title: Novel tracing paradigms--genetically engineered herpesviruses as tools for mapping functional circuits within the CNS: present status and future prospects.
abstract: The mammalian CNS is composed of an extremely complex meshwork of highly ordered interconnections among billions of neurons. To understand the diverse functions of this neuronal network we need to differentiate between functionally related and nonrelated elements. A powerful labeling method for defining intricate neural circuits is based on the utilization of neurotropic herpesviruses, including pseudorabies virus and herpes simplex virus type 1. The recent development of genetically engineered tracing viruses can open the way toward the conception of novel tract-tracing paradigms. These new-generation tracing viruses may facilitate the clarification of problems, which were inaccessible to earlier approaches. This article first presents a concise review of the general aspects of neuroanatomical tracing protocols. Subsequently, it discusses the molecular biology of alpha-herpesviruses, and the genetic manipulation and gene expression techniques that are utilized for the construction of virus-based tracers. Finally, it describes the current utilization of genetically modified herpesviruses for circuit analysis, and the future directions in their potential applications.
authors.affiliation: Laboratory of Neuromorphology, Department of Anatomy, Faculty of Medicine, Semmelweis University and Hungarian Academy of Sciences, Budapest, Hungary. boldog@sb4.szote.u-szeged.hu
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Boldogköi
authors.forename: Attila
authors.initials: A
authors.lastname: Sík
authors.forename: Adám
authors.initials: A
authors.lastname: Dénes
authors.forename: Anikó
authors.initials: A
authors.lastname: Reichart
authors.forename: József
authors.initials: J
authors.lastname: Toldi
authors.forename: Ida
authors.initials: I
authors.lastname: Gerendai
authors.forename: Krisztina J
authors.initials: KJ
authors.lastname: Kovács
authors.forename: Miklós
authors.initials: M
authors.lastname: Palkovits
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002490:Central Nervous System / Q000033:anatomy & histology / Q000502:physiology* / Q000821:virology; D005818:Genetic Engineering / Q000379:methods*; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D008957:Models, Genetic; D009434:Neural Pathways / Q000502:physiology* / Q000821:virology; D009473:Neuronal Plasticity / Q000502:physiology