scholarly journals Circuit robustness to temperature perturbation is altered by neuromodulators

2017 ◽  
Author(s):  
Sara A. Haddad ◽  
Eve Marder
Keyword(s):  
High Temperatures ◽  
Temperature Perturbation ◽  
Seasonal Temperature ◽  
Cancer Borealis ◽  
Temperature Changes ◽  
Animal Diversity ◽  
Effects Of Temperature ◽  
Work Done ◽  
Phase Relationships ◽  
Pyloric Rhythm

SUMMARYIn the ocean, the crab, Cancer borealis, is subject to daily and seasonal temperature changes. Previous work, done in the presence of descending modulatory inputs, had shown that the pyloric rhythm of the crab increases in frequency as temperature increases, but maintains its characteristic phase relationships until it “crashes” at extreme high temperatures. To study the interaction between neuromodulators and temperature perturbations, we studied the effects of temperature on preparations from which the descending modulatory inputs were removed. Under these conditions the pyloric rhythm was destabilized. We then studied the effects of temperature on preparations in the presence of oxotremorine, proctolin, and serotonin. Oxotremorine and proctolin enhanced the robustness of the pyloric rhythm, while serotonin made the rhythm less robust. These experiments reveal considerable animal-to-animal diversity in their crash stability, consistent with the interpretation that cryptic differences in many cell and network parameters are revealed by extreme perturbations.

scholarly journals Episodic Bouts of Activity Accompany Recovery of Rhythmic Output By a Neuromodulator- and Activity-Deprived Adult Neural Network

2003 ◽  
Vol 90 (4) ◽  
pp. 2720-2730 ◽  
Author(s):  
Jason A. Luther ◽  
Alice A. Robie ◽  
John Yarotsky ◽  
Christopher Reina ◽  
Eve Marder ◽  
...  
Keyword(s):  
Neural Network ◽  
Neuronal Network ◽  
Recovery Process ◽  
Stomatogastric Ganglion ◽  
Cancer Borealis ◽  
Pyloric Network ◽  
Underlying Mechanisms ◽  
Over Time ◽  
Phase Relationships ◽  
Pyloric Rhythm

The pyloric rhythm of the stomatogastric ganglion of the crab, Cancer borealis, slows or stops when descending modulatory inputs are acutely removed. However, the rhythm spontaneously resumes after one or more days in the absence of neuromodulatory input. We recorded continuously for days to characterize quantitatively this recovery process. Activity bouts lasting 40–900 s began several hours after removal of neuromodulatory input and were followed by stable rhythm recovery after 1–4 days. Bout duration was not related to the intervals (0.3–800 min) between bouts. During an individual bout, the frequency rapidly increased and then decreased more slowly. Photoablation of back-filled neuromodulatory terminals in the stomatogastric ganglion (STG) neuropil had no effect on activity bouts or recovery, suggesting that these processes are intrinsic to the STG neuronal network. After removal of neuromodulatory input, the phase relationships of the components of the triphasic pyloric rhythm were altered, and then over time the phase relationships moved toward their control values. Although at low pyloric rhythm frequency the phase relationships among pyloric network neurons depended on frequency, the changes in frequency during recovery did not completely account for the change in phase seen after rhythm recovery. We suggest that activity bouts represent underlying mechanisms controlling the restructuring of the pyloric network to allow resumption of an appropriate output after removal of neuromodulatory input.

Seed germination ecology of the endemic Iberian winter annualsIberis pectinataandZiziphora aragonensis

2009 ◽  
Vol 19 (3) ◽  
pp. 155-169 ◽  
Author(s):  
Miguel Á. Copete ◽  
José M. Herranz ◽  
Pablo Ferrandis
Keyword(s):  
High Temperatures ◽  
Natural Habitat ◽  
Ex Situ ◽  
Seasonal Temperature ◽  
Temperature Changes ◽  
Germination Ecology ◽  
Physiological Dormancy ◽  
Seed Age ◽  
Winter Annual ◽  
Population Reinforcement

