The Center for Research and Advanced Studies of the National Polytechnic Institute is a Mexican non-governmental scientific research affiliated to the National Polytechnic Institute and founded by president Adolfo López Mateos on 17 April 1961, initially planned as a posgraduate department of the National Polytechnic Institute, which was later modified by President José López Portillo, on the 17 September 1982.The modification by President Portillo stipulates that it is a decentralized organ of public interest, with legal personality and own patrimony. Cinvestav receives an annual subsidy by the Federal Government to fund its operations. Wikipedia.
Heil M.,CINVESTAV |
Karban R.,University of California at Davis
Trends in Ecology and Evolution | Year: 2010
In spite of initial doubts about the reality of 'talking trees', plant resistance expression mediated by volatile compounds that come from neighboring plants is now well described. Airborne signals usually improve the resistance of the receiver, but without obvious benefits for the emitter, thus making the evolutionary explanation of this phenomenon problematic. Here, we discuss four possible non-exclusive explanations involving the role of volatiles: in direct defense, as within-plant signals, as traits that synergistically interact with other defenses, and as cues among kin. Unfortunately, there is a lack of knowledge on the fitness consequences of plant communication for both emitter and receiver. This information is crucial to understanding the ecology and evolution of plant communication via airborne cues. © 2009 Elsevier Ltd. All rights reserved.
Reviews in the Neurosciences | Year: 2013
Drugs acting through 5-hydroxytryptamine (serotonin or 5-HT) systems modulate memory and its alterations, although the mechanisms involved are poorly understood. 5-HT drugs may present promnesic and/or antiamnesic (or even being amnesic) effects. Key questions regarding 5-HT markers include whether receptors directly or indirectly participate and/or contribute to the physiological and pharmacological basis of memory and its pathogenesis; hence, the major aim of this article was to examine recent advances in emergent targets of the 5-HT systems for memory formation and memory alterations. Recent reviews and findings are summarized, mainly in the context of the growing notion of memory deficits in brain disorders (e.g., posttraumatic stress disorder, mild cognitive impairment, consumption of drugs, poststroke cognitive dysfunctions, schizophrenia, Parkinson disease, and infection-induced memory impairments). Mainly, mammalian and (some) human data were the focus. At least agonists and antagonists for 5-HT1A/1B, 5-HT2A/2B/2C, 5-HT3, 5-HT4, 5-HT6, and 5-HT7 receptors as well as serotonin uptake inhibitors seem to have a promnesic and/or antiamnesic effect in different conditions and 5-HT markers seem to be associated to neural changes. Available evidence offers clues about the possibilities, but the exact mechanisms remain unclear. For instance, 5-HT transporter expression seems to be a reliable neural marker related to memory mechanisms and its alterations. © 2013 by Walter de Gruyter Berlin Boston.
Chin-Chan M.,CINVESTAV |
Navarro-Yepes J.,CINVESTAV |
Frontiers in Cellular Neuroscience | Year: 2015
Neurodegenerative diseases including Alzheimer (AD) and Parkinson (PD) have attracted attention in last decades due to their high incidence worldwide. The etiology of these diseases is still unclear; however the role of the environment as a putative risk factor has gained importance. More worryingly is the evidence that pre- and post-natal exposures to environmental factors predispose to the onset of neurodegenerative diseases in later life. Neurotoxic metals such as lead, mercury, aluminum, cadmium and arsenic, as well as some pesticides and metal-based nanoparticles have been involved in AD due to their ability to increase beta-amyloid (Aβ) peptide and the phosphorylation of Tau protein (P-Tau), causing senile/amyloid plaques and neurofibrillary tangles (NFTs) characteristic of AD. The exposure to lead, manganese, solvents and some pesticides has been related to hallmarks of PD such as mitochondrial dysfunction, alterations in metal homeostasis and aggregation of proteins such as α-synuclein (α-syn), which is a key constituent of Lewy bodies (LB), a crucial factor in PD pathogenesis. Common mechanisms of environmental pollutants to increase Aβ, P-Tau, α-syn and neuronal death have been reported, including the oxidative stress mainly involved in the increase of Aβ and α-syn, and the reduced activity/protein levels of Aβ degrading enzyme (IDE)s such as neprilysin or insulin IDE. In addition, epigenetic mechanisms by maternal nutrient supplementation and exposure to heavy metals and pesticides have been proposed to lead phenotypic diversity and susceptibility to neurodegenerative diseases. This review discusses data from epidemiological and experimental studies about the role of environmental factors in the development of idiopathic AD and PD, and their mechanisms of action. © 2015 Chin-Chan, Navarro-Yepes and Quintanilla-Vega.
