As the brain's resident immune cells, microglia perform crucial functions such as phagocytosis, neuronal network maintenance, and injury restoration by adopting various phenotypes. Dynamic imaging of these phenotypes is essential for accessing brain diseases and therapeutic responses. Although numerous probes are available for imaging pro-inflammatory microglia, no PET tracers have been developed specifically to visualize anti-inflammatory microglia. In this study, we present an ¹⁸F-labeled PET tracer (QTFT) that targets the P2Y₁₂, a receptor highly expressed on anti-inflammatory microglia. [¹⁸F]QTFT exhibited high binding affinity to the P2Y₁₂ (14.43 nmol/L) and superior blood-brain barrier permeability compared to other candidates. Micro-PET imaging in IL-4-induced neuroinflammation models showed higher [¹⁸F]QTFT uptake in lesions compared to the contralateral normal brain tissues. Importantly, this specific uptake could be blocked by QTFT or a P2Y₁₂ antagonist. Furthermore, [¹⁸F]QTFT visualized brain lesions in mouse models of epilepsy, glioma, and aging by targeting the aberrantly expressed P2Y₁₂ in anti-inflammatory microglia. In a pilot clinical study, [¹⁸F]QTFT successfully located epileptic foci, showing enhanced radioactive signals in a patient with epilepsy. Collectively, these studies suggest that [¹⁸F]QTFT could serve as a valuable diagnostic tool for imaging various brain disorders by targeting P2Y₁₂ overexpressed in anti-inflammatory microglia.

AIM:To test and compare the perceptual eye position and fixation stability of adolescents with emmetropia and adolescents with low myopia, investigating the characteristics of the perceptual eye position and fixation stability of adolescents with low myopia.METHODS: Cross-sectional study. A total of 132 adolescents(264 eyes)who visited in the ophthalmology clinic of our hospital from April to December 2023 were randomly selected as the research subjects. Participants were categorized into normal control group(n=45, 90 eyes), simple low myopia group(n=45, 90 eyes)and low myopia with anisometropia group(n=42, 84 eyes)according to their refractive status and were underwent assessments for perceptual eye position and fixation stability.RESULTS: Compared with the normal control group, the static and dynamic horizontal perceptual eye position deviation of the simple low myopia group and the low myopia with anisometropia group were significantly increased(P<0.05). Compared with the simple low myopia group, the static and dynamic horizontal perceptual eye position deviation of the low myopia with anisometropia group were significantly increased(P<0.05). There was no significant difference in static and dynamic vertical perceptual eye position deviation among the three groups(P>0.05); compared with the normal control group, the horizontal and vertical fixation stability of the simple low myopia group and the low myopia with anisometropia group were significantly worse(all P<0.01), but there was no differences in the simple low myopia group and the low myopia with anisometropia group(P >0.05).CONCLUSION: Abnormalities are observed in perceptual eye position and fixation stability function in adolescents with low myopia compared with those adolescents with emmetropia, even at best corrected visual acuity. The occurrence of anisometropia could lead to an increased degree of horizontal perceptual eye position displacement.