NMDA receptors are also associated with synaptic plasticity. Studies show that the NMDA receptor is involved in regulating synaptic plasticity and memory. The NMDA receptor is very important for controlling synaptic plasticity and memory function. HDACs are important regulators of synaptic formation, synaptic plasticity, and long-term memory formation. Additionally, endocannabinoids play an important role in regulating various forms of synaptic plasticity. NMDA induces a calcium flux that allows for synaptic plasticity which is crucial for AHN. Every kind of synaptic plasticity has different computational uses. This is known as Hebbian synaptic plasticity. Both GluR1 and GluR2 play an important role in synaptic plasticity. This is useful to study the molecular events during the induction of synaptic plasticity. It plays a key role in synaptic plasticity and so in learning. Adaptations include changes in morphology, physiology, phenology, and plasticity. LTP is also a model for studying the synaptic basis of Hebbian plasticity. This enables them to act as coincidence detectors for synaptic plasticity. Such an adaptation is an example of phenotypic plasticity.