Rolipram (GMP)

By lysing cells, releasing RNA, and removing impurities such as proteins and DNA, high-purity RNA products are finally obtained. The commonly used traditional method is the guanidine isothiocyanate/phenol/chloroform method (Trizol), which is suitable for a variety of animal materials including animal tissues, microorganisms, cultured cells, etc., and most plant materials.

Live/dead viability and cytotoxicity staining assays are based on the simultaneous detection of intracellular esterase activity in metabolically active (viable) cells and membrane integrity loss in non-viable cells. In commonly used dual-staining approaches, membrane-permeant fluorogenic substrates are converted by intracellular esterases into fluorescent products in live cells, while impermeant DNA-binding dyes selectively enter cells with compromised plasma membranes and label nucleic acids in dead or dying cells, enabling discrimination between viable and non-viable populations by fluorescence microscopy or flow cytometry.

The Morris Water Maze is a rodent spatial learning and memory assay in which a mouse or rat swims in opaque water to find an escape platform; in the hidden-platform version, the animal cannot see the platform and must use distal extra-maze cues to learn its fixed spatial location. The assay primarily measures hippocampus-dependent spatial learning during acquisition trials and spatial reference memory during probe trials after platform removal; readouts include escape latency, swim path length, swim speed, quadrant occupancy, platform-site crossings, and proximity to the former platform location.

Cell differentiation refers to the process in which cells of the same origin gradually produce cell groups with different morphological structure and functional characteristics.

PC12 cells are a rat adrenal pheochromocytoma-derived clonal cell line that responds to nerve growth factor by stopping proliferation and extending neurites, producing a sympathetic neuron-like phenotype used to study neuronal differentiation and neurite outgrowth. NGF acts through TrkA-dependent signaling, and neurite outgrowth is associated with ERK/Akt signaling, microtubule organization, neuronal-marker expression, and increased electrophysiological neuronal features such as sodium-channel density. The main assay readout is morphological differentiation, usually measured as the percentage of neurite-bearing cells, neurite length, neurite number, or total neurite length per cell. Additional readouts include GAP-43, tyrosine hydroxylase, βIII-tubulin, neurofilament, synapsin I, synaptophysin, ERK phosphorylation, Akt phosphorylation, and sodium-channel current density.

PINK1/Parkin-mediated mitophagy pathway is a mitochondrial quality-control signaling axis in which mitochondrial depolarization stabilizes PINK1 on damaged mitochondria, activates Parkin recruitment and E3 ubiquitin ligase activity, promotes ubiquitination of outer mitochondrial membrane proteins, recruits selective autophagy adaptors, and drives lysosomal degradation of damaged mitochondria. In neurological disease research, this pathway is experimentally important because neurons, especially dopaminergic neurons, are highly dependent on mitochondrial integrity, and defective mitochondrial turnover can lead to mitochondrial dysfunction, oxidative stress, impaired neuronal survival, α-synuclein accumulation, and neuroinflammatory damage-associated signals. The genetic disease link is strongest in Parkinson’s disease because mutations in PRKN/parkin cause autosomal recessive juvenile parkinsonism, mutations in PINK1 cause hereditary early-onset Parkinson’s disease, and Drosophila studie

Congo red amyloid staining is a histochemical method used to detect extracellular amyloid deposits in tissue sections based on the affinity of Congo red dye for β-pleated sheet-rich protein aggregates. When bound to amyloid, Congo red produces characteristic apple-green birefringence under polarized light microscopy, which is widely regarded as a diagnostic feature of amyloid deposition in histopathology. The diagnostic principle relies on the combination of dye binding (congophilia) and optical anisotropy under polarized illumination, which distinguishes amyloid from most non-amyloid eosinophilic extracellular deposits in routine histological evaluation. Amyloid identification by Congo red staining remains a cornerstone in diagnostic pathology despite the availability of adjunct methods such as immunohistochemistry and mass spectrometry, particularly because of its ability to localize deposits directly within tissue architecture. The specificity of Congo red-positive deposits is incre

Directly induced neuron culture converts somatic cells, most commonly fibroblasts, into induced neurons without passing through a pluripotent or neural progenitor stage; classic evidence shows that mouse fibroblasts can be converted by Ascl1, Brn2/Pou3f2, and Myt1l, human fibroblasts can be converted by defined neuronal transcription factors, and human fibroblasts can also be converted by miR-9/9-124 with neurogenic or subtype-specifying transcription factors. The readout is acquisition of neuronal identity and function, assessed by neuronal morphology, neuronal markers such as Tuj1/βIII-tubulin, MAP2, synapsin, and subtype markers when relevant, together with functional assays such as action-potential firing, synaptic activity, and electrophysiology.

The following protocol uses the MTT colorimetric assay as a classic literature-established method for assessing cell viability/metabolic activity in cultured mammalian cells. MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] is reduced by metabolically active cells to a colored formazan product; the amount of formazan is quantified spectrophotometrically and provides an indirect measure of metabolically active viable cells. Importantly, MTT reduction reflects cellular oxidoreductase/metabolic activity rather than an absolute direct count of living cells, so changes in cellular metabolism can alter the signal independently of cell number.

Alzheimer’s Disease (AD) is a neurodegenerative disorder characterized by a progressive decline in cognitive functions and loss of specific types of neurons and synapses. Alzheimer's symptoms can be simulated in mice by injecting drugs (such as Aβ) or genetically modified.

