The Optokinetic Response of Fishes to Different Levels of Turbidity

Many fish need light to school, reproduce, and forage. Without enough light penetrating into an aquatic system fish may not be able to accomplish these tasks, thus compromising their ability to persist. Turbidity, or suspended particles in the water, is a serious global problem due to increased run-off from urban and agricultural activities. High turbidity has the potential to reduce light to a point where fish are unable to detect the visual environment. The first objective to this project was to develop an optomotor response apparatus for testing the visual abilities of fish under increasing turbidity. Due to the optokinetic response, fish will swim with a rotating black and white grating until the turbidity reaches a peak where they can no longer sense the white striations, at which point the fish can no longer see the gradient and stops swimming (i.e. detection threshold). Under the parameters of 8 rotations per minute, striations 35 mm wide, and broad-spectrum lighting 15 individual fish showed responses to the rotating gradients. For the second objective, I used the optomotor apparatus to test the detection threshold under increasing turbidity for Pseudocrenilbrus multicolor victoria, a widespread East African cichlid fish that experiences extremes of human-induced turbidity. All fish that exhibited the optokinetic response (n = 15) were tested for a turbidity threshold. Males showed a significantly higher turbidity threshold (mean ± s.e. = 61.94 ± 3.03) level compared to females (mean ± s.e. = 52.64 ± 2.92). This research is beneficial because it can be applied to many different fish species experiencing increases in turbidity above natural levels and may contribute to our understanding of the mechanisms of population declines associated with increased turbidity.No embargoAcademic Major: Forestry, Fisheries, and Wildlif

Anticoagulation: a practical guide for strabismus surgeons.

An increasing number of surgical strabismus patients are taking oral anticoagulant and antiplatelet agents, with more diverse mechanisms of action than those used in the past. The decision as to whether to continue these drugs throughout the perioperative period is difficult and must be based on the balance between hemorrhagic and thrombotic risk. To help guide strabismus surgeons with clinical management in these cases, we review potential hemorrhagic complications of strabismus surgery and examine the use of anticoagulant and antiplatelet drugs during the perioperative period. Surgical strategies that might help minimize intraoperative hemorrhage in patients on anticoagulant therapy are also discussed

Ramping single unit activity in the medial prefrontal cortex and ventral striatum reflects the onset of waiting but not imminent impulsive actions.

The medial prefrontal cortex (mPFC) and ventral striatum (VS), including the nucleus accumbens, are key forebrain regions involved in regulating behaviour for future rewards. Dysfunction of these regions can result in impulsivity, characterized by actions that are mistimed and executed without due consideration of their consequences. Here we recorded the activity of single neurons in the mPFC and VS of 16 rats during performance on a five-choice serial reaction time task of sustained visual attention and impulsivity. Impulsive responses were assessed by the number of premature responses made before target stimuli were presented. We found that the majority of cells signalled trial outcome after an action was made (both rewarded and unrewarded). Positive and negative ramping activity was a feature of population activity in the mPFC and VS (49.5 and 50.4% of cells, respectively). This delay-related activity increased at the same rate and reached the same maximum (or minimum) for trials terminated by either correct or premature responses. However, on premature trials, the ramping activity started earlier and coincided with shorter latencies to begin waiting. For all trial types the pattern of ramping activity was unchanged when the pre-stimulus delay period was made variable. Thus, premature responses may result from a failure in the timing of the initiation of a waiting process, combined with a reduced reliance on external sensory cues, rather than a primary failure in delay activity. Our findings further show that the neural locus of this aberrant timing signal may emanate from structures outside the mPFC and VS.This research was funded in part by a Medical Research Council grant to J.W.D. (G0701500) and by a joint award from the Medical Research Council (G1000183) and Wellcome Trust (093875/Z/10/Z) in support of the Behavioural and Clinical Neuroscience Institute at Cambridge University. N.A.D. was funded by the University of Cambridge School of Clinical Medicine MB/PhD Program. The authors would like to thank Alan Lyon and David Theobald for assistance with histology, Tim Harris and the Applied Physics and Instrumentation Group at HHMI Janelia Farm for providing electrodes, Ken Harris and the Klustateam at UCL for providing software for spike detection and sorting, and Tahl Holtzman for technical assistance with training in surgical procedures.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/ejn.1289

