Moreover, there are several limitations in the interpretation of sympathetic response to vasoactive drugs, among them nitroprusside inhibition of sympathetic neurotransmission, or unpredictable effects of cardiac loading conditions on low-pressure mechanoreceptor nerve firing. We have not investigated other reflexes known to increase sympathetic outflow. Metabolic and mechanical stimuli from the contracting muscles can lead to an increase in SNS activity by taking a route which bypasses the classical afferent baroreflex pathway and does not involve the solitary tract nuclei in the brainstem. This mechanism has been suggested in a case-report of post physical exercise TTC. However in our study, physical exercise has not been identified as a trigger factor leading to TTC. Moreover mechanoreflex analysis implies the use of a handgrip test, difficult to perform in our cohort of very elderly patients and poorly reproducible. Activation of peripheral chemoreceptors leads to sympathetic activation, but in the present study, factors known to increase peripheral chemoreceptor activity in CHF patients such as creatinine clearance, baseline oxygen saturation and hemoglobin levels were similar in both groups. We have ICI 182780 previously shown that chemoreflex activation can contribute to sympathetic baroreflex impairment. Hence it cannot be excluded that autonomic dysfunction in TTC could be mediated by peripheral chemoreflex activation. The effect of the treatment on SNS activity is also a possible limitation of our study. For ethical and clinical reasons treatment was not withdrawn. However the percentage of patients treated with b-blockers and renin-angiotensin-aldosterone-system blockers was not significantly different between the two groups. Ticks are obligate blood-feeding ectoparasites that serve as vectors of the causative agents of many important diseases affecting humans and animals, e.g., Lyme disease, Rocky Mountain spotted fever, tick-borne encephalitis, anaplasmosis, babesiosis and many others. The black-legged tick, Ixodes scapularis, is one of the most important vectors of infectious diseases to humans and animals throughout large areas of the United States and Canada. I. scapularis is the primary vector of the microbial agents of Lyme disease, human granulocytic anaplasmosis, human babesiosis, relapsing fever and an encephalitis-causing agent. Lyme disease is the most commonly reported vector-borne disease in the northern temperate zone regions of the northern hemisphere with 24,364 confirmed cases in the United States in 2011. Despite the many zoonotic diseases caused by tick-borne pathogens, control of ticks is still largely dependent on the use of chemical acaricides, with traditional acaricide targets being primarily neurologically-based. The central nervous system in ticks is composed of a single mass called the synganglion. Despite the fact that most acaricides target the nervous system, relatively little is known about tick neurobiology and how bloodfeeding and mating affect gene expression in the synganglion.