Related Experiment Video
Updated: Jun 26, 2026
Isolation and Flow Cytometric Assessment of Neuroimmune Interactions in a Mini-Stroke Murine Model
Published on: June 20, 2025
Reduced neurogenesis after suppressed inflammation by minocycline in transient cerebral ischemia in rat
Beom Joon Kim1, Min-Jeong Kim, Jong-Moo Park
1Department of Neurology, Seoul National University Hospital, Jongno-Gu, Seoul, Republic of Korea.
Abstract:
Recently, the beneficial role of minocycline on endogenous neurogenesis after cerebral ischemia has been contradicted by many reports. We examined whether minocycline influences post-ischemic neurogenesis in the subventricular zone. Adult male Sprague-Dawley rats were subjected to focal cerebral ischemia for 2 h, and divided into a minocycline-treated (90 mg/Kg on reperfusion and 45 mg/Kg daily for maintenance) and a saline-treated group. Bromodeoxyuridine was injected to determine levels of cell proliferation. Inflammation was assessed by counting polymorphonuclear cell and activated microglia and by measuring myeloperoxidase activity. Endogenous neurogenesis was quantified by immunohistochemical staining and functional outcome was measured by infarct size and behavioral tests. Minocycline treatment decreased inflammation on 1st and 4th days after ischemia. BrdU-positive cells on 7th day (saline vs. minocycline: 602.80+/-146.96 vs. 399.40+/-109.69) and the number of double labeling cells of BrdU/NeuN on 7th day (13.00+/-4.36 vs. 6.40+/-2.07) and BrdU/DCx on 4th day (17.00+/-5.00 vs. 7.50+/-1.91) were significantly decreased in minocycline-treated rats. Infarct size and behavioral tests were not different. Our results indicate that minocycline may reduce immediate post-ischemic neurogenesis despite adequately suppressed inflammation.
Insights
Minocycline reduced inflammation and cell proliferation after stroke but also decreased neurogenesis. This suggests minocycline may hinder recovery by inhibiting new neuron formation despite its anti-inflammatory effects.
Area of Science:
- Neuroscience
- Pharmacology
- Regenerative Medicine
Background:
- Minocycline's role in neurogenesis post-cerebral ischemia is debated.
- Understanding minocycline's impact on endogenous neurogenesis is crucial for stroke recovery.
Purpose of the Study:
- To investigate the effect of minocycline on post-ischemic neurogenesis in the subventricular zone.
- To determine if minocycline influences cell proliferation and new neuron formation after focal cerebral ischemia.
Main Methods:
- Adult male rats underwent focal cerebral ischemia and received minocycline or saline treatment.
- Cell proliferation was assessed using Bromodeoxyuridine (BrdU) labeling.
- Inflammation, neurogenesis (BrdU/NeuN, BrdU/DCx), infarct size, and behavioral tests were evaluated.
Main Results:
- Minocycline significantly decreased inflammation markers on days 1 and 4 post-ischemia.
- BrdU-positive cells and neurogenesis markers (BrdU/NeuN, BrdU/DCx) were significantly reduced in minocycline-treated rats.
- No significant differences were observed in infarct size or behavioral outcomes between groups.
Conclusions:
- Minocycline suppresses inflammation following cerebral ischemia.
- Despite reduced inflammation, minocycline treatment inhibits immediate post-ischemic neurogenesis.
- The findings suggest minocycline may negatively impact recovery by reducing endogenous neurogenesis.