Dissociable effects of mGluR5 allosteric modulation on distinct forms of impulsivity in rats: interaction with NMDA receptor antagonism

Rationale: Impaired N-methyl-D-aspartate (NMDA) receptor signalling underlies several psychiatric disorders that express high levels of impulsivity. Although synergistic interactions exist between NMDA receptors and metabotropic glutamate receptor 5 (mGluR5), the significance of this interaction for impulsivity is unknown. Objective This study aims to investigate the effects of negative and positive allosteric mGluR5 modulation (NAM/PAM) on trait impulsivity and impulsivity evoked by NMDA receptor antagonism in rats. Methods: Motor and choice impulsivity were assessed using the five-choice serial reaction time task (5-CSRTT) and delayeddiscounting task (DDT), respectively. The effects of RO4917523 and 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) (NAMs) and ADX47273 (PAM) were investigated in non-impulsive rats and in trait high- and low-impulsive rats. The effects of these compounds on impulsivity induced by NMDA receptor antagonism (MK801) in the 5-CSRTT were also investigated. Results: RO4917523 (0.1–1 mg/kg) decreased premature responding and increased omissions but had no effect on locomotor activity up to 0.1 mg/kg. MTEP significantly increased omissions, decreased accuracy and slowed responding but had no effect on premature responding. ADX47273 decreased premature responding at doses that had no effect on locomotor activity. MK801 increased premature responding and impaired attentional accuracy; these deficits were dose dependently rescued by ADX47273 pre-treatment. Allosteric modulation of mGluR5 had no significant effect on choice impulsivity, nor did it modulate general task performance. Conclusions: These findings demonstrate that mGluR5 allosteric modulation selectively dissociates motor and choice impulsivity. We further show that mGluR5 PAMs may have therapeutic utility in selectively targeting specific aspects of impulsivity and executive dysfunction.This research was supported by a Medical Research Council (MRC) grant to JWD (G0701500) and a grant from Boehringer Ingelheim Pharma GmbH & Co. KG. This work was carried out in the Behavioural and Clinical Neuroscience Institute (BCNI) at Cambridge University with joint support from the MRC (G1000183) and Wellcome Trust (093875/Z/10/Z) and at Boehringer Ingelheim Pharma GmbH & Co. KG, Germany. We thank David Theobald, Johannes Freudenreich, Peter Schorn, Alfie Wearn and Benjamin Jaehnke for technical support and Gert Kramer, Dr. Holger Rosenbrock and Dr. Cornelia Dorner-Ciossek for helpful scientific discussions. The authors declare that the experiments performed in this manuscript followed the principles of laboratory animal care and are in compliance with the current laws of the UK and Germany.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00213-015-3984-

Dissociable effects of mGluR5 allosteric modulation on distinct forms of impulsivity in rats: interaction with NMDA receptor antagonism.

