BrainPhys for Advanced Cellular and Synaptic Research

Studying neuronal function in vitro requires culture conditions that closely mimic the physiological environment of the brain. Traditional media often fail to support synaptic activity, making it challenging to study complex neural interactions.

BrainPhys was developed to address this limitation by optimizing neuronal survival while maintaining active synaptic transmission. This advancement has made it a valuable tool for researchers investigating neural circuits and cellular mechanisms.

Composition And Ion Regulation

BrainPhys replicates the brain’s extracellular environment, ensuring neurons maintain physiological properties in vitro. Traditional culture media often contain imbalanced ion concentrations, either excessive or deficient, which can disrupt synaptic function. BrainPhys carefully calibrates sodium (Na⁺), potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺), and chloride (Cl⁻) levels to reflect cerebrospinal fluid (CSF) and interstitial brain fluid, preventing artificial hyperexcitability or synaptic depression.

Calcium and magnesium regulation is particularly critical, as these ions directly influence neurotransmitter release and synaptic plasticity. BrainPhys maintains Ca²⁺ at levels that promote vesicular release without inducing excitotoxicity. Similarly, Mg²⁺ is adjusted to prevent aberrant NMDA receptor activation, which can cause neuronal stress and altered synaptic dynamics. This precise control ensures neurons exhibit firing patterns and synaptic responses comparable to those observed in vivo.

BrainPhys also employs a bicarbonate-based buffering system, stabilizing pH without interfering with neuronal function. Unlike conventional media that use HEPES, which can disrupt physiological CO₂/HCO₃⁻ homeostasis, BrainPhys preserves the brain’s natural acid-base regulation. This allows neurons to maintain intracellular pH and metabolic activity, benefiting long-term cultures where pH fluctuations can impact viability and synaptic integrity.

Types Of BrainPhys Formulations

BrainPhys is available in multiple formulations tailored to different experimental needs. Each maintains physiological ion balance and synaptic support while incorporating specific modifications for enhanced compatibility.

Original

The original BrainPhys formulation optimizes neuronal cultures for studies requiring active synaptic transmission. It replaces traditional media like Neurobasal and DMEM/F12, which often fail to sustain long-term synaptic activity. Its balanced mix of sodium, potassium, calcium, and magnesium closely mimics CSF, enabling neurons to maintain spontaneous and evoked synaptic activity over extended periods. This makes it well-suited for electrophysiology, live-cell imaging, and functional assays.

BrainPhys supports the maturation of human-induced pluripotent stem cell (hiPSC)-derived neurons, promoting physiologically relevant firing patterns and synaptic connectivity. This makes it particularly useful for disease modeling, drug screening, and neurodevelopmental research, where preserving native neuronal function is essential.

Without Phenol Red

BrainPhys is also available without phenol red, a pH indicator that can interfere with fluorescence-based imaging and optogenetics. Removing phenol red minimizes background fluorescence, improving signal clarity in calcium imaging, Förster resonance energy transfer (FRET), and genetically encoded voltage indicators (GEVIs).

Phenol red has weak estrogenic activity, which can affect studies involving hormone-sensitive pathways or neuroendocrine research. Eliminating this compound provides a more controlled biochemical environment while maintaining the same ionic balance and buffering system as the original formulation, ensuring neuronal excitability and synaptic function remain unaffected.

Plus Supplements

BrainPhys can be supplemented with additional factors to support specific experimental needs. B27 and N2 supplements provide essential nutrients, antioxidants, and growth factors that enhance neuronal survival and differentiation, particularly in long-term cultures.

Neurotrophic factors like brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) promote synaptic plasticity, dendritic growth, and neuronal survival. These additions are valuable for studies on neurodegeneration, synaptic remodeling, and hiPSC-derived neuron maturation. Researchers studying neurodevelopmental disorders or neuroprotective strategies often incorporate these factors to better replicate in vivo conditions.

With its flexible platform, BrainPhys allows researchers to fine-tune culture conditions to match their experimental models, making it a preferred choice for a wide range of neuroscience applications.

Synaptic Transmission Support

Neurons require finely tuned extracellular conditions for efficient synaptic communication, essential for cognitive function, memory formation, and neural circuitry development. Traditional media often fail to maintain the delicate balance of ions and neurotransmitter dynamics, leading to artificial hyperexcitability or synaptic silencing. BrainPhys preserves the physiological environment necessary for neurotransmitter release, receptor activation, and synaptic plasticity.

One of BrainPhys’s key advantages is its support for both excitatory and inhibitory synaptic transmission. Glutamatergic and GABAergic signaling pathways, which maintain excitatory-inhibitory balance, require precise calcium and magnesium levels for vesicular release and receptor function. In studies using hiPSC-derived neurons, BrainPhys cultures exhibited higher spontaneous excitatory postsynaptic current (sEPSC) frequencies and amplitudes compared to conventional media, reflecting more physiologically relevant synaptic connectivity. This makes it particularly useful for studying neurological disorders associated with synaptic dysfunction, such as epilepsy, schizophrenia, and autism spectrum disorders.

BrainPhys also enhances synaptic network maturation by promoting dendritic arborization and synapse formation. Neurons cultured in this medium display more extensive dendritic branching and a higher density of synaptic puncta, indicating improved synaptic integration. This is crucial for long-term cultures, where maintaining functional synapses is necessary for studying neurodevelopmental processes or pharmacological interventions. Additionally, BrainPhys’s optimized composition reduces synaptic fatigue, a common issue in prolonged neuronal recordings, ensuring more reliable electrophysiological and imaging-based assessments.

Compatibility With Imaging Techniques

Live-cell imaging is essential for studying neuronal function, requiring media that support cellular viability while minimizing optical interference. BrainPhys preserves neuronal morphology and synaptic activity while enhancing optical clarity. Its balanced ionic composition ensures neurons maintain physiological membrane potentials, preventing depolarization artifacts that can distort imaging-based activity measurements.

Optical transparency is crucial in fluorescence microscopy. BrainPhys eliminates unnecessary light-scattering components, unlike traditional media containing high concentrations of riboflavin and phenol red, which contribute to background fluorescence. The phenol red-free version reduces autofluorescence, improving signal-to-noise ratios in calcium imaging and Förster resonance energy transfer (FRET). This is particularly important for studies utilizing genetically encoded calcium indicators (GECIs) like GCaMP, where background fluorescence can obscure subtle intracellular calcium changes.

Relevance For Electrophysiology

Electrophysiological studies require culture conditions that preserve neurons’ natural firing properties while minimizing external influences that could distort signal recordings. BrainPhys ensures stable resting membrane potentials, appropriate action potential thresholds, and consistent synaptic responses over extended recording periods. This is particularly important for patch-clamp and multielectrode array (MEA) experiments, where deviations in ionic balance or buffering capacity can induce artificial hyperexcitability or synaptic dysfunction.

BrainPhys maintains both spontaneous and evoked synaptic activity, allowing researchers to study network-level dynamics with greater accuracy. Unlike traditional media that can lead to synaptic rundown, BrainPhys preserves excitatory and inhibitory neurotransmission over long durations, enabling extended recordings without significant signal degradation. This stability is essential for studying plasticity mechanisms such as long-term potentiation (LTP) and long-term depression (LTD), which require sustained neuronal activity for accurate measurement.

Its bicarbonate-based buffering system ensures pH stability within physiological ranges, preventing drifts that could interfere with ion channel function and neuronal excitability. These properties make BrainPhys a reliable choice for electrophysiological studies, supporting accurate and reproducible neuronal recordings.