Modification of Neural Circuits with Experience

Experience gained…

• In utero• Development• Adulthood

– By experience, we mean changes in the chemical and external environments

– Really hot research area (epigenetics)

Changes to Neuron Diversity in Utero

• Cellular Interaction Model– Neuron diversity reliant on the extent and type

of intracellular signaling– These signaling cascades are sensitive to

changes in pH, calcium levels, and other molecular factors that could be modified by environmental stressors

– This, in turn, can influence where these neurons migrate to in the cortex , for example

Imprinting After Birth

Even in humans

During adolescence

The Importance of Time During Development

The Importance of Length During the Critical Period

Whole System Changes During the Critical Period

Complementary Changes in Neuronal Architecture

Hebbian Theory• Neurons that wire together, fire together

Somatosensory Cortex of An Amputee

Genetic Changes Due to Environmental Stressors (Epigenetics)

• affects DNA transcription and translation which can have a HUGE impact on neuron function

• How? adding of DNA methyl groups, preventing or enabling unwinding of DNA around chromatin, to name a few

• Hugely popular in psychiatric research

Optional Reading

• From my blog “Dormivigilia”– www.dormivigilia.com

• Basic review of epigenetic factors and the effects of early-life stress on subsequent development and social relationships