Final answer:
CREB is a transcription factor involved in the formation of long-term memories and regulates gene expression for neural plasticity. Long-term potentiation and long-term depression are processes in synaptic transmission integral for memory strength and pruning, and both are critical for learning and memory adaptation.
Step-by-step explanation:
CREB (cAMP response element-binding protein) is a cellular transcription factor that plays a vital role in the formation of long-term memories, also known as engrams. CREB influences engram formation by regulating the expression of genes involved in neural plasticity and memory function. When an individual experiences a strong emotional event, the activation of CREB is thought to facilitate the conversion of short-term memories into long-term memories by enhancing synaptic strength and promoting changes in neural connectivity.
In the context of memory formation, long-term potentiation (LTP) and long-term depression (LTD) are critical processes that affect how information is transmitted across synapses. LTP is an increase in synaptic strength that follows repeated stimulation, and it is associated with the strengthening of memory. LTD, on the other hand, is a decrease in synaptic strength, which is involved in the weakening or pruning of memory connections that are less used or no longer relevant. Both LTP and LTD are essential for learning, memory adjustment, and the overall plasticity of the brain.