How can changes in synaptic strength contribute to short-term and long-term memory?

Neuroplasticity involves the brain's capacity to reorganize its connections by adjusting the strength or number of synapses between neurons. These synaptic modifications are fundamental to both short-term and long-term memory.12

Mechanisms of Synaptic Change

• Short-term effects: Changes in synaptic efficacy often drive short-term memory. For instance, habituation can occur when the closing of calcium channels reduces neurotransmitter release, weakening the response to repeated stimuli. Conversely, sensitization increases reflex strength through presynaptic facilitation, often mediated by an increase in second messenger molecules like cAMP.2
• Long-term effects: Long-term memory is associated with more enduring structural changes. Long-term potentiation (LTP) describes a long-lasting strengthening of postsynaptic responses following repeated stimulation. Over time, these processes can lead to physical alterations, such as changes in the number of active zones at nerve terminals, which stabilize the memory trace.32

These mechanisms demonstrate that the brain is not static; rather, it continuously adapts its neural networks to encode and retain new information through the dynamic regulation of synaptic strength.12