Molecular Markers in Neuroplasticity Research: BDNF/TrkB, CREB Phosphorylation, and Synaptic Protein Detection

Neuroplasticity research requires simultaneous evaluation of neurotrophic signaling, transcriptional regulation, and synaptic structural changes. BDNF/TrkB reflects neurotrophin-mediated synaptic regulation. CREB phosphorylation reflects activity-dependent transcriptional initiation. Synaptic proteins such as Synaptophysin, Synapsin I, PSD95, GluA1, and Synaptotagmin are used to assess presynaptic release, postsynaptic density organization, and excitatory synaptic remodeling.

Keywords: neuroplasticity; BDNF; TrkB; CREB; synaptic proteins; PSD95; Synaptophysin; neuronal synapse

1 Research Logic of Molecular Markers in Neuroplasticity

1.1 Molecular levels of neuroplasticity

(1) Neurotrophin level

BDNF is one of the most commonly used neurotrophin markers in neuroplasticity research. It can regulate neuronal survival, dendritic development, axonal growth, synapse formation, and long-term potentiation. After BDNF binds to TrkB, it can activate downstream pathways such as PI3K-Akt, Ras-MAPK/ERK, and PLCγ-Ca²⁺, thereby promoting enhanced synaptic function and activity-dependent gene expression.

(2) Transcriptional regulation level

CREB is an important transcription factor that links neural activity with gene expression. Total CREB protein expression may not change markedly, so p-CREB is more commonly detected in research, especially phosphorylation at Ser133. Increased p-CREB usually indicates that neural activity, Ca²⁺ signaling, cAMP/PKA, ERK, or CaMK pathways have entered the stage of nuclear transcriptional regulation.

(3) Synaptic structure and function level

Synaptic proteins reflect the terminal execution state of neuroplasticity. Synaptophysin, Synapsin I, SNAP25, and Synaptotagmin are more associated with presynaptic vesicle reserve, release, and presynaptic terminal density. PSD95, Homer1, Shank, GluA1, and GluN2B are more associated with the postsynaptic density, excitatory synapse maturation, and receptor-composition changes.

1.2 Relationships among molecular markers

(1) BDNF/TrkB and synaptic proteins

BDNF-TrkB signaling can promote synapse formation and synaptic protein expression and is often accompanied by increased expression of PSD95, Synaptophysin, Synapsin I, or GluA1. However, increased BDNF does not necessarily mean enhanced synaptic function. Synaptic proteins, dendritic spine density, electrophysiology, or behavioral results should be combined for interpretation.

(2) CREB and BDNF expression

CREB can regulate transcription of activity-dependent genes such as BDNF. After p-CREB increases, BDNF mRNA or protein may be upregulated in a later time window. If only a single time point is detected, p-CREB may have already returned to baseline while BDNF remains elevated, or p-CREB may increase before BDNF protein changes are detectable.

(3) Synaptic proteins and functional readouts

Changes in synaptic proteins can indicate synaptic structural or functional status, but they cannot fully replace electrophysiology, calcium imaging, or behavioral evaluation. Increased PSD95 may suggest enhancement of the postsynaptic density, and increased Synaptophysin may suggest increased presynaptic terminal density. Whether these changes translate into effective synaptic transmission still requires functional assays.

