Details

Autor(en) / Beteiligte

• Speigel, Iris A.
• Patel, Kishan
• Hemmings, Hugh C.

Titel

Distinct effects of volatile and intravenous anaesthetics on presynaptic calcium dynamics in mouse hippocampal GABAergic neurones

Ist Teil von

• British journal of anaesthesia : BJA, 2022-06, Vol.128 (6), p.1019-1028

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• General anaesthetics have marked effects on synaptic transmission, but their neuronal and circuit-level effects remain unclear. The volatile anaesthetic isoflurane differentially inhibits synaptic vesicle exocytosis in specific neuronal subtypes, but whether other common anaesthetics also have neurone-subtype-specific actions is unknown. We used the genetically encoded fluorescent Ca2+ sensor GCaMP6f to compare the pharmacological effects of isoflurane, sevoflurane, propofol, and ketamine on presynaptic excitability in hippocampal glutamatergic neurones and in hippocampal parvalbumin-, somatostatin-, and vasoactive intestinal peptide-expressing (PV+, SST+, and VIP+, respectively) GABAergic interneurones. Isoflurane and sevoflurane depressed activity-driven presynaptic Ca2+ transients in a neurone-type-specific manner, with greater potency for inhibition of glutamate and SST+ compared with PV+ and VIP+ neurone presynaptic activation. In contrast, clinical concentrations of propofol (1 μM) or ketamine (15 μM) had no significant effects on presynaptic activation. Propofol potentiated evoked Ca2+ entry in PV+ interneurones but only at a supraclinical concentration (3 μM). Anaesthetic-agent-selective effects on presynaptic Ca2+ entry have functional implications for hippocampal circuit function during i.v. or volatile anaesthetic-mediated anaesthesia. Hippocampal interneurones have distinct subtype-specific sensitivities to volatile anaesthetic actions on presynaptic Ca2+, which are similar between isoflurane and sevoflurane.