Neuropeptides are small signaling molecules expressed in the tick central nervous system, i.e., the synganglion. The neuronal-like Ixodes scapularis embryonic cell line, ISE6, is an effective tool frequently used for examining tick–pathogen interactions. We detected 37 neuropeptide transcripts in the I. scapularis ISE6 cell line using in silico methods, and six of these neuropeptide genes were used for experimental validation. Among these six neuropeptide genes, the tachykinin-related peptide (TRP) of ISE6 cells varied in transcript expression depending on the infection strain of the tick-borne pathogen, Anaplasma phagocytophilum. The immunocytochemistry of TRP revealed cytoplasmic expression in a prominent ISE6 cell subpopulation. The presence of TRP was also confirmed in A. phagocytophilum-infected ISE6 cells. The in situ hybridization and immunohistochemistry of TRP of I. scapularis synganglion revealed expression in distinct neuronal cells. In addition, TRP immunoreaction was detected in axons exiting the synganglion via peripheral nerves as well as in hemal nerve-associated lateral segmental organs. The characterization of a complete Ixodes neuropeptidome in ISE6 cells may serve as an effective in vitro tool to study how tick-borne pathogens interact with synganglion components that are vital to tick physiology. Therefore, our current study is a potential stepping stone for in vivo experiments to further examine the neuronal basis of tick–pathogen interactions.

Heavily urbanized areas can hinder dispersal and gene flow between amphibian populations. Given the growth potential of urbanization, it is important to examine how this specific environment shapes their genetic patterns at the local scale. The ability of the European green toad to successfully colonize large human settlements has been convincingly confirmed in the recent past, but little is known about its population genetics under these new conditions. In this study, we examined the effects of the environment on genetic variation, population structure, and the level of gene flow in populations of this amphibian in the city of Košice and the adjacent rural area (eastern Slovakia) using a set of neutral genetic markers. We found that urban populations had lower genetic variability than populations in adjacent rural areas; however, the degree of inbreeding was relatively low in all samples. Genetic differentiation was higher, and gene flow was more restricted in urban area, although geographic distances between sites were significantly less than in rural area (2–4 km versus 6–13 km). Our analyses suggested genetic isolation of urban populations at sites with less suitable habitat for green toads. In contrast, admixture of the population inhabiting the large city park, established on a former floodplain, with all rural populations was likely the result of an intense historical gene flow. The densely developed environment of the other urban sites likely presents a strong barrier to gene flow. The lack of suitable wetland habitat prior to development suggests that these sites were only recently colonized by a limited number of founders. Thus, we found differential effects of the city on the population structure of the green toad. Understanding current local genetic variation and structure is important for future conservation plans in urban environments.

Induction of ischemic tolerance (IT), the ability of an organism to survive an otherwise lethal ischemia, is the most effective known approach to preventing postischemic damage. IT can be induced by exposing animals to a broad range of stimuli. In this study we tried to induce IT of brain neurons using ionizing radiation (IR). A preconditioning (pre-C) dose of 10, 20, 30 or 50 Gy of gamma rays was used 2 days before an 8 min ischemia in adult male rats. Ischemia alone caused the degeneration of almost one half of neurons in CA1 region of hippocampus. However, a significant decrease of the number of degenerating neurons was observed after higher doses of radiation (30 and 50 Gy). Moreover, ischemia significantly impaired the spatial memory of rats as tested in Morris's water maze. In rats with a 50 Gy pre-C dose, the latency times were reduced to values close to the control level. Our study is the first to reveal that IR applied in sufficient doses can induce IT and thus allow pyramidal CA1 neurons to survive ischemia. In addition, we show that the beneficial effect of IR pre-C is proportional to the radiation dose.