Next generation of non-mammalian blood-brain barrier models to study parasitic infections of the central nervous system

Locusts: A Model to Investigate Human Disease and Sickness Behavior

Traditionally, vertebrate models have been utilized and are viewed as more pertinent; however, we propose the application of an invertebrate model such as locusts to study human disease and sickness behavior at an early phase of research. This model has numerous benefits, namely, expense, swiftness, procedural convenience, and ethical acceptance. For example, the injection of immunogen-induced anorexia behavior in rats and locusts in vivo are analogous. Moreover, the presence of a brain barrier in locusts reveals remarkable similarities in molecular methods utilized by E. coli K1 to traverse the central nervous system of rats and locusts, consequently providing a worthwhile model to investigate pathogenesis. The presence of cytokines in these insects and presence of a brain barrier (which is physiologically relevant to human blood-brain barrier) makes it a relevant model in determining disease mechanisms and invasion of the brain by central nervous system pathogens.

Model systems for studying the blood-brain barrier: Applications and challenges

The blood-brain barrier (BBB) poses a serious impediment to the delivery of effective therapies to the central nervous system (CNS). Over time, various model systems have been crafted and used to evaluate the complexities of the BBB, which includes an impermeable physical barrier and a series of energy-dependent efflux pumps. Models of the BBB have mainly sought to assess changes in endothelial cell permeability, the role of ATP-dependent efflux transporters in drug disposition, and alterations in communication between BBB cells and the microenvironment. In the context of disease, various animal models have been utilized to examine real time BBB drug permeability, CNS dynamic changes, and overall treatment response. In this review, we outline the use of these in vitro and in vivo blood-brain barrier model systems to study normal physiology and diseased states. These current models each have their own advantages and disadvantages for studying the response of biologic processes to physiological and pathological conditions. Additional models are needed to mimic more closely the dynamic quality of the BBB, with the goal focused on potential clinical applications.