Table 1 Common Molecular Marker Framework for Neuroplasticity Research

Analysis Level	Core Markers	Recommended Methods	Interpretation Focus
Neurotrophins	BDNF, proBDNF, mature BDNF	ELISA, Western blot, qPCR, IF/IHC	Distinguish functional differences between mature BDNF and proBDNF
Receptor activation	TrkB, p-TrkB, p75NTR	Western blot, IF, IHC	Focus on TrkB phosphorylation rather than total TrkB alone
Downstream signaling	p-Akt, p-ERK, p-PLCγ, p-CaMKII	Western blot, IF	Determine whether BDNF/TrkB signaling is truly activated
Transcriptional regulation	CREB, p-CREB, c-Fos, Arc, Egr1	Western blot, IF, qPCR	p-CREB and immediate early genes indicate activity-dependent transcription
Presynaptic proteins	Synaptophysin, Synapsin I, SNAP25, Synaptotagmin	Western blot, IF, IHC	Reflect vesicle reserve, presynaptic terminal density, and release-related status
Postsynaptic proteins	PSD95, Homer1, Shank, GluA1, GluN2B	Western blot, IF, IHC	Reflect postsynaptic density and excitatory synapse maturation
Structural plasticity	MAP2, NeuN, DCX, GAP43	IF, IHC, Western blot	Interpret together with dendritic, neurogenesis, and axonal growth markers
Functional validation	LTP, mEPSC, Ca²⁺ imaging, behavior	Electrophysiology, calcium imaging, behavioral tests	Link molecular changes with functional plasticity

2 BDNF/TrkB Signaling and Neuroplasticity

2.1 Detection significance of BDNF

(1) Neurotrophic support

BDNF promotes neuronal survival, neurite outgrowth, and synapse formation. It is a core molecule in studies of learning and memory, emotional regulation, neural injury repair, and neurodegenerative diseases. The hippocampus, prefrontal cortex, amygdala, and striatum are often key brain regions in BDNF-related plasticity studies.

(2) Mature BDNF and proBDNF

BDNF is synthesized as the precursor proBDNF and is processed into mature BDNF by intracellular or extracellular proteases. Mature BDNF mainly promotes synaptic enhancement and neuronal survival through TrkB. proBDNF can participate in synaptic weakening, apoptosis, or structural pruning through p75NTR-related pathways. For studies focused on plasticity direction, proBDNF and mature BDNF should be distinguished whenever possible, rather than detecting total BDNF only.

(3) Expression and release differences

BDNF mRNA, intracellular BDNF protein, and secreted BDNF are not completely equivalent. qPCR reflects transcriptional levels. Western blot reflects protein abundance in tissue or cell lysates. ELISA can quantify BDNF levels in tissue homogenates, serum, cerebrospinal fluid, or culture supernatants. If activity-dependent release is the focus, culture supernatants or synapse-related fractions should be prioritized.

2.2 TrkB receptor activation

(1) Total TrkB and p-TrkB

TrkB is the high-affinity receptor for BDNF. Total TrkB expression reflects receptor abundance, whereas p-TrkB more directly represents receptor activation. If BDNF increases but p-TrkB remains unchanged, this may indicate ineffective activation of the receptor, abnormal receptor localization, inappropriate sampling time, or the presence of negative regulatory mechanisms.

(2) Downstream pathway branches

After TrkB activation, multiple signaling branches can be triggered. PI3K-Akt is related to neuronal survival and protein synthesis. MAPK/ERK is related to transcriptional regulation and synaptic enhancement. The PLCγ-Ca²⁺ pathway can connect CaMK, CREB, and synaptic activity. Downstream markers should be selected according to the research question rather than detecting only BDNF or TrkB.

(3) Receptor localization

TrkB function depends on membrane localization, endocytosis, and axonal/dendritic transport. Immunofluorescence or subcellular fractionation can help determine whether TrkB is localized to synaptic regions. If total protein changes are not obvious but TrkB or p-TrkB increases in synaptic fractions, this may better reflect local synaptic plasticity changes.

2.3 Interpretation of BDNF/TrkB results

(1) Time window

BDNF mRNA, BDNF protein, p-TrkB, and synaptic protein changes occur in different time windows. After acute stimulation, p-TrkB and p-CREB can change rapidly, whereas BDNF protein and synaptic proteins usually require a longer period. Experiments should include early signaling time points and later structural time points according to the model.

(2) Brain-region specificity

BDNF/TrkB signaling shows clear brain-region specificity. Increased BDNF in the hippocampus is often associated with learning, memory, and LTP. BDNF changes in the prefrontal cortex and amygdala may be related to emotion, stress, and fear memory. TrkB signaling in the striatum may involve motor learning and reward-related plasticity. Whole-brain homogenates can easily mask region-specific changes.

