency bands: delta (1–4 Hz), theta (4–8 Hz), alpha (8–12 Hz), beta (12–30 Hz), and gamma (30–60 Hz) and was averaged for each respective frequency band. Therefore, the total number of PDC feature is 4000 (10 [subjects]×4 [stages]×20 [epoch]×5 [bands]). The overall PDC process structure is represented in Fig 2. The statistical differences in PDC for each frequency band at different anesthetic states were calculated by a Friedman test followed by Dunn’s post-hoc test using a free statistical software R (R 2.13.1) [13]. A P-value less than 0.05 was considered statistically significant.


Differential modulation of thalamo-parietal interactions by varying depths of isoflurane anesthesia
Block diagram for calculating the Partial Directed Coherence (PDC).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5383263&req=5

pone.0175191.g002: Block diagram for calculating the Partial Directed Coherence (PDC).
Mentions: The results of PDC were divided in the following frequency bands: delta (1–4 Hz), theta (4–8 Hz), alpha (8–12 Hz), beta (12–30 Hz), and gamma (30–60 Hz) and was averaged for each respective frequency band. Therefore, the total number of PDC feature is 4000 (10 [subjects]×4 [stages]×20 [epoch]×5 [bands]). The overall PDC process structure is represented in Fig 2. The statistical differences in PDC for each frequency band at different anesthetic states were calculated by a Friedman test followed by Dunn’s post-hoc test using a free statistical software R (R 2.13.1) [13]. A P-value less than 0.05 was considered statistically significant.

View Article: PubMed Central - PubMed

ABSTRACT

The thalamus is thought to relay peripheral sensory information to the somatosensory cortex in the parietal lobe. Long-range thalamo-parietal interactions play an important role in inducing the effect of anesthetic. However, whether these interaction changes vary with different levels of anesthesia is not known. In the present study, we investigated the influence of different levels of isoflurane-induced anesthesia on the functional connectivity between the thalamus and the parietal region. Microelectrodes were implanted in rats to record local field potentials (LFPs). The rats underwent different levels of isoflurane anesthesia [deep anesthesia: isoflurane (ISO) 2.5 vol%, light anesthesia (ISO 1 vol%), awake, and recovery state] and LFPs were recorded from four different brain areas (left parietal, right parietal, left thalamus, and right thalamus). Partial directed coherence (PDC) was calculated for these areas. With increasing depth of anesthesia, the PDC in the thalamus-to-parietal direction was significantly increased mainly in the high frequency ranges; however, in the parietal-to-thalamus direction, the increase was mainly in the low frequency band. For both directions, the PDC changes were prominent in the alpha frequency band. Functional interactions between the thalamus and parietal area are augmented proportionally to the anesthesia level. This relationship may pave the way for better understanding of the neural processing of sensory inputs from the periphery under different levels of anesthesia.

No MeSH data available.