AbstractThe germination ecology of the winter annual Iberian endemicsIberis pectinataandZiziphora aragonensiswas investigated in order to better understand adaptations of rare species to their natural habitat and to improveex-situpropagation techniques and management of their habitat. Specifically, we analysed the following aspects: (1) influence of temperature, light conditions and seed age on germination patterns; (2) phenology of germination; (3) germinative response of buried seeds to seasonal temperature changes; and (4) temperature requirements for induction and breaking of secondary dormancy. Germination was substantially lower in darkness than with a photoperiod in both taxa, with this difference being more pronounced inZ. aragonensis. Freshly matured seeds showed conditional physiological dormancy, germinating at low and medium temperatures but not at high temperatures (28/14 and 32/18°C). Germination capability increased with time of dry storage in both species, suggesting the existence of non-deep physiological dormancy. Under greenhouse conditions, germination of both taxa was mostly concentrated in autumn (October–November), while spring percentages were less than 1% of total accumulated germination recorded during the study.I. pectinataandZ. aragonensisseeds buried and exposed to natural seasonal temperature variations in an unheated greenhouse came out of conditional dormancy in summer and re-entered it in winter, thus exhibiting an annual conditional dormancy/non-dormancy cycle. Dormant seeds of both species which were stratified at 28/14 or 32/18°C during an 8-week period, were non-dormant when they were subsequently incubated over a range of temperatures from 5 to 25/10°C. Non-dormant seeds were induced into dormancy when stratified at 5 or 15/4°C for 8 weeks, showing a particularly low germination response at high temperatures. Recommendations for wild-population reinforcement programmes and for the management of the natural habitat of both endemics are discussed.

scholarly journals Physiology of Sugar-Cane VII. Effects of Temperature, Photoperiod Duration, and Diurnal and Seasonal Temperature Changes on Growth and Ripening

1965 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
KT Glasziou ◽  
TA Bull ◽  
MD Hatch ◽  
PC Whiteman
Keyword(s):  
Sugar Cane ◽  
Temperature Effects ◽  
Interaction Effects ◽  
Seasonal Temperature ◽  
Night Temperature ◽  
Temperature Changes ◽  
Temperature Regimes ◽  
Controlled Environments ◽  
Effects Of Temperature ◽  
Period Duration

Independent and interaction effects of day and night temperature, photo-period duration, and diurnal thermoperiodicity were studied on sugar-cane grown under controlled environments. During the first 3 months of growth, day and night temperature effects were mainly additive, but at 6 months the interaction effects of all variables were numerous and complex. Many of the interaction effects could be attributed to increased responses to constant-temperature regimes with a 12-hr photoperiod. No evidence for thermoperiodicity requirements was found.

A parametrized model of seasonal temperature changes in lakes

1990 ◽  
Vol 5 (1) ◽  
pp. 12-25 ◽  
Author(s):  
S.S. Zilitinkevich ◽  
V.A. Rumyantzev
Keyword(s):  
Seasonal Temperature ◽  
Temperature Changes

scholarly journals The Seasonal Cycle of Blocking and Associated Physical Mechanisms in the Australian Region and Relationship with Rainfall

2013 ◽  
Vol 141 (12) ◽  
pp. 4534-4553 ◽  
Author(s):  
M. J. Pook ◽  
J. S. Risbey ◽  
P. C. McIntosh ◽  
C. C. Ummenhofer ◽  
A. G. Marshall ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Seasonal Cycle ◽  
Seasonal Temperature ◽  
Ocean Fronts ◽  
Temperature Changes ◽  
Physical Mechanisms ◽  
Australian Region ◽  
Continental Antarctica ◽  
Positive Correlations ◽  
Blocking Index

Abstract The seasonal cycle of blocking in the Australian region is shown to be associated with major seasonal temperature changes over continental Antarctica (approximately 15°–35°C) and Australia (about 8°–17°C) and with minor changes over the surrounding oceans (below 5°C). These changes are superimposed on a favorable background state for blocking in the region resulting from a conjunction of physical influences. These include the geographical configuration and topography of the Australian and Antarctic continents and the positive west to east gradient of sea surface temperature in the Indo-Australian sector of the Southern Ocean. Blocking is represented by a blocking index (BI) developed by the Australian Bureau of Meteorology. The BI has a marked seasonal cycle that reflects seasonal changes in the strength of the westerly winds in the midtroposphere at selected latitudes. Significant correlations between the BI at Australian longitudes and rainfall have been demonstrated in southern and central Australia for the austral autumn, winter, and spring. Patchy positive correlations are evident in the south during summer but significant negative correlations are apparent in the central tropical north. By decomposing the rainfall into its contributions from identifiable synoptic types during the April–October growing season, it is shown that the high correlation between blocking and rainfall in southern Australia is explained by the component of rainfall associated with cutoff lows. These systems form the cyclonic components of blocking dipoles. In contrast, there is no significant correlation between the BI and rainfall from Southern Ocean fronts.

