2. Academic Validation
  3. GABAergic neurons of anterior thalamic reticular nucleus regulate states of consciousness in propofol- and isoflurane-mediated general anesthesia

GABAergic neurons of anterior thalamic reticular nucleus regulate states of consciousness in propofol- and isoflurane-mediated general anesthesia

  • CNS Neurosci Ther. 2024 Jun;30(6):e14782. doi: 10.1111/cns.14782.
Rulan Yi 1 2 3 4,  Shiyu Cheng 2 3 4,  Fuwang Zhong 2 3 4,  Dan Luo 2 3 4,  Ying You 2 3 4,  Tian Yu 1 2 3 4,  Haiying Wang 1 2 3 4,  Liang Zhou 1 2 3 4,  Yu Zhang 1 2 3 4
Affiliations

Affiliations

  • 1 Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.
  • 2 Key Laboratory of Anesthesia and Organ Protection (Zunyi Medical University), Ministry of Education, Zunyi Medical University, Zunyi, China.
  • 3 Key Laboratory of Brain Science, Zunyi Medical University, Zunyi, China.
  • 4 Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Zunyi, China.
PMID: 38828651 DOI: 10.1111/cns.14782
Abstract

Background: The thalamus system plays critical roles in the regulation of reversible unconsciousness induced by general anesthetics, especially the arousal stage of general anesthesia (GA). But the function of thalamus in GA-induced loss of consciousness (LOC) is little known. The thalamic reticular nucleus (TRN) is the only GABAergic neurons-composed nucleus in the thalamus, which is composed of parvalbumin (PV) and somatostatin (SST)-expressing GABAergic neurons. The anterior sector of TRN (aTRN) is indicated to participate in the induction of anesthesia, but the roles remain unclear. This study aimed to reveal the role of the aTRN in propofol and isoflurane anesthesia.

Methods: We first set up c-Fos straining to monitor the activity variation of aTRNPV and aTRNSST neurons during propofol and isoflurane anesthesia. Subsequently, optogenetic tools were utilized to activate aTRNPV and aTRNSST neurons to elucidate the roles of aTRNPV and aTRNSST neurons in propofol and isoflurane anesthesia. Electroencephalogram (EEG) recordings and behavioral tests were recorded and analyzed. Lastly, chemogenetic activation of the aTRNPV neurons was applied to confirm the function of the aTRN neurons in propofol and isoflurane anesthesia.

Results: c-Fos straining showed that both aTRNPV and aTRNSST neurons are activated during the LOC period of propofol and isoflurane anesthesia. Optogenetic activation of aTRNPV and aTRNSST neurons promoted isoflurane induction and delayed the recovery of consciousness (ROC) after propofol and isoflurane anesthesia, meanwhile chemogenetic activation of the aTRNPV neurons displayed the similar effects. Moreover, optogenetic and chemogenetic activation of the aTRN neurons resulted in the accumulated burst suppression ratio (BSR) during propofol and isoflurane GA, although they represented different effects on the power distribution of EEG frequency.

Conclusion: Our findings reveal that the aTRN GABAergic neurons play a critical role in promoting the induction of propofol- and isoflurane-mediated GA.

Keywords

anterior thalamic reticular nucleus; general anesthesia; loss of consciousness (LOC); parvalbumin; somatostatin.

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