Extracellular vesicles from the CNS play pivotal roles in neuroprotection and neurodegeneration: lessons from in vitro experiments.

Intercellular communication between diverse cell types is crucial for the maintenance of the central nervous system, and exosomes have been shown to play an important role in this process. Exosomes are small extracellular vesicles (EVs) that are released by all cell types and carry cargoes that can elicit downstream effects in recipient cells. Exosomal communication in the central nervous system has been implicated in many neurodegenerative diseases, ranging from Alzheimer's disease to major depressive disorder. Though there remain many unknowns in the field of EV biology, in vitro experiments can provide many insights into their potential roles in health and disease. In this review, we discuss the findings of many in vitro EV experiments, with a focus on the potential roles in regulating cell viability, inflammation, oxidative stress, and neurite integrity in the central nervous system.

Recipient Reaction and Composition of Autologous Sural Nerve Tissue Grafts into the Human Brain.

Parkinson's disease (PD) is a severe neurological disease for which there is no effective treatment or cure, and therefore it remains an unmet need in medicine. We present data from four participants who received autologous transplantation of small pieces of sural nerve tissue into either the basal forebrain containing the nucleus basalis of Meynert (NBM) or the midbrain substantia nigra (SN). The grafts did not exhibit significant cell death or severe host-tissue reaction up to 55 months post-grafting and contained peripheral cells. Dopaminergic neurites showed active growth in the graft area and into the graft in the SN graft, and cholinergic neurites were abundant near the graft in the NBM. These results provide a histological basis for changes in clinical features after autologous peripheral nerve tissue grafting into the NBM or SN in PD.