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An Enriched Environment Leads to Increased Synaptic Plasticity-Associated miRNA Levels after Experimental
Fulya Buge Ergen1, Didem Turgut Cosan2, Turan Kandemir3
1Department of Interdisciplinary Neuroscience, Health Science Institute, Eskisehir Osmangazi University, Eskisehir, Turkey.
Background And Purpose:
In subarachnoid hemorrhage (SAH), impairments in motor and cognitive functions may occur and continue in later periods. MicroRNAs (miRNAs) are small non-coding RNAs that can directly or indirectly affect synaptic reconstruction. mir-132, mir-134, and mir-138 are the leading miRNAs that can be effective on some neurological functions through its effects on synaptic plasticity in the relevant brain areas. In our study, it was aimed to determine the levels of miRNAs in the hippocampus and frontal lobe of rats exposed to different environmental conditions after the experimental SAH.
Methods:
SAH was created using the cisterna magna double blood-injection method. Brain tissues were collected at different times after the last blood injection. Rats were grouped according to the different environmental conditions in which they were kept. Expression levels of miRNAs were performed by qPCR and ultrastructural changes in samples were determined by transmission electron microscopy (TEM).
Results:
After SAH, miR-132, miR-134, and miR-138 expressions in the frontal lobes of rats increased in impoverished environment on the 7th day and in the enriched environment on the 14th day. It was observed that the myelin and microtubule structures in the axons that were disrupted after SAH were more organized and stable in the enriched environment.
Conclusions:
After SAH, different environmental conditions may affect the miRNA levels associated with synaptic plasticity and microtubule organization in the frontal lobe, and this might have some effects especially on cognitive and motor functions related to this brain area.
Insights
Environmental conditions after subarachnoid hemorrhage (SAH) impact microRNA (miRNA) levels in rat brains. Enriched environments promoted myelin and microtubule organization, potentially improving motor and cognitive functions.
Area of Science:
- Neuroscience
- Molecular Biology
- Environmental Psychology
Background:
- Subarachnoid hemorrhage (SAH) can lead to persistent motor and cognitive deficits.
- MicroRNAs (miRNAs) are key regulators of synaptic plasticity and neuronal function.
- Specific miRNAs, including miR-132, miR-134, and miR-138, are implicated in neurological functions.
Purpose of the Study:
- To investigate the impact of different environmental conditions on miRNA expression in the hippocampus and frontal lobe following experimental SAH in rats.
- To assess the relationship between environmental enrichment and synaptic plasticity markers after SAH.
Main Methods:
- SAH was induced in rats using a double blood-injection method.
- Rats were housed in different environmental conditions (impoverished vs. enriched).
- miRNA expression was quantified using quantitative polymerase chain reaction (qPCR).
- Ultrastructural changes in brain tissues were examined via transmission electron microscopy (TEM).
Main Results:
- Following SAH, miR-132, miR-134, and miR-138 expression levels increased in the frontal lobes of rats in an impoverished environment (day 7) and an enriched environment (day 14).
- Enriched environments facilitated the organization and stability of myelin and microtubule structures in axons damaged by SAH.
- These findings suggest a differential response of miRNA expression to environmental stimuli post-SAH.
Conclusions:
- Environmental conditions significantly influence miRNA levels associated with synaptic plasticity in the frontal lobe after SAH.
- The observed changes in miRNA expression and ultrastructure in enriched environments may contribute to improved cognitive and motor functions.
- This study highlights the potential of environmental interventions in mitigating the neurological consequences of SAH.
