Related Experiment Video
Updated: Jul 16, 2026
Intracerebroventricular Injection of Amyloid-β Peptides in Normal Mice to Acutely Induce Alzheimer-like Cognitive Deficits
Published on: March 16, 2016
Minocycline reduces microglial activation and improves behavioral deficits in a transgenic model of cerebral
Rong Fan1, Feng Xu, Mary Lou Previti
1Department of Medicine, Stony Brook University, Stony Brook, New York 11794, USA.
Abstract:
Cerebral microvascular amyloid beta protein (Abeta) deposition and associated neuroinflammation is increasingly recognized as an important component leading to cognitive impairment in Alzheimer's disease and related cerebral amyloid angiopathy disorders. Transgenic mice expressing the vasculotropic Dutch/Iowa (E693Q/D694N) mutant human Abeta precursor protein in brain (Tg-SwDI) accumulate abundant cerebral microvascular fibrillar amyloid deposits and exhibit robust neuroinflammation. In the present study, we investigated the effect of the anti-inflammatory drug minocycline on Abeta accumulation, neuroinflammation, and behavioral deficits in Tg-SwDI mice. Twelve-month-old mice were treated with saline or minocycline by intraperitoneal injection every other day for a total of 4 weeks. During the final week of treatment, the mice were tested for impaired learning and memory. Brains were then harvested for biochemical and immunohistochemical analysis. Minocycline treatment did not alter the cerebral deposition of Abeta or the restriction of fibrillar amyloid to the cerebral microvasculature. Similarly, minocycline-treated Tg-SwDI mice exhibited no change in the levels of total Abeta, the ratios of Abeta40 and Abeta42, or the amounts of soluble, insoluble, or oligomeric Abeta compared with the saline-treated control Tg-SwDI mice. In contrast, the numbers of activated microglia and levels of interleukin-6 were significantly reduced in minocycline-treated Tg-SwDI mice compared with saline-treated Tg-SwDI mice. In addition, there was a significant improvement in behavioral performance of the minocycline-treated Tg-SwDI mice. These finding suggest that anti-inflammatory treatment targeted for cerebral microvascular amyloid-induced microglial activation can improve cognitive deficits without altering the accumulation and distribution of Abeta.
Insights
Minocycline reduced neuroinflammation and improved cognitive deficits in mice with cerebral amyloid angiopathy. The drug did not affect amyloid beta deposition but lessened microglial activation and interleukin-6 levels.
Area of Science:
- Neuroscience
- Pharmacology
- Pathology
Background:
- Cerebral microvascular amyloid beta (Abeta) deposition and neuroinflammation contribute to cognitive decline in Alzheimer's disease and cerebral amyloid angiopathy (CAA).
- Transgenic SwDI mice exhibit Abeta accumulation in cerebral microvasculature and significant neuroinflammation.
Purpose of the Study:
- To investigate the effects of minocycline, an anti-inflammatory drug, on Abeta accumulation, neuroinflammation, and cognitive function in Tg-SwDI mice.
Main Methods:
- Twelve-month-old Tg-SwDI mice received minocycline or saline via intraperitoneal injection for 4 weeks.
- Behavioral tests assessed learning and memory during the final week of treatment.
- Brains were analyzed for Abeta deposition, neuroinflammation markers (activated microglia, IL-6), and Abeta species.
Main Results:
- Minocycline treatment did not alter cerebral Abeta deposition or its distribution in microvasculature.
- Levels of total Abeta, Abeta40/42 ratios, and soluble/insoluble/oligomeric Abeta remained unchanged.
- Activated microglia and interleukin-6 levels were significantly reduced in minocycline-treated mice.
- Minocycline treatment significantly improved behavioral performance in Tg-SwDI mice.
Conclusions:
- Anti-inflammatory treatment with minocycline can ameliorate cognitive deficits associated with cerebral microvascular amyloid.
- Minocycline effectively targets microglial activation and neuroinflammation without altering Abeta accumulation in this model.
- These findings suggest a therapeutic strategy for cognitive impairment in CAA disorders.