Reviews in the Neurosciences | Year: 2014
Agonists and antagonists of the 5-hydroxytryptamine (serotonin) receptor6 (5-HT6) or receptor7 (5-HT7) might improve memory and/or reverse amnesia, although the mechanisms involved are poorly understood. Hence, the current work summarizes recent reviews and findings involving these receptors. Evidence indicates that diverse 5-HT6receptor antagonists produce promnesic and/or antiamnesic effect in conditions, such as memory formation, age-related cognitive impairments and memory deficit in preclinical studies, as well as in diseases such as schizophrenia, Parkinson's, and Alzheimer's disease (AD). Memory, aging, and AD modify 5-HT6receptors and signaling cascades; likewise, the modulation of 5-HT6drugs on memory seems to be accompanied with neural changes. Moreover, 5-HT7receptors are localized in brain areas mediating memory, including the cortex, hippocampus (e.g., Zola-Morgan and Squire, 1993) and raphe nuclei; however, the role of these receptors on memory has yet to be fully explored. Hence, findings and reviews are summarized in this work. Evidence suggests that both 5-HT7receptor agonists and antagonists might have promnesic and anti-amnesic effects. These effects seem to be dependent on the basal level of performance, i.e., normal or impaired. Available evidence suggests that a potential utility of 5-HT6and 5-HT7receptor in mild-to-moderate AD patients and other memory dysfunctions as therapeutic targets.
Reviews in the Neurosciences | Year: 2014
A hyperactive hypothalamic-pituitary-adrenal (HPA) axis is a common feature of stress-related disorders, and the brain serotonin (5-HT) system plays a major role in HPA axis modulation. Glucocorticoids and stress profoundly affect the 5-HT system so it is possible that alterations of endocrine 5-HT mechanisms may underlie HPA axis overdrive in stress-related diseases. Available evidence suggests a role of 5-HT1A, 5-HT2A/2Cand 5-HT7receptors in HPA system activation, and pharmacological blockade of 5-HT7receptors produces a fast-acting antidepressant-like action and shortens the onset of antidepressant-like effects of various classes of antidepressants. The mechanisms involved in this effect have not been elucidated, but recent findings suggest a role of 5-HT7receptors in the development of HPA axis overdrive as a result of chronic stress. Remarkably, clinical findings have shown an association between corticosteroid-producing adenomas and expression of ectopic 5-HT7receptors in corticosteroid-producing adrenocortical cells. These observations might therefore reveal an endocrine mechanism for the antidepressant-like action of 5-HT7receptor blockers, possibly through normalization of HPA axis function. If such a preliminary hypothesis is confirmed, the potential therapeutic usefulness of 5-HT7receptor antagonists could extend beyond depression to include other diseases, the pathophysiology of which has been associated with chronic stress and HPA axis dysregulation.
Reviews in the Neurosciences | Year: 2017
The evidence for neural markers and memory is continuously being revised, and as evidence continues to accumulate, herein, we frame earlier and new evidence. Hence, in this work, the aim is to provide an appropriate conceptual framework of serotonergic markers associated with neural activity and memory. Serotonin (5-hydroxytryptamine [5-HT]) has multiple pharmacological tools, well-characterized downstream signaling in mammals' species, and established 5-HT neural markers showing new insights about memory functions and dysfunctions, including receptors (5-HT1A/1B/1D, 5-HT2A/2B/2C, and 5-HT3-7), transporter (serotonin transporter [SERT]) and volume transmission present in brain areas involved in memory. Bidirectional influence occurs between 5-HT markers and memory/amnesia. A growing number of researchers report that memory, amnesia, or forgetting modifies neural markers. Diverse approaches support the translatability of using neural markers and cerebral functions/dysfunctions, including memory formation and amnesia. At least, 5-HT1A, 5-HT4, 5-HT6, and 5-HT7 receptors and SERT seem to be useful neural markers and therapeutic targets. Hence, several mechanisms cooperate to achieve synaptic plasticity or memory, including changes in the expression of neurotransmitter receptors and transporters. © 2017 Walter de Gruyter GmbH, Berlin/Boston 2017.