(3) Differences among pathological models

BDNF/TrkB changes do not follow the same direction in chronic stress, Alzheimer’s disease, Parkinson’s disease, cerebral ischemia, epilepsy, and neural injury models. In some models, increased BDNF may be a compensatory response, while in others it may represent plasticity recovery after therapeutic intervention. Interpretation should incorporate neuronal injury, inflammation, synaptic proteins, and behavioral indicators.

Table 2 BDNF/TrkB Signaling Detection Markers and Interpretation

Marker	Molecular Meaning	Common Methods	Interpretation Notes
BDNF mRNA	BDNF transcription level	qPCR, RNA-seq	Does not directly represent protein secretion or receptor activation
proBDNF	BDNF precursor form	Western blot, ELISA, IF	May be related to p75NTR-associated pathways and synaptic pruning
mature BDNF	Mature neurotrophic factor	Western blot, ELISA, IF	More directly associated with TrkB activation and synaptic enhancement
total TrkB	Total receptor abundance	Western blot, IF, IHC	Expression level does not equal activation status
p-TrkB	TrkB activation status	Western blot, IF	Sampling time and phosphoprotein preservation must be controlled
p-Akt	Survival- and protein synthesis-related branch	Western blot	Related to TrkB activation but not completely specific
p-ERK	Activity-dependent transcription and plasticity signaling	Western blot, IF	Can be interpreted together with p-CREB and Arc
p-PLCγ	TrkB-Ca²⁺ signaling branch	Western blot	Suitable for analyzing TrkB downstream Ca²⁺-related mechanisms

3 CREB Phosphorylation and Activity-Dependent Transcription

3.1 Functional positioning of CREB

(1) Transcription factor hub

CREB is an important transcription factor where neural activity, cAMP, Ca²⁺, ERK, and PKA signals converge. After activation, CREB can regulate the expression of BDNF, c-Fos, Arc, Egr1, and other plasticity-related genes, participating in long-term memory formation and synaptic structural remodeling.

(2) p-CREB is more informative for activation

Total CREB protein is usually relatively stable, while p-CREB better reflects signaling activation. Phosphorylation at Ser133 is the most commonly used marker of CREB activation. If total CREB remains unchanged but p-CREB increases, this usually indicates enhanced transcriptional activity. If total CREB decreases, neuronal injury or changes in cellular composition should be further evaluated.

(3) Nuclear localization

As a transcription factor, CREB functions in the nucleus. When p-CREB is detected by immunofluorescence, nuclear signal should be emphasized rather than only comparing total fluorescence intensity. In brain tissue sections, co-staining with NeuN, MAP2, or nuclear dyes can help clarify whether p-CREB originates from neurons or other cell types.

3.2 Upstream regulation of CREB

(1) BDNF/TrkB-ERK-CREB

After BDNF activates TrkB, the Ras-MAPK/ERK pathway can promote CREB phosphorylation. If the intervention group shows simultaneous increases in p-TrkB, p-ERK, and p-CREB, together with improvement in BDNF or synaptic proteins, this more strongly supports BDNF/TrkB-mediated enhancement of plasticity.

(2) Ca²⁺/CaMK-CREB

Enhanced neural activity, NMDA receptor activation, and calcium influx can activate kinases such as CaMKII and CaMKIV, further promoting CREB phosphorylation. In learning and memory, LTP, epileptic activity, and neural stimulation models, the Ca²⁺-CaMK-CREB axis is often closely related to synaptic plasticity.

(3) cAMP/PKA-CREB

Dopamine, norepinephrine, adenosine, and some GPCR signals can regulate CREB through cAMP/PKA. In studies related to emotion, addiction, reward learning, and sleep-wake regulation, cAMP/PKA-CREB crosstalk with BDNF/TrkB signaling should be considered.

3.3 CREB detection and interpretation

(1) Time dependence

p-CREB is often a rapid and dynamic marker. It can change markedly within minutes to hours after stimulation and may later return to baseline. If sampling is too late, p-CREB may have declined while BDNF or synaptic proteins remain upregulated. Therefore, CREB detection should include earlier time points.

