Short Communication - Neurophysiology Research (2023) Volume 5, Issue 3
Synaptic remodeling through Long-Term Depression (LTD) and implications for plasticity and learningAllin Wang*
Department of Psychology, City University of New York, New York, USA
- *Corresponding Author:
- Allin Wang
Department of Psychology
City University of New York
New York, USA
Received: 29-May-2023, Manuscript No. AANR-23-103725; Editor assigned: 01-Jun-2023, PreQC No. AANR-23-103725(PQ); Reviewed: 16-Jun-2023, QC No. AANR-23-103725; Revised: 19-Jun-2023, Manuscript No. AANR-23-103725(R); Published: 23-Jun-2023, DOI: 10.35841/aanr-5.3.152
Citation: Wang A. Synaptic remodeling through Long-Term Depression (LTD) and implications for plasticity and learning. Neurophysiol Res. 2023; 5(3):152
Long-Term Depression (LTD) is a form of synaptic plasticity that involves the long-lasting decrease in synaptic strength between neurons. It is considered the counterpart of Long- Term Potentiation (LTP), which is an increase in synaptic strength. Both LTD and LTP play crucial roles in learning, memory formation and overall brain function. Modulation of long-term depression can occur through various mechanisms and is influenced by a range of factors. Here are a few important factors and mechanisms involved in the modulation of LTD .
Calcium signaling: Calcium ions play a crucial role in the induction and modulation of LTD. The entry of calcium into postsynaptic neurons is necessary for the activation of signaling pathways that lead to the expression of LTD. Modulation of calcium levels can alter the magnitude and duration of LTD.
Glutamate receptors: LTD is often mediated by the activation of glutamate receptors, particularly the metabotropic Glutamate Receptors (mGluRs). These receptors initiate intracellular signaling cascades that ultimately lead to the decrease in synaptic strength. Modulation of glutamate receptor function can impact the induction and expression of LTD .
Noradrenaline (Norepinephrine): Noradrenaline is a neuromodulator that regulates attention, arousal and stress response. It can influence synaptic plasticity, including LTD, in different brain regions. Activation of adrenergic receptors, such as β-adrenergic receptors, can modulate the induction and expression of LTD. The specific mechanisms by which noradrenaline affects LTD are not fully understood.
Endocannabinoids: Endocannabinoids are endogenous cannabinoids that act as retrograde messengers in the brain. They are involved in the regulation of synaptic transmission and plasticity. Activation of cannabinoid receptors, particularly CB1 receptors, can modulate LTD. Endocannabinoids can be released from postsynaptic neurons and act on presynaptic cannabinoid receptors to suppress neurotransmitter release, leading to the expression of LTD.
Neuromodulators: Various neuromodulators, such as dopamine, serotonin and noradrenaline, can modulate the induction and expression of LTD. These neuromodulators often act through G-protein coupled receptors and can either facilitate or inhibit LTD, depending on the specific receptors and signaling pathways involved .
Synaptic tagging and capture: Synaptic tagging and capture is a mechanism that allows the selective stabilization of synaptic changes induced by specific patterns of activity. This mechanism can modulate LTD by determining which synapses undergo long-lasting weakening and which ones are spared.
Protein synthesis: The synthesis of new proteins is essential for the expression of LTD. Modulation of protein synthesis through factors like transcription factors and translation regulators can influence the magnitude and persistence of LTD.
Glutamate: Glutamate is the primary excitatory neurotransmitter in the central nervous system and plays a central role in synaptic plasticity. Activation of glutamate receptors, particularly the metabotropic Glutamate Receptors (mGluRs), can induce LTD. The activation of specific mGluR subtypes, such as mGluR1 and mGluR5, can trigger signaling pathways that lead to the suppression of synaptic strength and the expression of LTD .
Dopamine: Dopamine is a neuromodulator involved in reward, motivation and movement. It can modulate synaptic plasticity, including LTD, in several brain regions. Dopamine receptors, particularly D1-like receptors, are known to be involved in the induction and expression of LTD. Activation of D1-like receptors can initiate signaling cascades that ultimately lead to the suppression of synaptic transmission and the expression of LTD.
Serotonin: Serotonin, or 5-Hydroxy Tryptamine (5-HT), is a neurotransmitter involved in mood regulation, sleep and various other physiological processes. Serotonin can modulate synaptic plasticity and regulate LTD in several brain areas. Activation of specific serotonin receptor subtypes, such as 5-HT1A and 5-HT2A receptors, can affect the induction and expression of LTD. The exact mechanisms by which serotonin modulates LTD are still being studied .
These are just a few examples of neurotransmitters and neuromodulators that can modulate long-term depression. It's important to note that the modulation of LTD by these substances can vary depending on the brain region, specific receptors involved and other factors. The interplay between different neurotransmitters and neuromodulators contributes to the complex regulation of synaptic plasticity and the finetuning of brain function.
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