Track topics on Twitter Track topics that are important to you
Arsenic is a contaminant of food and drinking water. Epidemiological studies have reported correlations between arsenic exposure and neurodevelopmental abnormalities, such as reduced sensory functioning, while in vitro studies have shown that arsenic reduces neurogenesis and alters stem cell differentiation. The goal of this study was assess whether arsenic exposure during embryogenesis reduced olfactory stem cell function and/or numbers, and if so, whether those changes persist into adulthood. Killifish (Fundulus heteroclitus) embryos were exposed to 0, 10, 50 or 200 ppb arsenite (As) until hatching, and juvenile fish were raised in clean water. At 0, 2, 4, 8, 16, 28 and 40 weeks of age, odorant response tests were performed to assess specific olfactory sensory neuron (OSN) function. Olfactory epithelia were then collected for immunohistochemical analysis of stem cell (Sox2) and proliferating cell numbers (PCNA), as well as the number and expression of ciliated (calretinin) and microvillus OSNs (G) at 0, 4, 16 and 28 weeks. Odorant tests indicated that arsenic exposure during embryogenesis increased the start time of killifish responding to pheromones, and this altered start time persisted to 40 weeks post-exposure. Response to the odorant taurocholic acid (TCA) was also reduced through week 28, while responses to amino acids were not consistently altered. Immunohistochemistry was used to determine whether changes in odorant responses were correlated to altered cell numbers in the olfactory epithelium, using markers of proliferating cells, progenitor cells, and specific OSNs. Comparisons between response to pheromones and PCNA + cells indicated that, at week 0, both parameters in exposed fish were significantly reduced from the control group. At week 28, all exposure are still significantly different than control fish, but now with higher PCNA expression coupled with reduced pheromone responses. A similar trend was seen in the comparisons between Sox2-expressing progenitor cells and response to pheromones, although Sox2 expression in the 28 week-old fish only recovers back to the level of control fish rather than being significantly higher. Comparisons between calretinin expression (ciliated OSNs) and response to TCA demonstrated that both parameters were reduced in the 200 ppb arsenic-exposed fish in at weeks 4, 16, and 28. Correlations between TCA response and the number of PCNA + cells revealed that, at 28 weeks of age, all arsenic exposure groups had reductions in response to TCA, but higher PCNA expression, similar to that seen with the pheromones. Few changes in G (microvillus OSNs) were seen. Thus, it appears that embryonic-only exposure to arsenic has long-term reductions in proliferation and differentiation of olfactory sensory neurons, leading to persistent effects in their function.
This article was published in the following journal.
The parallel processing of chemical signals by the main olfactory system and the vomeronasal system has been known to control animal behavior. The physiological significance of peripheral parallel pat...
Sensory navigation results from coordinated transitions between distinct behavioral programs. During chemotaxis in the larva, the detection of positive odor gradients extends runs while negative grad...
Odorant molecules are detected through the combinatorial activation of ensembles of olfactory sensory neurons. By capitalizing on the numerical simplicity of the Drosophila larval brain, Si et al. (2...
The olfactory epithelium of fish includes three main types of olfactory sensory neurons (OSNs). Whereas ciliated (cOSNs) and microvillous olfactory sensory neurons (mOSNs) are common to all vertebrate...
Fish rely heavily on their sense of smell to maintain behaviors essential for survival, such as predator detection and avoidance, prey selection, social behavior, imprinting, and homing to natal strea...
While reducing arsenic (As) exposure in Bangladesh and the U.S. must continue to be a top priority, this has proven difficult. After decades of mitigation efforts, 42 million people in Ban...
Signal processing in the olfactory neuron could be influenced by inhibition of enzymes like phosphodiesterase. Pentoxifylline is a unspecific phosphodiesterase inhibitor. The hypothesis is...
Post-traumatic stress disorder (PTSD) is associated with altered processing of sensory stimuli. The clinical phenotype of PTSD has predominantly been described for the visual and auditory ...
During the past three decades, researchers have paid particular attention to the study of olfactory disorders in depression. Recent studies have shown that depression is characterized by a...
The purpose of this study is to determine whether folic acid, alone or together with creatine supplementation, can lower blood arsenic concentrations and improve the ability to detoxify ar...
That portion of the nasal mucosa containing the sensory nerve endings for SMELL, located at the dome of each NASAL CAVITY. The yellow-brownish olfactory epithelium consists of OLFACTORY RECEPTOR NEURONS; brush cells; STEM CELLS; and the associated olfactory glands.
Disorders associated with acute or chronic exposure to compounds containing ARSENIC (ARSENICALS) which may be fatal. Acute oral ingestion is associated with gastrointestinal symptoms and an encephalopathy which may manifest as SEIZURES, mental status changes, and COMA. Chronic exposure is associated with mucosal irritation, desquamating rash, myalgias, peripheral neuropathy, and white transverse (Mees) lines in the fingernails. (Adams et al., Principles of Neurology, 6th ed, p1212)
Set of nerve fibers conducting impulses from olfactory receptors to the cerebral cortex. It includes the OLFACTORY NERVE; OLFACTORY BULB; olfactory tract, olfactory tubercle, anterior perforated substance, and olfactory cortex. The term rhinencephalon is restricted to structures in the CNS receiving fibers from the olfactory bulb.
The 1st cranial nerve. The olfactory nerve conveys the sense of smell. It is formed by the axons of OLFACTORY RECEPTOR NEURONS which project from the olfactory epithelium (in the nasal epithelium) to the OLFACTORY BULB.
Ovoid body resting on the cribriform plate of the ethmoid bone where the olfactory nerve terminates. The olfactory bulb contains several types of nerve cells including the mitral cells, on whose dendrites the olfactory nerve synapses, forming the olfactory glomeruli. The accessory olfactory bulb, which receives the projection from the VOMERONASAL ORGAN via the vomeronasal nerve, is also included here.
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism ...
Track and monitor developments in stem cell research and commercial development. Follow the tabs above to read the latest global news, research, clinical trials on stem cells and follow companies active in the stem cell industry. BioPort...