(2) Cell-type source

p-CREB can occur in neurons as well as glial cells. In neuroplasticity research, co-staining with NeuN, MAP2, GFAP, or Iba1 should be used to determine the signal source. If p-CREB increases in glial cells, the result may be more related to inflammation or repair responses rather than purely neuronal synaptic plasticity.

(3) Combination with immediate early genes

c-Fos, Arc, and Egr1 are commonly used activity-dependent immediate early genes. Simultaneous increases in p-CREB and c-Fos or Arc can strengthen the interpretation of neural activity and synaptic plasticity-related transcriptional initiation. If p-CREB increases but Arc remains unchanged, this may indicate insufficient signal intensity, mismatched time points, or blocked downstream transcriptional regulation.

Table 3 CREB-Related Detection Markers and Experimental Interpretation

Marker	Main Significance	Common Methods	Interpretation Focus
total CREB	Total CREB protein level	Western blot, IF, IHC	Usually used as the normalization basis for p-CREB
p-CREB Ser133	CREB activation status	Western blot, IF, IHC	Focus on nuclear signal and sampling time
p-ERK	MAPK pathway activation	Western blot, IF	Can connect BDNF/TrkB with CREB
p-CaMKII	Ca²⁺-dependent synaptic signaling	Western blot, IF	Often related to LTP and NMDA receptor activity
PKA substrate	cAMP/PKA pathway activity	Western blot	Suitable for GPCR-cAMP-CREB-related models
c-Fos	Immediate early gene of neuronal activity	IF, IHC, qPCR	Reflects neuronal activation but is not synapse-specific
Arc	Activity-dependent synaptic plasticity gene	qPCR, Western blot, IF	Closely related to learning, memory, and synaptic remodeling
Egr1	Immediate early transcription factor	qPCR, Western blot, IF	Can serve as an auxiliary marker of CREB-related transcriptional responses

4 Synaptic Protein Detection and Synaptic Structural Plasticity

4.1 Presynaptic proteins

(1) Synaptophysin

Synaptophysin is a synaptic vesicle membrane protein and is commonly used as a marker of presynaptic terminal density and synaptic vesicle-related structures. Increased Synaptophysin usually suggests an increase in presynaptic structures or vesicle-associated protein expression, but it does not directly indicate increased release probability.

(2) Synapsin I

Synapsin I is associated with the synaptic vesicle reserve pool and vesicle mobilization. Total Synapsin I reflects vesicle-related structural status, while p-Synapsin I more closely reflects activity-dependent regulation of vesicle release. If presynaptic function is being studied, Synapsin I phosphorylation should be prioritized together with total Synapsin I.

(3) SNAP25 and Synaptotagmin

SNAP25 is a SNARE complex-related protein involved in synaptic vesicle fusion. Synaptotagmin is a Ca²⁺-dependent release sensor. Changes in these two proteins are more closely related to the state of the synaptic release machinery and can be used to analyze presynaptic functional regulation, neurotoxic injury, or abnormal synaptic release.

4.2 Postsynaptic proteins

(1) PSD95

PSD95 is a core scaffold protein of the excitatory postsynaptic density and is commonly used to evaluate postsynaptic structural maturation and excitatory synaptic stability. Increased PSD95 usually suggests enhancement of the postsynaptic density, but functional significance should be interpreted together with dendritic spine density, GluA1/GluN2B, or electrophysiological results.

(2) Homer1 and Shank

Homer1 and Shank are important members of the postsynaptic scaffold complex, connecting glutamate receptors, the cytoskeleton, and signaling molecules. They are suitable for studying excitatory synaptic structural remodeling, neurodevelopmental disorders, addiction, learning and memory, and chronic stress models.