Journal of Physiology | Year: 2014
Plants respond to mechanical wounding, herbivore feeding or infection by pathogens with the release of volatiles. Small C6 molecules termed green-leaf volatiles form a general element in most of these blends; however, the overall composition is usually sufficiently specific that other organisms are able to determine the nature of the attacker. Receivers of herbivore-induced volatile organic compounds (HI-VOCs) comprise distant parts of the same plant ('within-plant signalling'), neighbouring plants ('plant-plant signalling'), herbivores, and multiple carnivores that respond to the 'plant's cry for help', such as parasitoids and hyperparasitoids, entomopathogenic nematodes, and predatory mites, beetles, bugs and birds. In spite of intensive research efforts, many central questions still remain. How do plants perceive volatiles? What is the relative impact of each of the interactions with different receivers of HI-VOCs on the fitness of the emitting plant and that of the interacting organisms? How long can these compounds remain stable in the atmosphere? Why are VOC-mediated effects on herbivores and beneficial organisms not used as a common tool in sustainable agriculture? Here, I briefly summarize the ecological effects of HI-VOC perception and discuss the most pertinent questions raised by participants at the 32nd New Phytologist Symposium in Buenos Aires. © 2014 New Phytologist Trust.
Journal of Ecology | Year: 2013
Multiple plant species are engaged in defensive mutualisms with members of the third trophic level. However, mutualisms are prone to exploitation by low-quality symbionts that do not provide the adequate service to their host. Can mutualisms proceed only when hosts identify their symbionts in advance or continuously monitor their activity, or are there other mechanisms to avoid the invasion of mutualisms by exploiters? High-reward species amongst Mesoamerican Acacia myrmecophytes are dominantly colonized by defending mutualistic ants, whereas about 50% of the low-reward hosts are inhabited by non-defending exploiters. I followed the development of recently founded ant colonies on a high-reward and a low-reward Acacia host species over 7 months, to investigate whether reward production correlates with a preferred maintenance of defending ants on the respective hosts. Ant diversity decreased sooner on high-reward than on low-reward hosts, and mutualistic ants were more likely to finally dominate the high-reward hosts. I observed an increased frequency of mutualists replacing parasites at high initial rates of reward production. Apparently, higher nectar provisioning by the host plants shifted the competitive balance between mutualistic and parasitic ants. Independently of the causal reason for the different secretion rates, producing more nectar thereby favours the maintenance of defending mutualists on high-reward hosts. Synthesis. The aggressiveness that enables ants to outcompete other ants also underlies their defensive effect against herbivores. I conclude that hosts can preferably associate with high-quality mutualists without measuring their effectiveness. Mutualisms remain stable when partner screening is based on traits that are relevant for the mutualistic interaction, with no need for the host to have information on the quality or identity of the symbiont. © 2013 The Authors. Journal of Ecology © 2013 British Ecological Society.
Reports on Progress in Physics | Year: 2013
Energetic collisions of subatomic particles with fixed or moving targets have been very valuable to penetrate into the mysteries of nature. But the mysteries are quite intriguing when projectiles and targets are macroscopically immense. We know that countless debris wandering in space impacted (and still do) large asteroids, moons and planets; and that millions of craters on their surfaces are traces of such collisions. By classifying and studying the morphology of such craters, geologists and astrophysicists obtain important clues to understand the origin and evolution of the Solar System. This review surveys knowledge about crater phenomena in the planetary science context, avoiding detailed descriptions already found in excellent papers on the subject. Then, it examines the most important results reported in the literature related to impact and penetration phenomena in granular targets obtained by doing simple experiments. The main goal is to discern whether both schools, one that takes into account the right ingredients (planetary bodies and very high energies) but cannot physically reproduce the collisions, and the other that easily carries out the collisions but uses laboratory ingredients (small projectiles and low energies), can arrive at a synergistic intersection point. © 2013 IOP Publishing Ltd.
Trends in Plant Science | Year: 2011
Nectar contains water, sugars and amino acids to attract pollinators and defenders and is protected from nectar robbers and microorganisms by secondary compounds and antimicrobial proteins. Floral and extrafloral nectar secretion can be induced by jasmonic acid, it is often adjusted to consumer identity and consumption rate and depends on invertase activity. Invertases are likely to play at least three roles: the uploading of sucrose from the phloem, carbohydrate mobilization during active secretion and the postsecretory adjustment of the sucrose:hexose ratio of nectar. However, it remains to be studied how plants produce and secrete non-carbohydrate components. More research is needed to understand how plants produce nectar, the most important mediator of their interactions with mutualistic animals. © 2011 Elsevier Ltd.