Synaptic plasticity refers to the ability of synapses to strengthen or weaken over time, serving as a primary cellular basis for learning and memory.

### Why this is right The material explicitly describes the ability of synapses to strengthen or weaken over time as the physical basis of learning. Persistent changes in connection strength can alter how neural circuits respond. ### The concept Synaptic plasticity covers changes at connections between neurons. Long-term potentiation (LTP) and long-term depression (LTD) are examples of opposite forms of such change. This account does not mean that learning is explained by synapses alone; the material also identifies brain regions and neurotransmitters involved in learning. ### Terms - **Synapse**: A junction through which neurons communicate. - **LTP**: Long-term potentiation, lasting synaptic strengthening. - **LTD**: Long-term depression, lasting synaptic weakening. ### Remember Plasticity describes a mechanism that helps make learning physically possible in neural circuits.