(3) GluA1 and GluN2B

GluA1 is an AMPA receptor subunit, and GluN2B is an NMDA receptor subunit. Enhanced surface expression or synaptic membrane localization of GluA1 is often associated with enhanced excitatory transmission. GluN2B changes may relate to developmental stage, synaptic plasticity, and excitotoxicity. In addition to total protein detection, membrane protein fractionation or immunofluorescence localization analysis can be added.

4.3 Synaptic protein detection strategies

(1) Whole-tissue lysate detection

Western blot detection of whole-tissue lysates is suitable for observing overall expression changes, but it cannot distinguish synaptic regions, soma regions, and different cellular sources. When brain regions are large or cell types are complex, whole-tissue results may be diluted.

(2) Synaptosome or synaptic fraction detection

Synaptosome isolation, PSD fraction extraction, or membrane protein fractionation can improve synapse-specific interpretation. If synaptic structural plasticity is the focus, changes in PSD95, Synaptophysin, GluA1, or p-TrkB in synaptic fractions are usually more informative than whole-tissue detection.

(3) Immunofluorescence localization

Immunofluorescence can be used to observe synaptic protein puncta density, co-localization, and cellular distribution. Co-localization of PSD95 and Synaptophysin can be used to infer excitatory synaptic structures, but it remains morphological evidence. Electrophysiology or calcium imaging should be combined if enhanced synaptic transmission needs to be demonstrated.

Table 4 Common Synaptic Protein Markers and Plasticity Interpretation

Marker	Main Localization	Molecular Significance	Interpretation Notes
Synaptophysin	Presynaptic vesicles	Presynaptic terminals and vesicle density	Does not directly equal release function
Synapsin I	Presynaptic vesicle reserve pool	Vesicle reserve and mobilization	p-Synapsin I is closer to activity-dependent changes
SNAP25	Presynaptic release machinery	SNARE-related vesicle fusion	Related to release function but requires functional experiments
Synaptotagmin	Presynaptic Ca²⁺ sensor	Ca²⁺-dependent vesicle release	Suitable for analyzing release abnormalities and presynaptic function
PSD95	Postsynaptic density	Excitatory synapse maturation and stability	Recommended to combine with GluA1/GluN2B or dendritic spine analysis
Homer1	Postsynaptic scaffold	Links mGluR and PSD structures	Closely related to activity-dependent plasticity
Shank	Postsynaptic scaffold	PSD structural stability and receptor-complex organization	Commonly used in neurodevelopmental and psychiatric disease models
GluA1	AMPA receptor subunit	Enhanced excitatory synaptic transmission	Surface expression and synaptic localization are more important than total amount
GluN2B	NMDA receptor subunit	Plasticity, development, and excitotoxicity-related	Must be interpreted according to brain region, age, and pathological background
Gephyrin	Inhibitory postsynaptic structure	Stability of GABAergic synapses	Can be used with PSD95 to distinguish excitatory/inhibitory balance

