# Analysis of mitochondrial Complex I activity and ATP hydrolysis capacity of ATP synthase in developing rat brains using frozen tissues

## TL;DR

This study improves methods to measure mitochondrial functions in frozen rat brain tissue and finds that key mitochondrial activities increase with brain development.

## Contribution

The study introduces optimized protocols for measuring Complex I activity and ATP synthase reverse action in frozen tissues.

## Key findings

- Specific functions of mitochondrial Complex I increase linearly with brain development.
- ATP synthase's ATP hydrolysis capacity also increases linearly during brain development.

## Abstract

In a previous study, we analyzed the activity of the mitochondrial respiratory Complex II, Complex IV and ATP synthase in frozen tissues of postnatal rat brains (Yao et al., 2023). In this study, we expand our capability of assessing mitochondrial functions using frozen tissue samples. We optimize protocols for measuring the activity of Complex I, and ATP hydrolysis capacity – known as the reverse action – of ATP synthase. We show that the specific functions of these mitochondrial proteins increase linearly as the brain develops.