Periodic Reporting for period 2 - EXPERIENTIA (Assembly and plasticity of inhibitory cortical networks by early learning experience)
Reporting period: 2022-07-01 to 2023-12-31
The extraordinary diversity of animal behaviors relies on the precise assembly and fine-tuning of synapses in the brain. This connectivity reaches an exceptional level of complexity in the mammalian cerebral cortex, where experience-dependent plasticity endows neural circuits with the flexibility required for adapting to a continuously changing environment, the neural basis of learning. However, while learning occurs throughout our existence, several studies have shown that learning during early postnatal development transforms functional performance later in life. Why is learning a motor skill or language much easier early in life? And why if we become competent in a new skill during childhood, it would stay for our entire life? What does it change in a brain exposed to early sensory experience compared to adulthood that can explain a better performance? These are the questions we are addressing in this research proposal. Understanding how experience during development can shape neural circuits is not only a fundamental question in Neuroscience but can also give us insights on how to enhance learning during adulthood which will benefit our society, particularly on problems associated with the elderly population (e.g. decreased memory and cognitive function, dementia, etc).
The benefits of early sensory stimulation have been difficult to study in humans due to the complex environments in which we live and the variability across individuals. However, animal studies have shown enhanced environments during development increase performance in specific tasks. The enriched environment (EE) paradigm enhances the sensory experience. Enriched animals are raised in large groups and maintained in stimulating environments where various objects are present in the cage, which are optimal conditions for enhanced exploration. We are using this paradigm to address our main objectives: (1) To characterize the impact of early sensory experience on inhibitory cortical circuits; (2) To identify molecular mechanisms mediating the effect of early sensory experience.
The main achievements since the beginning of the project have been:
1.- We found synaptic changes associated with early and late enhanced experience.
2.- We found a remarkable difference in the pattern of neuronal activity when animals exposed to EE were compared with mice housed in standard cages.
3.- Our data are consistent with better performance of mice exposed to an early sensory experience on a task used to explore the discrimination of sensory stimuli (bowls with two different rugosity patterns).
Our findings suggest that exposure to an enriched experience causes changes in the circuits and networks that allow better task performance.
The main achievements since the beginning of the project have been:
1.- We found synaptic changes associated with early and late enhanced experience.
2.- We found a remarkable difference in the pattern of neuronal activity when animals exposed to EE were compared with mice housed in standard cages.
3.- Our data are consistent with better performance of mice exposed to an early sensory experience on a task used to explore the discrimination of sensory stimuli (bowls with two different rugosity patterns).
Our findings suggest that exposure to an enriched experience causes changes in the circuits and networks that allow better task performance.
We are starting to understand some of the main cellular principles on why early experiences modify our circuitries to improve our memories and learning, resulting in better performance. The expected result at the end of the project is that we get some insight into the genes driving the reported modifications in the circuitry and others that we may discover in the coming years.