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A Path to Sleep Is through the Eye(1,2,3).

Morin LP - eNeuro (2015)

Bottom Line: The visual input route is a practical avenue to follow in pursuit of the neural circuitry and mechanisms governing sleep and arousal in small nocturnal mammals and the organizational principles may be similar in diurnal humans.Photosomnolence studies are likely to be particularly advantageous because the timing of sleep is largely under experimenter control.Moreover, the experimental designs and associated results benefit from a substantial amount of existing neuroanatomical and pharmacological literature that provides a solid framework guiding the conduct and interpretation of future investigations.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Psychiatry and Graduate Program in Neuroscience, Stony Brook Medicine, Stony Brook University , Stony Brook, New York 11794.

ABSTRACT
Light has long been known to modulate sleep, but recent discoveries support its use as an effective nocturnal stimulus for eliciting sleep in certain rodents. "Photosomnolence" is mediated by classical and ganglion cell photoreceptors and occurs despite the ongoing high levels of locomotion at the time of stimulus onset. Brief photic stimuli trigger rapid locomotor suppression, sleep, and a large drop in core body temperature (Tc; Phase 1), followed by a relatively fixed duration interval of sleep (Phase 2) and recovery (Phase 3) to pre-sleep activity levels. Additional light can lengthen Phase 2. Potential retinal pathways through which the sleep system might be light-activated are described and the potential roles of orexin (hypocretin) and melanin-concentrating hormone are discussed. The visual input route is a practical avenue to follow in pursuit of the neural circuitry and mechanisms governing sleep and arousal in small nocturnal mammals and the organizational principles may be similar in diurnal humans. Photosomnolence studies are likely to be particularly advantageous because the timing of sleep is largely under experimenter control. Sleep can now be effectively studied using uncomplicated, nonintrusive methods with behavior evaluation software tools; surgery for EEG electrode placement is avoidable. The research protocol for light-induced sleep is easily implemented and useful for assessing the effects of experimental manipulations on the sleep induction pathway. Moreover, the experimental designs and associated results benefit from a substantial amount of existing neuroanatomical and pharmacological literature that provides a solid framework guiding the conduct and interpretation of future investigations.

No MeSH data available.


Related in: MedlinePlus

Mean simultaneously recorded activity indices (solid black lines; motion detected from video) and core body temperatures (broken red lines) for groups of mice injected with vehicle (VEH; A, B), methamphetamine (MA; C), modafinil (MOD; D), caffeine (CAF; E, F), 20 and 40 mg, respectively. The times of injection are indicated by the arrowhead and broken vertical line. The daylight period (white area) is to the left and dark period is to the right (shaded area). In A, no light pulse was administered. In B−F, a 5 min light pulse (vertical white area) began at time 0. The light-induced drop in mean locomotor activity and Tc is evident in B (double-headed arrow) and less so in E. Modified from Figures 5-7 in Vivanco et al. (2013); see for details.
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Figure 4: Mean simultaneously recorded activity indices (solid black lines; motion detected from video) and core body temperatures (broken red lines) for groups of mice injected with vehicle (VEH; A, B), methamphetamine (MA; C), modafinil (MOD; D), caffeine (CAF; E, F), 20 and 40 mg, respectively. The times of injection are indicated by the arrowhead and broken vertical line. The daylight period (white area) is to the left and dark period is to the right (shaded area). In A, no light pulse was administered. In B−F, a 5 min light pulse (vertical white area) began at time 0. The light-induced drop in mean locomotor activity and Tc is evident in B (double-headed arrow) and less so in E. Modified from Figures 5-7 in Vivanco et al. (2013); see for details.

Mentions: As emphasized by Pack et al. (2007) and Fisher et al. (2012), video-based analysis is particularly useful for testing sleep responses to pharmaceuticals. One example is a recent investigation that evaluated the effects of psychostimulant drugs on photosomnolence, as estimated from open-field locomotion (Vivanco et al., 2013). Each of three drugs administered to mice several hours prior to exposure to the photic test stimulus caused acute hyperactivity (Fig. 4). However, by the time of light exposure, the hyperactivity induced by modafinil or methamphetamine had ceased and the caffeine-induced hyperactivity of the third group had been replaced by significant hypoactivity. Most importantly, regardless of the level of activity at the time of light exposure, all three drugs prevented photosomnolence and the expected drop in Tc.


