Table 1. Properties of Culture Media (C Bardy et al. Proc Natl Acad Sci USA, 2015)

Check-mark denotes physiological conditions and supported activities according to C Bardy et al. Proc Natl Acad Sci USA, 2015.

Figure 1. Protocol for Plating and Culturing Primary Neurons with the SM1 Culture System

Primary rodent tissue dissociated in papain was plated in NeuroCult™ Neuronal Plating Medium, supplemented with NeuroCult™ SM1 Neuronal Supplement, L-Glutamine, and L-Glutamic Acid. On day 5, primary neurons were transitioned to BrainPhys™ Neuronal Medium, supplemented with NeuroCult™ SM1 Neuronal Supplement, by performing half-medium changes every 3 - 4 days.

Figure 2. Protocol for Culturing hPSCs with the SM1 Culture System

hPSCs were maintained in mTeSR™1 medium and then differentiated using the STEMdiff™ SMADi Neural Induction Kit. Following plating on PLO/laminin, half-medium changes were performed to transition to BrainPhys™ Neuronal Medium for maturation and long-term culture.

Figure 3. The SM1 Culture System Supports Long-Term Culture of Rodent Neurons

Primary E18 rat cortical neurons were cultured in the SM1 Culture System. A large number of viable neurons are visible after (A) 21 and (B) 35 days, as demonstrated by their bright neuronal cell bodies, and extensive neurite outgrowth and branching. Neurons are evenly distributed over the culture surface with minimal cell clumping.

Figure 4. Pre- and Post-Synaptic Markers are Expressed in Rodent Neurons Cultured in the SM1 Culture System

Primary E18 rat cortical neurons were cultured in the SM1 Culture System. At 21 DIV, neurons are phenotypically mature, as indicated by the presence of an extensive dendritic arbor, and appropriate expression and localization of pre-synaptic synapsin (A,C; green) and post-synaptic PSD-95 (A,B; red) markers. Synapsin is concentrated in discrete puncta distributed along the somata and dendritic processes, as defined by the dendritic marker MAP2 (A,D; blue).

Figure 5. The SM1 Culture System Supports Increased Cell Survival

(A) Primary E18 rat cortical neurons were cultured in the SM1 Culture System or a Competitor Culture System for 21 days. Neurons cultured in the SM1 Culture System have a significantly higher number of viable cells compared to the competitor culture system (n = 4; mean ± 95% CI; *p < 0.05). (B) Primary E18 rat cortical neurons were cultured in Neurobasal® supplemented with NeuroCult™ SM1 Neuronal Supplement (SM1) or competitor B27-like supplements (Competitor 1,2,3) for 21 days. Cultures supplemented with NeuroCult™ SM1 Neuronal Supplement have an equal number of neurons compared to competitor-supplemented cultures. Bars represent standard error of mean.

Figure 6. BrainPhys™ Supports Improved Neuronal Activity and More Consistent Network Bursting in Long-Term Culture

Raster plots from MEA recordings show the firing patterns of primary E18 rat cortical neurons across 8 electrodes at Weeks 2, 4, 6 and 8. Neurons were either cultured with a Commercial Medium with Supplements, Commercial Medium Plus with Supplements, BrainPhys™ and SM1, or BrainPhys™ and SM1 with 15 mM glucose. Detected spikes (black lines), single channel bursts (blue lines; a collection of at least 5 spikes, each separated by an ISI of no more than 100 ms), and network bursts (magenta boxes; a collection of at least 50 spikes from a minimum of 35% of participating electrodes across each well, each separated by an ISI of no more than 100 ms) were recorded for each medium. (A-D) Neurons cultured with Commercial Medium exhibited network bursting in Week 2 but no spiking activity was detected in subsequent timepoints. (E-H) In Commercial Medium Plus-cultured neurons, a high number of spikes and regular network bursting were detected at Week 2. A decreased number of spikes and inconsistent network bursting were observed in later time points, corresponding to the drop in MFR seen in Figure 4. (I-L) Without glucose, individual spiking was observed at Weeks 2 and 4 with BrainPhys™ and SM1 but network bursting was not detected until Weeks 6 and 8. (M-T) In contrast, neurons cultured with BrainPhys™ and SM1 with 15 mM glucose demonstrated strong spiking activity and consistent network bursting at all timepoints. MEA = microelectrode array; ISI = inter-spike interval; MFR = mean firing rate

