In horse racing, these definitions may differ: For example, in the British Isles, Thoroughbred horse racing defines colts and fillies as less than five years old. However, Australian Thoroughbred racing defines colts and fillies as less than four years old.
For the general concept of brain plasticity, see neuroplasticity. In neuroscience, synaptic plasticity is the ability of synapses to strengthen or weaken over time, in response to increases or decreases in their activity. Plastic change also results from the alteration of the number of neurotransmitter receptors located on a synapse.
Periventricular heterotopia (PH) has been interpreted as a disorder in neuronal migration where newly born neurons fail to migrate from their birthplace along the lining of the lateral ventricles of the brain, thereby giving rise to the characteristic ectopically placed neuronal nodules (figure 1â).