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Updated: Jun 27, 2026
Two-photon Imaging of Microglial Processes' Attraction Toward ATP or Serotonin in Acute Brain Slices
Published on: January 31, 2019
ATP and NO dually control migration of microglia to nerve lesions
Yuanli Duan1, Christie L Sahley, Kenneth J Muller
1Department of Physiology and Biophysics (R-430), University of Miami School of Medicine, Miami, Florida 33136, USA.
Abstract:
Microglia migrate rapidly to lesions in the central nervous system (CNS), presumably in response to chemoattractants including ATP released directly or indirectly by the injury. Previous work on the leech has shown that nitric oxide (NO), generated at the lesion, is both a stop signal for microglia at the lesion and crucial for their directed migration from hundreds of micrometers away within the nerve cord, perhaps mediated by a soluble guanylate cyclase (sGC). In this study, application of 100 microM ATP caused maximal movement of microglia in leech nerve cords. The nucleotides ADP, UTP, and the nonhydrolyzable ATP analog AMP-PNP (adenyl-5'-yl imidodiphosphate) also caused movement, whereas AMP, cAMP, and adenosine were without effect. Both movement in ATP and migration after injury were slowed by 50 microM reactive blue 2 (RB2), an antagonist of purinergic receptors, without influencing the direction of movement. This contrasted with the effect of the NO scavenger cPTIO (2-(4-carboxyphenyl)-4,4,5,5-teramethylimidazoline-oxyl-3-oxide), which misdirected movement when applied at 1 mM. The cPTIO reduced cGMP immunoreactivity without changing the immunoreactivity of eNOS (endothelial nitric oxide synthase), which accompanies increased NOS activity after nerve cord injury, consistent with involvement of sGC. Moreover, the sGC-specific inhibitor LY83583 applied at 50 microM had a similar effect, in agreement with previous results with methylene blue. Taken together, the experiments support the hypothesis that ATP released directly or indirectly by injury activates microglia to move, whereas NO that activates sGC directs migration of microglia to CNS lesions.
Insights
Adenosine triphosphate (ATP) signals microglia to move towards injury sites in the central nervous system (CNS). Nitric oxide (NO) then directs their precise migration, involving soluble guanylate cyclase (sGC).
Area of Science:
- Neuroscience
- Cell Biology
- Biochemistry
Background:
- Microglia rapidly migrate to central nervous system (CNS) lesions, guided by chemoattractants like ATP.
- Nitric oxide (NO) acts as a stop signal and directs microglial migration in the CNS, potentially via soluble guanylate cyclase (sGC).
Purpose of the Study:
- To investigate the roles of ATP and NO in microglial migration towards CNS lesions.
- To elucidate the signaling pathways involved in ATP-induced microglial movement and NO-mediated directional guidance.
Main Methods:
- Utilized leech nerve cord preparations to study microglial responses.
- Applied various nucleotides (ATP, ADP, UTP, AMP-PNP) and inhibitors (RB2, cPTIO, LY83583) to assess microglial migration.
- Examined cGMP and eNOS immunoreactivity to understand NO signaling pathways.
Main Results:
- ATP, ADP, UTP, and AMP-PNP induced maximal microglial movement; AMP, cAMP, and adenosine had no effect.
- Reactive blue 2 (RB2) slowed ATP-induced movement and injury-related migration but did not alter direction.
- The NO scavenger cPTIO and the sGC inhibitor LY83583 disrupted directed migration and reduced cGMP levels, implicating sGC in NO-mediated guidance.
Conclusions:
- ATP released during injury acts as a chemoattractant, initiating microglial movement.
- Nitric oxide (NO), acting through soluble guanylate cyclase (sGC), is crucial for directing microglia to CNS lesions.