5 Selection of Reagents and Materials for Neuroplasticity Research

Table 5 BDNF/TrkB Signaling-Related Product Selection

Application Module	Cat. No.	Product Name	Grade/Specification	System Positioning
BDNF protein detection	Ab090903	BDNF Antibody	ExactAb™, Validated, 1.0 mg/mL	Used for detecting BDNF protein expression by Western blot, IF/IHC, and related methods
BDNF gene intervention	B1479025	BDNF Human Pre-designed siRNA Set A		Used for BDNF knockdown in human cells to validate regulation of synaptic proteins and CREB signaling by BDNF
BDNF KO control	P744139	pLenti-BDNF-sgRNA		Used for BDNF antibody specificity validation and KO protein control
BDNF KO control	P744140	pLenti-BDNF-sgRNA		Used for BDNF mRNA-level KO control validation
BDNF gene intervention	B1475929	Bdnf Mouse Pre-designed siRNA Set A		Used for Bdnf knockdown studies in mouse-derived cells or models
BDNF quantitative detection	H1128695	Human BDNF ELISA Kit	Bioactive, for enzyme immunoassay(ELISA), for ELISA	Used for quantitative detection of BDNF levels in human samples
BDNF mimetic	L276057	LM22A-4	≥98%	Used to mimic BDNF/TrkB-related neurotrophic signaling; suitable for mechanistic intervention experiments
BDNF protein stimulation	rp143209-GMP	Recombinant Human BDNF GMP Protein	Animal Free,Carrier Free,Bioactive,ActiBioPure™,High Performance,sterile,≥70%(SDS-PAGE)	Used for human BDNF stimulation, neuronal culture, and TrkB activation experiments
BDNF protein stimulation	rp330087	Recombinant Mouse BDNF Protein	≥90%(SDS-PAGE)	Used for BDNF stimulation and neuroplasticity experiments in mouse systems
BDNF protein stimulation	rp330088	Recombinant Rat BDNF Protein	≥90%(SDS-PAGE)	Used for BDNF stimulation and neuronal model experiments in rat systems
proBDNF quantification	EJ1513881	Human pro-Brain Derived Neurotrophic Factor (proBDNF) ELISA Kit	BioReagent	Used to distinguish proBDNF from mature BDNF; suitable for analyzing synaptic pruning or injury models
mature BDNF quantification	EJ1514120	Human Mature Brain-derived Neurotrophic Factor(mBDNF) ELISA Kit	BioReagent	Used to detect mature BDNF and evaluate TrkB-related pro-plasticity signaling
BDNF quantification	EJ1514761	Human Brain Derived Neurotrophic Factor (BDNF) ELISA Kit	BioReagent	Used for BDNF quantification in human tissue, serum, cerebrospinal fluid, or cell supernatant
BDNF quantification	H1509869	Human BDNF ELISA Kit	BioReagent	Used to detect human BDNF levels and can complement WB or qPCR results
BDNF quantification	EJ1512285	Rat Brain Derived Neurotrophic Factor (BDNF) ELISA Kit	BioReagent	Used for BDNF quantification in rat neuroplasticity models
BDNF quantification	R1509870	Rat BDNF ELISA Kit	BioReagent	Used to detect BDNF levels in rat samples
proBDNF quantification	EJ1512686	Mouse pro-Brain Derived Neurotrophic Factor (proBDNF) ELISA Kit	BioReagent	Used to detect proBDNF in mouse models
mature BDNF quantification	EJ1512794	Mouse Mature Brain-derived Neurotrophic Factor (mBDNF) ELISA Kit	BioReagent	Used to detect mature BDNF in mouse models
BDNF quantification	EJ1513155	Mouse Brain Derived Neurotrophic Factor (BDNF) ELISA Kit	BioReagent	Used for BDNF quantification in mouse tissue or cell samples
BDNF quantification	M1509871	Mouse BDNF ELISA Kit	BioReagent	Used to detect mouse BDNF expression levels
TrkB antagonism	A168673	ANA-12	≥96%	Used to block TrkB signaling and validate dependence of BDNF/TrkB on CREB and synaptic proteins
TrkB activation	H287399	HIOC	≥98%(HPLC)	Used to activate TrkB-related signaling and analyze p-CREB and synaptic protein changes
TrkB protein/control	rp181612	Recombinant Human TrkB Protein	Animal Free,Carrier Free,Bioactive,ActiBioPure™,His Tag,PBS Only,≥95%(SDS-PAGE)	Used for TrkB antibody validation, ligand binding, or in vitro functional studies
TrkB detection	Ab132585	Recombinant TrkB Antibody	Recombinant, ExactAb™, Validated, High Performance, See COA	Used to detect total TrkB protein expression
TrkB detection/blocking	Ab209857	Rinat patent anti-TrkB (anti-TrkB)	Carrier Free, Recombinant, ExactAb™, Low Endotoxin, Azide Free, Validated, Animal Free, ≥95%(SDS-PAGE&SEC-HPLC), See COA	Can be used for TrkB detection or TrkB-related functional intervention studies
TrkB inhibition	T1447293	TrkB-IN-1		Used for TrkB pathway inhibition to verify dependence of downstream BDNF/TrkB signaling
TrkB quantification	EJ1513913	Human Tropomyosin Receptor Kinase B (TrkB) ELISA Kit	BioReagent	Used to detect TrkB levels in human samples
TrkB quantification	EJ1513312	Mouse TrkB Tyrosine Kinase (TrkB) ELISA Kit	BioReagent	Used to detect TrkB levels in mouse samples