RATIONALE: Impaired N-methyl-D-aspartate (NMDA) receptor signalling underlies several psychiatric disorders that express high levels of impulsivity. Although synergistic interactions exist between NMDA receptors and metabotropic glutamate receptor 5 (mGluR5), the significance of this interaction for impulsivity is unknown. OBJECTIVE: This study aims to investigate the effects of negative and positive allosteric mGluR5 modulation (NAM/PAM) on trait impulsivity and impulsivity evoked by NMDA receptor antagonism in rats. METHODS: Motor and choice impulsivity were assessed using the five-choice serial reaction time task (5-CSRTT) and delayed-discounting task (DDT), respectively. The effects of RO4917523 and 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) (NAMs) and ADX47273 (PAM) were investigated in non-impulsive rats and in trait high- and low-impulsive rats. The effects of these compounds on impulsivity induced by NMDA receptor antagonism (MK801) in the 5-CSRTT were also investigated. RESULTS: RO4917523 (0.1-1 mg/kg) decreased premature responding and increased omissions but had no effect on locomotor activity up to 0.1 mg/kg. MTEP significantly increased omissions, decreased accuracy and slowed responding but had no effect on premature responding. ADX47273 decreased premature responding at doses that had no effect on locomotor activity. MK801 increased premature responding and impaired attentional accuracy; these deficits were dose dependently rescued by ADX47273 pre-treatment. Allosteric modulation of mGluR5 had no significant effect on choice impulsivity, nor did it modulate general task performance. CONCLUSIONS: These findings demonstrate that mGluR5 allosteric modulation selectively dissociates motor and choice impulsivity. We further show that mGluR5 PAMs may have therapeutic utility in selectively targeting specific aspects of impulsivity and executive dysfunction.This research was supported by a Medical Research Council (MRC) grant to JWD (G0701500) and a grant from Boehringer Ingelheim Pharma GmbH & Co. KG. This work was carried out in the Behavioural and Clinical Neuroscience Institute (BCNI) at Cambridge University with joint support from the MRC (G1000183) and Wellcome Trust (093875/Z/10/Z) and at Boehringer Ingelheim Pharma GmbH & Co. KG, Germany. We thank David Theobald, Johannes Freudenreich, Peter Schorn, Alfie Wearn and Benjamin Jaehnke for technical support and Gert Kramer, Dr. Holger Rosenbrock and Dr. Cornelia Dorner-Ciossek for helpful scientific discussions. The authors declare that the experiments performed in this manuscript followed the principles of laboratory animal care and are in compliance with the current laws of the UK and Germany.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00213-015-3984-

Remarks

Remarks from Jeffrey Robbins, a friend of Chief Justice Ralph D. Gants. He first met Ralph when they served together in the United States Attorney’s Office in Boston in the late 1980s

Alcohol-Preferring Rats Show Goal Oriented Behaviour to Food Incentives but Are Neither Sign-Trackers Nor Impulsive.

Drug addiction is often associated with impulsivity and altered behavioural responses to both primary and conditioned rewards. Here we investigated whether selectively bred alcohol-preferring (P) and alcohol-nonpreferring (NP) rats show differential levels of impulsivity and conditioned behavioural responses to food incentives. P and NP rats were assessed for impulsivity in the 5-choice serial reaction time task (5-CSRTT), a widely used translational task in humans and other animals, as well as Pavlovian conditioned approach to measure sign- and goal-tracking behaviour. Drug-naïve P and NP rats showed similar levels of impulsivity on the 5-CSRTT, assessed by the number of premature, anticipatory responses, even when the waiting interval to respond was increased. However, unlike NP rats, P rats were faster to enter the food magazine and spent more time in this area. In addition, P rats showed higher levels of goal-tracking responses than NP rats, as measured by the number of magazine nose-pokes during the presentation of a food conditioned stimulus. By contrast, NP showed higher levels of sign-tracking behaviour than P rats. Following a 4-week exposure to intermittent alcohol we confirmed that P rats had a marked preference for, and consumed more alcohol than, NP rats, but were not more impulsive when re-tested in the 5-CSRTT. These findings indicate that high alcohol preferring and drinking P rats are neither intrinsically impulsive nor do they exhibit impulsivity after exposure to alcohol. However, P rats do show increased goal-directed behaviour to food incentives and this may be associated with their strong preference for alcohol.There are errors in the Funding section. The correct funding information is as follows: The present study was funded by the Wellcome Trust and the Medical Research Council Programme (MRC Ref: G1002231 awarded to BJE, JWD, TWR, Wellcome Trust Ref: 093875/Z/10/Z), and the R24 Alcohol Research Resource Award grant (R24 AA015512) from NIAAA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final version of the article. It first appeared from PLoS via http://dx.doi.org/10.1371/journal.pone.013101

From Thinking to Religion: The Opening of Ideality in 19th Century Protestant Thought

