Metaplasticity refers to the regulation of synaptic plasticity, ensuring it occurs at the right time and extent. It involves intercellular signaling molecules that alter synaptic plasticity potential. Long-term potentiation (LTP) and long-term depression (LTD) are key forms of synaptic plasticity, with LTP increasing synaptic strength and LTD decreasing it. Excitotoxicity, caused by excessive glutamate receptor activation, leads to cell death. Tetanus, a high-frequency stimulation, induces activity-dependent plasticity. Neurons can modify their structure and function through activity, crucial for learning and responding to brain damage. Synaptic plasticity, like LTP and LTD, is regulated by various signaling molecules, including catecholamines, GABA, acetylcholine, cytokines, and hormones. Metaplasticity, a form of plasticity regulation that persists over time, changes the ability of synapses to exhibit plasticity. It differs from conventional plasticity modulation as it involves changes that persist after the initial activity. NMDA receptor activation can induce metaplastic changes that inhibit LTP. This effect is mediated by NMDARs, adenosine A2 receptors, p38 MAPK, and protein phosphatases. Metaplasticity involves mechanisms such as NMDAR-mediated changes that affect LTD and LTP thresholds. The Bienenstock, Cooper, and Munro (BCM) model predicts that cell-wide modifications in LTP induction thresholds are driven by postsynaptic firing history. Metaplasticity can be influenced by metabotropic glutamate receptors (mGluRs), which can enhance LTP induction and persistence. mGluR activation can also facilitate NMDAR function or trafficking. Heterosynaptic metaplasticity, where activity at one synapse affects plasticity at neighboring synapses, has been observed. This is predicted by the BCM model and involves changes in plasticity thresholds. Environmental stimuli, such as enriched environments or stress, can induce metaplasticity, affecting synaptic plasticity. Stress can inhibit LTP through glucocorticoid receptors in the dorsal hippocampus and facilitate LTP through mineralocorticoid receptors in the ventral hippocampus. Developmental metaplasticity in the visual cortex is influenced by light exposure, altering NMDAR subunit composition. Learning-associated metaplasticity involves changes in cell excitability and plasticity thresholds, affecting learning processes. Eye-blink conditioning and spatial training can induce changes in slow afterhyperpolarization (AHP), enhancing learning. Metaplasticity is also linked to transcriptional processes, with histone acetylation and DNA methylation playing roles in memory consolidation. Clinical relevance includes conditions like amblyopia and ischaemic preconditioning, where metaplastic mechanisms may play a role in protecting tissues. Overall, metaplasticity is crucial for normal cognition, learning, and memory, with ongoing research exploring its mechanisms andMetaplasticity refers to the regulation of synaptic plasticity, ensuring it occurs at the right time and extent. It involves intercellular signaling molecules that alter synaptic plasticity potential. Long-term potentiation (LTP) and long-term depression (LTD) are key forms of synaptic plasticity, with LTP increasing synaptic strength and LTD decreasing it. Excitotoxicity, caused by excessive glutamate receptor activation, leads to cell death. Tetanus, a high-frequency stimulation, induces activity-dependent plasticity. Neurons can modify their structure and function through activity, crucial for learning and responding to brain damage. Synaptic plasticity, like LTP and LTD, is regulated by various signaling molecules, including catecholamines, GABA, acetylcholine, cytokines, and hormones. Metaplasticity, a form of plasticity regulation that persists over time, changes the ability of synapses to exhibit plasticity. It differs from conventional plasticity modulation as it involves changes that persist after the initial activity. NMDA receptor activation can induce metaplastic changes that inhibit LTP. This effect is mediated by NMDARs, adenosine A2 receptors, p38 MAPK, and protein phosphatases. Metaplasticity involves mechanisms such as NMDAR-mediated changes that affect LTD and LTP thresholds. The Bienenstock, Cooper, and Munro (BCM) model predicts that cell-wide modifications in LTP induction thresholds are driven by postsynaptic firing history. Metaplasticity can be influenced by metabotropic glutamate receptors (mGluRs), which can enhance LTP induction and persistence. mGluR activation can also facilitate NMDAR function or trafficking. Heterosynaptic metaplasticity, where activity at one synapse affects plasticity at neighboring synapses, has been observed. This is predicted by the BCM model and involves changes in plasticity thresholds. Environmental stimuli, such as enriched environments or stress, can induce metaplasticity, affecting synaptic plasticity. Stress can inhibit LTP through glucocorticoid receptors in the dorsal hippocampus and facilitate LTP through mineralocorticoid receptors in the ventral hippocampus. Developmental metaplasticity in the visual cortex is influenced by light exposure, altering NMDAR subunit composition. Learning-associated metaplasticity involves changes in cell excitability and plasticity thresholds, affecting learning processes. Eye-blink conditioning and spatial training can induce changes in slow afterhyperpolarization (AHP), enhancing learning. Metaplasticity is also linked to transcriptional processes, with histone acetylation and DNA methylation playing roles in memory consolidation. Clinical relevance includes conditions like amblyopia and ischaemic preconditioning, where metaplastic mechanisms may play a role in protecting tissues. Overall, metaplasticity is crucial for normal cognition, learning, and memory, with ongoing research exploring its mechanisms and