Table 6 CREB, Immediate Early Gene, and Transcriptional Regulation-Related Product Selection

Application Module	Cat. No.	Product Name	Grade/Specification	System Positioning
CREB inhibition	C1429634	CREB-IN-1 TFA		Used to inhibit CREB-related transcriptional activity and validate the effect of p-CREB/CREB on BDNF and synaptic protein expression
CREB1 gene intervention	C1490830	CREB1 Human Pre-designed siRNA Set A		Used for CREB1 knockdown in human cells to analyze CREB-dependent plasticity-related transcription
CREB1 detection	Ab326117	CREB1 Mouse mAb	KD Validation	Used for CREB1 protein detection and knockdown validation
CREB1 detection	Ab325768	CREB1 Mouse mAb	KO Validation	Used for CREB1 protein detection and KO validation
CREB1 KO control	P745029	pLenti-CREB1-sgRNA		Used for CREB1 antibody specificity validation and KO protein control
CREB1 KO control	P745030	pLenti-CREB1-sgRNA		Used for CREB1 mRNA-level KO control validation
CREB detection	Ab097670	Recombinant CREB Antibody	ExactAb™, Validated, Recombinant, 0.2 mg/mL	Used to detect total CREB protein; suitable as the normalization basis for p-CREB
CREB detection	Ab222289	Recombinant CREB Antibody	Recombinant, ExactAb™, Validated, See COA	Used for total CREB protein detection
CREB1 detection	Ab326870	Recombinant CREB1 Antibody	KD Validation	Used for protein validation in CREB1 knockdown experiments
CREB1 detection	Ab326868	Recombinant CREB1 Antibody	KD Validation	Used for CREB1 protein detection and knockdown validation
CREB binding detection	E745603	EMSA Probe CREB	1.75μM	Used to detect CREB-DNA binding activity
CREB binding detection	E745604	EMSA Probe CREB	10μM	Used for CREB-DNA binding assays and transcription factor activity analysis
CREB binding control	M745633	Mutant EMSA Probe CREB	1.75μM	Used as a specificity control for CREB EMSA
CREB binding control	M745634	Mutant EMSA Probe CREB	10μM	Used as a mutant probe control for CREB EMSA
CREB binding detection	B752128	Biotin-labeled EMSA probe-CREB	0.2μM	Used for non-radioactive EMSA detection of CREB DNA-binding activity
CREB substrate/methodology	C333559	CREBtide TFA	≥98%	Used for CREB-related kinase activity or substrate phosphorylation studies
CREBBP auxiliary transcriptional regulation	C1484421	CREBBP Human Pre-designed siRNA Set A		Used for CREBBP knockdown to analyze CREB-mediated transcriptional coactivation mechanisms
CREBBP detection	Ab097687	CREBBP Antibody	ExactAb™, Validated, See COA	Used to detect CREBBP protein; suitable for CREB transcriptional coactivation studies
CREBBP protein/control	rp329704	Recombinant Human CREBBP Protein	≥90%(SDS-PAGE)	Used for CREBBP-related methodological validation
CREB pathway activation	P656344	PI3K/Akt/CREB activator 1	10mM in DMSO	Used to activate PI3K/Akt/CREB-related signaling and analyze plasticity-related transcriptional responses
CREB pathway activation	P650618	PI3K/Akt/CREB activator 1	≥99%	Used for CREB-related pathway activation and mechanistic validation
Immediate early gene detection	Ab156213	c-Fos Mouse mAb	Carrier Free,ExactAb™,Azide Free,Validated,High Performance,PBS Only,≥95%(SDS-PAGE),1.0 mg/mL	Used to detect c-Fos and evaluate activity-dependent immediate early responses
Immediate early gene detection	Ab096159	c-Fos Mouse mAb	ExactAb™, Validated, 1.0 mg/mL	Used for c-Fos protein detection and neuronal activity marker analysis
c-Fos protein/control	rp170130	Recombinant Human c-Fos Protein	Carrier Free,Azide Free,His Tag,≥90%(SDS-PAGE)	Used for c-Fos antibody validation or as a standard
Arc detection	Ab089453	ARC Antibody	See COA	Used to detect Arc and evaluate activity-dependent synaptic plasticity gene expression
Arc gene intervention	A1463420	ARC Human Pre-designed siRNA Set A		Used to knock down ARC and analyze the role of Arc in synaptic remodeling
Arc KO control	P743861	pLenti-ARC-sgRNA		Used for ARC antibody specificity validation and KO protein control
Arc KO control	P743862	pLenti-ARC-sgRNA		Used for ARC mRNA-level KO control
EGR1 gene intervention	E1490363	EGR1 Human Pre-designed siRNA Set A		Used to knock down EGR1 and analyze activity-dependent early transcriptional responses
EGR1 KO control	P745543	pLenti-EGR1-sgRNA		Used for EGR1 antibody specificity validation and KO control
EGR1 KO control	P745544	pLenti-EGR1-sgRNA		Used for EGR1 transcription-level KO control
EGR1 detection	Ab101195	Recombinant Egr1 Antibody	ExactAb™, Validated, Recombinant, 1.11 mg/mL	Used for EGR1 protein detection
EGR1 quantification	EJ1514178	Human Early Growth Response Protein 1 (EGR1) ELISA Kit	BioReagent	Used to detect EGR1 levels in human samples
EGR1 quantification	EJ1512821	Mouse Early Growth Response Protein 1 (EGR1) ELISA Kit	BioReagent	Used to detect EGR1 levels in mouse samples