Figure 7. Glucose Supplementation in BrainPhys™ Maintains Neuronal Activity Over 8 Weeks in Culture

Primary E18 rat cortical neurons were cultured with BrainPhys™ and SM1 or other commercially available culture systems for 8 weeks. Neuronal activity can be detected at Day 9 with BrainPhys™, whereas activity is not detected until Day 14 in cultures maintained in either of the Commercial Media with Commercial Supplements. For Commercial Medium and Supplement-cultured neurons, mean firing rate remains low throughout culture. In contrast, a “peak-drop” activity pattern is observed in the Commercial Medium Plus condition, where mean firing rate increases rapidly within 2 days, followed by a drop in activity in the next 2 - 4 days. BrainPhys™and SM1 Kit with 15 mM glucose maintains the highest level of activity throughout the 8-week culture period.

Figure 8. hPSC-Derived Neurons Generated in BrainPhys™ Neuronal Medium Express Markers of Neuronal Maturity After 14 and 44 Days of Differentiation

NPCs were generated from H9 cells using STEMdiff™ Neural Induction Medium in an embryoid body-based protocol. Next, NPCs were cultured in (A,C) BrainPhys™ Neuronal Medium, supplemented with 2% NeuroCult™ SM1 Supplement, 1% N2 Supplement-A, 20 ng/mL GDNF, 20 ng/mL BDNF, 1 mM db-cAMP and 200 nM ascorbic acid to initiate neuronal differentiation, or (B,D) DMEM/F12 under the same supplementation conditions. After 14 and 44 days of differentiation and maturation, neurons express the synaptic marker Synapsin 1 (green) and the mature neuronal marker MAP2 (red). In this example, neurons matured in BrainPhys™ Neuronal Medium show increased Synapsin 1 staining. Scale bar= 100 µm

Figure 9. hPSC-Derived Neurons Generated in BrainPhys™ Neuronal Medium and NeuroCult™ SM1 and N2 Supplements are Healthy and Morphologically Normal

NPCs were generated from H9 cells using STEMdiff™ Neural Induction Medium in an embryoid body-based protocol. Next, NPCs were cultured for 44 DIV in (A) BrainPhys™ Neuronal Medium, supplemented with 2% NeuroCult™ SM1 Supplement, 1% N2 Supplement-A, 20 ng/mL GDNF, 20 ng/mL BDNF, 1 mM db-cAMP and 200 nM ascorbic acid to initiate neuronal differentiation, or (B) DMEM/F12 under the same supplementation conditions. Neuronal cultures differentiated from NPCs in BrainPhys™ Neuronal Medium display extensive neurite outgrowth and reduced cellular debris compared to cultures differentiated in DMEM/F12. Scale bar= 100 µm.

Figure 10. hPSC-Derived Neurons Matured in BrainPhys™ Neuronal Medium Show Improved Excitatory and Inhibitory Synaptic Activity

NPCs were generated from H9 cells using STEMdiff™ Neural Induction Medium in an embryoid body-based protocol. Next, NPCs were cultured for 44 DIV in (A,C) BrainPhys™ Neuronal Medium, supplemented with 2% NeuroCult™ SM1 Supplement, 1% N2 Supplement-A, 20 ng/mL GDNF, 20 ng/mL BDNF, 1 mM db-cAMP and 200 nM ascorbic acid to initiate neuronal differentiation, or (B,D) in DMEM/F12 under the same supplementation conditions. (A,C) Neurons matured in BrainPhys™ Neuronal Medium showed spontaneous excitatory (AMPA-mediated; A) and inhibitory (GABA-mediated; C) synaptic events. The frequency and amplitude of spontaneous synaptic events is consistently greater in neuronal cultures matured in BrainPhys™ Neuronal Medium, compared to neurons plated and matured in DMEM/F12 (B,D). Traces are representative.