A Path to Sleep Is through the Eye(1,2,3).

Morin LP - eNeuro (2015)

Mean simultaneously recorded activity indices (solid black lines; motion detected from video) and core body temperatures (broken red lines) for groups of mice injected with vehicle (VEH; A, B), methamphetamine (MA; C), modafinil (MOD; D), caffeine (CAF; E, F), 20 and 40 mg, respectively. The times of injection are indicated by the arrowhead and broken vertical line. The daylight period (white area) is to the left and dark period is to the right (shaded area). In A, no light pulse was administered. In B−F, a 5 min light pulse (vertical white area) began at time 0. The light-induced drop in mean locomotor activity and Tc is evident in B (double-headed arrow) and less so in E. Modified from Figures 5-7 in Vivanco et al. (2013); see for details.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4596090&req=5

Figure 4: Mean simultaneously recorded activity indices (solid black lines; motion detected from video) and core body temperatures (broken red lines) for groups of mice injected with vehicle (VEH; A, B), methamphetamine (MA; C), modafinil (MOD; D), caffeine (CAF; E, F), 20 and 40 mg, respectively. The times of injection are indicated by the arrowhead and broken vertical line. The daylight period (white area) is to the left and dark period is to the right (shaded area). In A, no light pulse was administered. In B−F, a 5 min light pulse (vertical white area) began at time 0. The light-induced drop in mean locomotor activity and Tc is evident in B (double-headed arrow) and less so in E. Modified from Figures 5-7 in Vivanco et al. (2013); see for details.
Mentions: As emphasized by Pack et al. (2007) and Fisher et al. (2012), video-based analysis is particularly useful for testing sleep responses to pharmaceuticals. One example is a recent investigation that evaluated the effects of psychostimulant drugs on photosomnolence, as estimated from open-field locomotion (Vivanco et al., 2013). Each of three drugs administered to mice several hours prior to exposure to the photic test stimulus caused acute hyperactivity (Fig. 4). However, by the time of light exposure, the hyperactivity induced by modafinil or methamphetamine had ceased and the caffeine-induced hyperactivity of the third group had been replaced by significant hypoactivity. Most importantly, regardless of the level of activity at the time of light exposure, all three drugs prevented photosomnolence and the expected drop in Tc.

Bottom Line: The visual input route is a practical avenue to follow in pursuit of the neural circuitry and mechanisms governing sleep and arousal in small nocturnal mammals and the organizational principles may be similar in diurnal humans.Photosomnolence studies are likely to be particularly advantageous because the timing of sleep is largely under experimenter control.Moreover, the experimental designs and associated results benefit from a substantial amount of existing neuroanatomical and pharmacological literature that provides a solid framework guiding the conduct and interpretation of future investigations.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Psychiatry and Graduate Program in Neuroscience, Stony Brook Medicine, Stony Brook University , Stony Brook, New York 11794.

ABSTRACT
Light has long been known to modulate sleep, but recent discoveries support its use as an effective nocturnal stimulus for eliciting sleep in certain rodents. "Photosomnolence" is mediated by classical and ganglion cell photoreceptors and occurs despite the ongoing high levels of locomotion at the time of stimulus onset. Brief photic stimuli trigger rapid locomotor suppression, sleep, and a large drop in core body temperature (Tc; Phase 1), followed by a relatively fixed duration interval of sleep (Phase 2) and recovery (Phase 3) to pre-sleep activity levels. Additional light can lengthen Phase 2. Potential retinal pathways through which the sleep system might be light-activated are described and the potential roles of orexin (hypocretin) and melanin-concentrating hormone are discussed. The visual input route is a practical avenue to follow in pursuit of the neural circuitry and mechanisms governing sleep and arousal in small nocturnal mammals and the organizational principles may be similar in diurnal humans. Photosomnolence studies are likely to be particularly advantageous because the timing of sleep is largely under experimenter control. Sleep can now be effectively studied using uncomplicated, nonintrusive methods with behavior evaluation software tools; surgery for EEG electrode placement is avoidable. The research protocol for light-induced sleep is easily implemented and useful for assessing the effects of experimental manipulations on the sleep induction pathway. Moreover, the experimental designs and associated results benefit from a substantial amount of existing neuroanatomical and pharmacological literature that provides a solid framework guiding the conduct and interpretation of future investigations.

No MeSH data available.


Related in: MedlinePlus