In this essay, I argue for a philosophical continuity and progression to Protestant religious thought in the Nineteenth Century. More specifically, I center on the work of Immanuel Kant, Friedrich Schleiermacher, and Sören Kierkegaard, all of whom are Protestant Christians concerned with maintaining the worth of religion in a culture grown skeptical. The essay argues that it is the great value of Kierkegaard as a religious thinker that he provides a way beyond the conditions and strictures placed on thought by those defenders of faith\u27 who came before him. Kierkegaard does this by enfranchising a kind of thinking that might be called religious, and thus, makes the object of religious reflection not theology as a cognitive science, but a prayerfulness that makes possible a religious becoming

The role of sand lances (Ammodytes sp.) in the Northwest Atlantic ecosystem: a synthesis of current knowledge with implications for conservation and management

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Staudinger, M. D., Goyert, H., Suca, J. J., Coleman, K., Welch, L., Llopiz, J. K., Wiley, D., Altman, I., Applegate, A., Auster, P., Baumann, H., Beaty, J., Boelke, D., Kaufman, L., Loring, P., Moxley, J., Paton, S., Powers, K., Richardson, D., Robbins, J., Runge, J., Smith, B., Spiegel, C., & Steinmetz, H. The role of sand lances (Ammodytes sp.) in the Northwest Atlantic ecosystem: a synthesis of current knowledge with implications for conservation and management. Fish and Fisheries, 00, (2020): 1-34, doi:10.1111/faf.12445.The American sand lance (Ammodytes americanus, Ammodytidae) and the Northern sand lance (A. dubius, Ammodytidae) are small forage fishes that play an important functional role in the Northwest Atlantic Ocean (NWA). The NWA is a highly dynamic ecosystem currently facing increased risks from climate change, fishing and energy development. We need a better understanding of the biology, population dynamics and ecosystem role of Ammodytes to inform relevant management, climate adaptation and conservation efforts. To meet this need, we synthesized available data on the (a) life history, behaviour and distribution; (b) trophic ecology; (c) threats and vulnerabilities; and (d) ecosystem services role of Ammodytes in the NWA. Overall, 72 regional predators including 45 species of fishes, two squids, 16 seabirds and nine marine mammals were found to consume Ammodytes. Priority research needs identified during this effort include basic information on the patterns and drivers in abundance and distribution of Ammodytes, improved assessments of reproductive biology schedules and investigations of regional sensitivity and resilience to climate change, fishing and habitat disturbance. Food web studies are also needed to evaluate trophic linkages and to assess the consequences of inconsistent zooplankton prey and predator fields on energy flow within the NWA ecosystem. Synthesis results represent the first comprehensive assessment of Ammodytes in the NWA and are intended to inform new research and support regional ecosystem‐based management approaches.This manuscript is the result of follow‐up work stemming from a working group formed at a two‐day multidisciplinary and international workshop held at the Parker River National Wildlife Refuge, Massachusetts in May 2017, which convened 55 experts scientists, natural resource managers and conservation practitioners from 15 state, federal, academic and non‐governmental organizations with interest and expertise in Ammodytes ecology. Support for this effort was provided by USFWS, NOAA Stellwagen Bank National Marine Sanctuary, U.S. Department of the Interior, U.S. Geological Survey, Northeast Climate Adaptation Science Center (Award # G16AC00237), an NSF Graduate Research Fellowship to J.J.S., a CINAR Fellow Award to J.K.L. under Cooperative Agreement NA14OAR4320158, NSF award OCE‐1325451 to J.K.L., NSF award OCE‐1459087 to J.A.R, a Regional Sea Grant award to H.B. (RNE16‐CTHCE‐l), a National Marine Sanctuary Foundation award to P.J.A. (18‐08‐B‐196) and grants from the Mudge Foundation. The contents of this paper are the responsibility of the authors and do not necessarily represent the views of the National Oceanographic and Atmospheric Administration, U.S. Fish and Wildlife Service, New England Fishery Management Council and Mid‐Atlantic Fishery Management Council. This manuscript is submitted for publication with the understanding that the United States Government is authorized to reproduce and distribute reprints for Governmental purposes. Any use of trade, firm or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government