Effects of propofol on presynaptic synapsin phosphorylation in the mouse brain in vivo.

The commonly used general anesthetic propofol can enhance the γ-aminobutyric acid-mediated inhibitory synaptic transmission and depress the glutamatergic excitatory synaptic transmission to achieve general anesthesia and other outcomes. In addition to the actions at postsynaptic sites, the modulation of presynaptic activity by propofol is thought to contribute to neurophysiological effects of the anesthetic, although potential targets of propofol within presynaptic nerve terminals are incompletely studied at present. In this study, we explored the possible linkage of propofol to synapsins, a family of neuron-specific phosphoproteins which are the most abundant proteins on presynaptic vesicles, in the adult mouse brain in vivo. We found that an intraperitoneal injection of propofol at a dose that caused loss of righting reflex increased basal levels of synapsin phosphorylation at the major representative phosphorylation sites (serine 9, serine 62/67, and serine 603) in the prefrontal cortex (PFC) of male and female mice. Propofol also elevated synapsin phosphorylation at these sites in the striatum and S9 and S62/67 phosphorylation in the hippocampus, while propofol had no effect on tyrosine hydroxylase phosphorylation in striatal nerve terminals. Total synapsin protein expression in the PFC, hippocampus, and striatum was not altered by propofol. These results reveal that synapsin could be a novel substrate of propofol in the presynaptic neurotransmitter release machinery. Propofol possesses the ability to upregulate synapsin phosphorylation in broad mouse brain regions.

Long-Term Complications of COVID-19 Infection in Adolescents and Children.

Purpose of Review: Compared to adults, post-COVID-19 symptoms are uncommon and have not been thoroughly evaluated in children. This review summarizes the literature in terms of persistent symptoms in children and adolescents after SARS-CoV-2 infection. Recent Findings: Children were less likely to develop long COVID when compared to adults. Older children (e.g., adolescents) and those who had symptomatic COVID-19 had a higher probability for long COVID. Summary: Families and health care providers need to be aware of a new constellation of long COVID symptoms in the pediatric population. More evidence and time are needed to better understand the potential effects of long COVID-19 in children and adolescents. In comparison to adults, children are less likely to have persistent COVID-19 symptoms.