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Sensory Conflict Disrupts Activity of the Drosophila Circadian Network

View Article: PubMed Central - PubMed

ABSTRACT

Periodic changes in light and temperature synchronize the Drosophila circadian clock, but the question of how the fly brain integrates these two input pathways to set circadian time remains unanswered. We explore multisensory cue combination by testing the resilience of the circadian network to conflicting environmental inputs. We show that misaligned light and temperature cycles can lead to dramatic changes in the daily locomotor activities of wild-type flies during and after exposure to sensory conflict. This altered behavior is associated with a drastic reduction in the amplitude of PERIOD (PER) oscillations in brain clock neurons and desynchronization between light- and temperature-sensitive neuronal subgroups. The behavioral disruption depends heavily on the phase relationship between light and temperature signals. Our results represent a systematic quantification of multisensory integration in the Drosophila circadian system and lend further support to the view of the clock as a network of coupled oscillatory subunits.

No MeSH data available.


Related in: MedlinePlus

Locomotor Behavior during Sensory Conflict(A) Experimental regime in which environmental conditions followed 3 days of 12-hr:12-hr LD and TC (16:26°C) in-phase (I), 3 days of free run in DD at 26°C (II), 7 days of out-of-phase 12-hr:12-hr LD and TC (16:26°C) via 6-hr delay of LD (III), followed by 3 days of free run in DD at 26°C (IV).(B–D) Average actograms of wild-type (B) , cry02 (C) , and per01 (D) . Red asterisk denotes representative evening behavior in part I; blue asterisk denotes representative pseudo-evening behavior in part III. Clock-less per01flies show only brief startle responses to the sudden environmental changes and otherwise display arrhythmic behavior (C).See Figure S1 and S2 for individual fly data and genetic controls.
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fig1: Locomotor Behavior during Sensory Conflict(A) Experimental regime in which environmental conditions followed 3 days of 12-hr:12-hr LD and TC (16:26°C) in-phase (I), 3 days of free run in DD at 26°C (II), 7 days of out-of-phase 12-hr:12-hr LD and TC (16:26°C) via 6-hr delay of LD (III), followed by 3 days of free run in DD at 26°C (IV).(B–D) Average actograms of wild-type (B) , cry02 (C) , and per01 (D) . Red asterisk denotes representative evening behavior in part I; blue asterisk denotes representative pseudo-evening behavior in part III. Clock-less per01flies show only brief startle responses to the sudden environmental changes and otherwise display arrhythmic behavior (C).See Figure S1 and S2 for individual fly data and genetic controls.

Mentions: Wild-type flies (Canton S) and cry- mutants (cry02) were subjected to an environmental regime comprising aligned LD:TC (part I, ΔtL,T = 0 hr), followed by a 6-hr delay of LD with respect to TC (part III, ΔtL,T = 6 hr), interspersed or followed by free running conditions to assess stability of endogenous rhythms (part II and part IV, outlined in Figure 1A). As is standard practice for observing endogenous activity rhythms, free running conditions comprised constant darkness and constant warmth (26°C—Drosophila’s preferred ambient temperature [Sayeed and Benzer, 1996]) to mitigate any negative masking effect of cold temperatures on overall activity levels.


Sensory Conflict Disrupts Activity of the Drosophila Circadian Network
Locomotor Behavior during Sensory Conflict(A) Experimental regime in which environmental conditions followed 3 days of 12-hr:12-hr LD and TC (16:26°C) in-phase (I), 3 days of free run in DD at 26°C (II), 7 days of out-of-phase 12-hr:12-hr LD and TC (16:26°C) via 6-hr delay of LD (III), followed by 3 days of free run in DD at 26°C (IV).(B–D) Average actograms of wild-type (B) , cry02 (C) , and per01 (D) . Red asterisk denotes representative evening behavior in part I; blue asterisk denotes representative pseudo-evening behavior in part III. Clock-less per01flies show only brief startle responses to the sudden environmental changes and otherwise display arrhythmic behavior (C).See Figure S1 and S2 for individual fly data and genetic controls.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120367&req=5

fig1: Locomotor Behavior during Sensory Conflict(A) Experimental regime in which environmental conditions followed 3 days of 12-hr:12-hr LD and TC (16:26°C) in-phase (I), 3 days of free run in DD at 26°C (II), 7 days of out-of-phase 12-hr:12-hr LD and TC (16:26°C) via 6-hr delay of LD (III), followed by 3 days of free run in DD at 26°C (IV).(B–D) Average actograms of wild-type (B) , cry02 (C) , and per01 (D) . Red asterisk denotes representative evening behavior in part I; blue asterisk denotes representative pseudo-evening behavior in part III. Clock-less per01flies show only brief startle responses to the sudden environmental changes and otherwise display arrhythmic behavior (C).See Figure S1 and S2 for individual fly data and genetic controls.
Mentions: Wild-type flies (Canton S) and cry- mutants (cry02) were subjected to an environmental regime comprising aligned LD:TC (part I, ΔtL,T = 0 hr), followed by a 6-hr delay of LD with respect to TC (part III, ΔtL,T = 6 hr), interspersed or followed by free running conditions to assess stability of endogenous rhythms (part II and part IV, outlined in Figure 1A). As is standard practice for observing endogenous activity rhythms, free running conditions comprised constant darkness and constant warmth (26°C—Drosophila’s preferred ambient temperature [Sayeed and Benzer, 1996]) to mitigate any negative masking effect of cold temperatures on overall activity levels.

View Article: PubMed Central - PubMed

ABSTRACT

Periodic changes in light and temperature synchronize the Drosophila circadian clock, but the question of how the fly brain integrates these two input pathways to set circadian time remains unanswered. We explore multisensory cue combination by testing the resilience of the circadian network to conflicting environmental inputs. We show that misaligned light and temperature cycles can lead to dramatic changes in the daily locomotor activities of wild-type flies during and after exposure to sensory conflict. This altered behavior is associated with a drastic reduction in the amplitude of PERIOD (PER) oscillations in brain clock neurons and desynchronization between light- and temperature-sensitive neuronal subgroups. The behavioral disruption depends heavily on the phase relationship between light and temperature signals. Our results represent a systematic quantification of multisensory integration in the Drosophila circadian system and lend further support to the view of the clock as a network of coupled oscillatory subunits.

No MeSH data available.


Related in: MedlinePlus