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.
Synapse = point of impulse transmission between neurons; impulses are transmitted from pre-synaptic neurons to post-synaptic neurons. Synapses usually occur between the axon of a pre-synaptic neuron & a dendrite or cell body of a post-synaptic neuron.