PC12 cells are a rat adrenal pheochromocytoma clonal line that responds to NGF by stopping proliferation and extending branching neurite-like processes; after longer NGF exposure, cells develop long processes and neuronal-like ultrastructural and functional features. NGF-induced differentiation is read out mainly by neurite outgrowth, reduced proliferation, microtubule assembly, and neuronal differentiation-associated proteins such as MAPs, tau, GAP-43, and synapsin-1.

The Shuttle Box Test for TDPA, or temporally dissociated passive avoidance, measures hippocampus-dependent associative learning by testing whether a rodent avoids entering a dark compartment that was previously paired with foot shock after a temporal delay between dark-compartment entry and shock delivery. The main behavioral readout is crossover or step-through latency from the light chamber into the dark chamber; increased latency across training or retention trials reflects learned avoidance memory rather than motor performance alone.

iPSC/hPSC-derived neuron differentiation culture directs pluripotent cells toward neuroectoderm and then neuronal lineages by suppressing developmental signals that maintain non-neural fates; the classic monolayer dual-SMAD approach blocks BMP and Activin/TGF-β signaling with Noggin or dorsomorphin/LDN193189 plus SB431542, producing PAX6-positive neural progenitors that can be further matured into neurons. The readout is generated by morphology, neural progenitor markers, neuronal markers, subtype markers, and functional assays: PAX6/SOX1/NESTIN indicate neural progenitor induction, βIII-tubulin/TUJ1 and MAP2 indicate neuronal differentiation, cortical programs can be assessed by FOXG1, TBR1, CTIP2, SATB2, and synaptic maturation can be assessed by synaptic proteins, calcium activity, multielectrode arrays, or patch-clamp electrophysiology.

Apoptosis, also called programmed cell death, is generally characterized by distinct morphological characteristics.

SH-SY5Y neuronal differentiation culture uses sequential exposure to retinoic acid and neurotrophic factors to reduce proliferative neuroblastoma-like behavior and induce neuron-like morphology, including neurite extension, neuronal marker expression, and, in RA/BDNF protocols, greater synaptic-marker expression than undifferentiated culture. Retinoic acid is commonly used as the initiating differentiation cue, while BDNF in serum-reduced or serum-free medium supports later maturation and neurotrophic-factor-dependent neuron-like survival.

Cytotoxicity assays are usually based on the assessment of cell membrane damage, which can also be indirectly detected by measuring cell viability. Detection methods include MTT assay, CKK-8 assay, LDH assay and ATP assay, etc.

Human pluripotent stem cell neural induction can be achieved by blocking BMP and TGFβ/Activin/Nodal SMAD signaling, which suppresses non-neural differentiation and promotes early neuroectodermal identity; the expected readout is loss of pluripotency markers such as OCT4 and induction of neural markers such as PAX6, followed by neural progenitor and neuron marker acquisition during differentiation. This protocol uses dual-SMAD neural induction as the core induction method, followed by cortical neuron differentiation as a representative neuron differentiation model; published cortical protocols describe generation of cortical progenitors, temporally ordered cortical projection neurons, action-potential firing, synaptogenesis, and neural network formation over an approximately 80-day process.

SH-SY5Y neuronal-like differentiation uses defined culture conditions to shift proliferative human neuroblastoma cells toward a neuron-like state, mainly assessed by reduced proliferation, neurite extension, neuronal-marker expression, and, in some protocols, increased dependence on neurotrophic support. Retinoic acid (RA) is commonly used for the first differentiation phase, and sequential RA followed by brain-derived neurotrophic factor (BDNF) in serum-free medium is a well-characterized approach for generating neuron-like SH-SY5Y cultures with extensive neurite outgrowth. The primary readouts are morphology-based neurite outgrowth and marker-based confirmation using proteins such as βIII-tubulin, MAP2, GAP43, synaptophysin, NeuN, NSE, TH, or related neuronal/synaptic markers, depending on the study endpoint.

TEER measures electrical resistance across epithelial or endothelial monolayers cultured on permeable supports, and the readout reflects ionic conductance through the cell barrier, especially the paracellular pathway regulated by junctional integrity. TEER can be measured without destroying the monolayer and is commonly used before or during transport, permeability, barrier-disruption, and barrier-maturation experiments. TEER values are influenced by biological maturation and technical conditions; reported factors include temperature, medium formulation, passage number, electrode geometry, membrane properties, and junctional length during early monolayer maturation. Therefore, TEER should be interpreted with blank-insert subtraction, area normalization, repeated readings, and, when possible, orthogonal barrier readouts such as FITC-dextran flux or tight-junction staining.

Apoptosis is a regulated, generally non-lytic cell-death pathway that removes unwanted, damaged, infected, or abnormal cells through coordinated morphological changes, caspase activation, DNA fragmentation, and membrane remodeling. The intrinsic apoptosis pathway is controlled mainly by mitochondrial outer membrane permeabilization, BCL-2 family proteins, cytochrome c release, apoptosome formation, caspase-9 activation, and downstream executioner caspase-3/7 activation. The extrinsic apoptosis pathway is initiated by death receptors such as Fas, TNFR, and TRAIL receptors, which recruit adaptor proteins and activate caspase-8 before engaging executioner caspases or mitochondrial amplification through BID cleavage. Apoptosis is linked to many phenotypes, including cancer cell killing, tissue homeostasis, immune regulation, neurodegeneration, infection response, and treatment-induced cytotoxicity; unresolved questions include how apoptosis interacts with necroptosis, pyroptosis, ferroptos