Single cell sorting and isolation are fundamental techniques for analyzing cells. The downstream applications are almost endless and include diverse research fields such as cell engineering, cell line development, synthetic biology, rare cell isolation, monoclonal antibody development, and single cell genomics. Traditionally, scientists use methods such as fluorescence activated cell sorting (FACS) or limiting dilution assays to sort and isolate single cells for further investigation. Although these approaches are widely used and effective, they involve multiple steps, are time consuming, and yield a limited number of viable cells.

     

For example, the high pressure required to sort cells using FACS instruments causes stress to cells, altering key molecular pathways and diminishing their viability.^1,2 Moreover, this approach has multiple manual steps that increase the risk of cell contamination and device challenges such as blockages. In contrast, limiting dilution assays offer scientists a gentler approach to single cell sorting and isolation, but the process is long, labor intensive, and less efficient. As a result, researchers seek new approaches to streamline single cell dispensing workflows and improve the reliability and reproducibility of scientific data.

Innovative technologies pave the way for cell sorting solutions that recognize the limitations of traditional techniques. For example, the Namocell^TM Pala Single Cell Dispenser combines cutting-edge microfluidics, flow cytometry, and liquid dispensing technologies for automated, high-throughput single cell sorting and isolation. This benchtop single cell dispenser is faster, easier, and gentler than conventional cell sorting techniques, allowing scientists to preserve cell viability, increase productivity, and decrease contamination and clogging. New technologies such as this are designed to be affordable, maintenance-free, FDA-compliant, and intuitive, allowing researchers to reallocate valuable resources and streamline cell analysis workflows.

Read more about automated single cell dispensing here.

If you’re expecting to add any miniatures to your family this season, hormones may help you prepare for them by rewiring your brain. Pregnancy hormones cause many changes in the body to prepare for offspring, and in rodents, this includes promoting parenting behaviors.^1,2 However, the changes to neurons and their activity that drive these behaviors are poorly understood.^3,4

Johannes Kohl, a neuroscientist at the Francis Crick Institute and coauthor of a recent study, and his team explored the influence of these hormones on neurons that control parental behavioral in mice.⁵ Understanding these changes could help researchers find interventions for postpartum depression or anxiety.

“The brain can prepare itself for specific future behavioral challenges,” Kohl said. “The way it does this is by just listening to the body.”

The team assessed parenting behaviors in female mice, such as retrieving pups and crouching over them, before, during, and after pregnancy by placing two pups into their cages. They also investigated the influence of estradiol (E2) and progesterone (P4) on these activities and on activity in galanin-expressing (Gal⁺) neurons in an area of the hypothalamus that controls many of these activities.

Even mice that only saw pups before and at the end of pregnancy exhibited more parenting behaviors as pregnancy progressed. However, the loss of either the E2 or P4 receptor impaired these behaviors. Using patch-clamp electrophysiology, the team showed that E2 decreased the baseline of Gal⁺ neurons but maintained their excitability after stimulation, while P4 increased the number of inputs that these neurons received. 

“This is really getting into the details of what different types of hormones are doing in very specific sets of neurons,” said Frances Champagne, a neuroscientist at the University of Texas at Austin who was not involved in the study. “It's really doing a nice job at bringing in some of the newer tools that we have now that weren't available back in the 1980s to really dissect out that plasticity and how it's represented with a particular focus on behavior.”

Brain infections caused by larvae of the tapeworm Taenia solium are common in many developing countries.¹ Once nestled in the brain, the parasite causes neurocysticercosis, an infection characterized by recurrent seizures. Scientists knew that the host’s inflammatory response to the larvae contributed to seizures in neurocysticercosis, but it was unclear whether the larvae directly altered neurons’ electrical activity. ^2,3

Now, researchers from the University of Cape Town report that tapeworm larvae directly affect neuronal firing by releasing excitatory amino acids, mainly glutamate, in their surroundings.⁴ Their findings, published in eLife, pave the way for developing potential new treatment options for seizures in neurocysticercosis. 

For the study, the researchers applied extracts of the larvae or their secretions to brain slices while recording the cells’ electrical activity using the patch clamp technique. Since T. solium larvae are difficult to find, Anja de Lange, a postdoctoral researcher at the University of Cape Town and coauthor of the study, and her colleagues used Taenia crassiceps, a tapeworm that infects rodents and is genetically similar to T. solium, for most of the experiments.

In normal conditions, exposure to parasite preparations caused neurons to fire, but when the team blocked neuronal glutamate receptors, they found no signal. Elevated glutamate levels in the parasite preparations further confirmed glutamate’s involvement.

Finally, to confirm that T. solium exposure showed similar results, the team hunted for T. solium larvae in an endemic region of South Africa and harvested a few from local infected pigs. Puffing T. solium preparations onto human brain slices induced neuronal firing, an effect also mediated by glutamate.  

Accumulating clinical evidence suggests that neurocysticercosis causes seizures in people with epilepsy who live in areas where T. solium is endemic, explained Jorge Burneo, a neurologist at Western University who was not involved in the research. “But we never had basic science evidence that that's the case.” 

Moving forward, the team plans to zoom in on T. solium by examining the effects of the parasite at different life stages on human brain slices and the interplay between the parasite and the inflammatory changes it induces in the brain. “We are quite passionate about this disease being studied more,” said de Lange.