6 Common Questions

6.1 Does increased BDNF necessarily indicate enhanced neuroplasticity?

Not necessarily. Increased BDNF may indicate enhanced neurotrophic support, but it may also be a compensatory response after injury, stress, or inflammation. p-TrkB, p-CREB, synaptic proteins, neuronal structure, and functional experiments should be interpreted together.

6.2 Why is it necessary to distinguish proBDNF from mature BDNF?

proBDNF and mature BDNF may have different or even opposite functional directions. Mature BDNF mainly promotes synaptic enhancement and neuronal survival through TrkB, whereas proBDNF may participate in synaptic pruning, apoptosis, or injury-related responses through p75NTR. Detecting only total BDNF can easily lead to misinterpretation.

6.3 How should p-CREB and total CREB be analyzed together?

p-CREB reflects CREB activation status, while total CREB reflects total CREB abundance. The p-CREB/CREB ratio is usually calculated and then normalized to a loading control or total protein as needed. If total CREB itself changes markedly, the influence of altered transcription factor abundance should be explained.

6.4 Why does p-CREB increase while synaptic proteins remain unchanged?

p-CREB is an early signal, whereas synaptic protein changes usually occur later. The detection time may be too early, or CREB activation may be insufficient to trigger structural synaptic changes. Additional time points for Arc, c-Fos, BDNF, and later synaptic proteins should be included.

6.5 Should PSD95 and Synaptophysin be detected simultaneously?

Yes. PSD95 represents the postsynaptic density, while Synaptophysin represents presynaptic vesicle-related structures. Detecting both provides a better assessment of synaptic structural integrity and pre-/postsynaptic matching.

BDNF/TrkB, CREB, and synaptic proteins correspond to neurotrophic signaling, activity-dependent transcription, and the synaptic structural execution layer, respectively. Reliable neuroplasticity research should not rely on a single marker. Instead, BDNF/TrkB activation, nuclear p-CREB signaling, pre- and postsynaptic proteins, brain-region localization, and functional validation should be integrated to build a complete chain of evidence from molecular signaling to synaptic structure and neural function.