scholarly journals Emission Characteristics of Fluorescent Labels with Respect to Temperature Changes and Subsequent Effects on DNA Microchip Studies

2005 ◽  
Vol 71 (10) ◽  
pp. 6453-6457 ◽  
Author(s):  
Wen-Tso Liu ◽  
Jer-Horng Wu ◽  
Emily Sze-Ying Li ◽  
Ezrein Shah Selamat
Keyword(s):  
Melting Curve ◽  
Melting Curve Analysis ◽  
Emission Characteristics ◽  
Fluorescent Labels ◽  
Temperature Dependent ◽  
Temperature Changes ◽  
Formamide Concentration ◽  
Effects Of Temperature ◽  
Microarray Studies ◽  
Texas Red

ABSTRACT The effects of temperature, salt concentration, and formamide concentration on the emission characteristics of commonly used fluorescent labels were evaluated on DNA microchips. The emission intensities of different fluorophores without hybridization were observed to vary, each to a different extent, to mainly temperature changes. Rhodamine red, TAMRA (tetramethylrhodamine), and dyes from the carbocyanide group exhibited the largest variations, and Texas Red and Oregon Green exhibited the smallest variations. This temperature dependency was shown to affect results obtained during melting curve analysis in DNA microarray studies. To minimize the bias associated with the temperature-dependent emission of different fluorescent labels, a normalization step was proposed.

The microeconomic effects of temperature changes

2021 ◽  
pp. 129389
Author(s):  
Wenjian He ◽  
Yu Cheng ◽  
Hongxiao Zhang ◽  
Fuqiang Guo ◽  
Huimiao Yu
Keyword(s):  
Temperature Changes ◽  
Effects Of Temperature

Comparative Effects of Temperature on the Sodium and Water Permeabilities of the Gills of a Stenohaline Freshwater Fish (Carassius Auratus) and a Stenohaline Marine Fish (Serranus Scriba, Serranus Cabrilla)

1972 ◽  
Vol 57 (2) ◽  
pp. 359-366 ◽  
Author(s):  
J. ISAIA
Keyword(s):  
Freshwater Fish ◽  
Marine Fish ◽  
Osmotic Gradient ◽  
Water Fluxes ◽  
Simple Diffusion ◽  
Temperature Changes ◽  
Diffusional Permeability ◽  
Effects Of Temperature ◽  
Sea Perch ◽  
Branchial Membrane

1. Comparative effects of temperature on the permeability of the gill to water and to sodium were studied in the marine sea perch Serranus and the freshwater goldfish Carassius. 2. The acclimation Q10 for the water fluxes is higher in the freshwater fish than in the marine fish. 3. In the goldfish the osmotic permeability (Pos) is greater than the diffusional permeability (Pdlf) at all acclimation temperatures, suggesting the presence of ‘waterfilled channels’ in the branchial membrane. In the sea perch, on the other hand, Pos/Pdlf is approximately 1, indicating that water movements probably occur by simple diffusion. 4. The permeabilities to water and to sodium are similar in the sea perch but very different in the goldfish. Considering these results together with those from a similar study on an elasmobranch, it would seem that the more perfect the semipermeability of the gill membrane and the weaker the transepithelial osmotic gradient, the greater is the branchial porosity. 5. Assuming that temperature changes do not cause modification of the branchial surface or relative permeabilities to water and to sodium the independence of the temperature-coefficient variations for water and for sodium indicates a certain dissociation between the movements of salt and of water, in the sea perch. In the goldfish, assuming a constant branchial surface and in view of the fact that Pos > Pdif the high temperature coefficients for the water fluxes suggest that the water in the ‘water-filled channels’ is in a highly organized state.

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