Table 2.
Sleep- and circadian-related characters that emerged as a correlated response to selection.
| Organism | Selected trait | Starting population | Selection intensity (%)a | No. Generations of selection | High Trait |
Low Trait |
Trait(s) with correlated response | Ref. |
|---|---|---|---|---|---|---|---|---|
| D. melanogaster | Starvation resistance | Wild-collected Terhune Orchards, Princeton, NJ, USA | 15 | 80 | 18 days | – | Day and night sleep duration | [56] |
| Mus musculus | Immobility in tail suspension testb | CD1 mice | Fixed criteria: High immobility (>115 s); low immobility (<35 s) | 14 | 100% >115s | 100% < 35s |
Light SWS, REM sleep latency, wakefulness, sucrose consumption, seric corticosterone and brain 5HT levels, 8-OH-DPAT-induced hypothermia, DRN firing inhibition, response to antidepressants | [58] |
| Mus musculus | Stress reactivity (corticosterone level after restraint stress) | CD-1 outbred mice | 8 | 7 | Median 13.0 male/26.9 female (ng/ml) | Median 1.5 male/7.2 female (ng/ml) | Percentage of time in wake, REM, and NREM; transition frequency between wake and sleep states; EEG frequency power | [62] |
| Rattus norvegicus | Sensitivity to diisopropyl fluorophosphate (DFP)d | Sprague–Dawley | – | 9 | – | – | Increased REM, reduced REM onset, advanced circadian phase, body temperature, drinking behavior | [59, 60] |
| Rattus norvegicus | Intake of 10% alcohol per body weight | Sprague–Dawley, Wistar, Long-Evans | – | 8–51 | 0.48 ± 0.25 in males; 0.97 ± 0.34 in femalesc | 0.18 ± 0.13 in males; 0.29 ± 0.26 in femalesc | Increased time in sleep–wake stages | [61, 63] |
| Rattus norvegicus | Righting reflex after intraperitoneal injection of GHB 1 g/kg | Ratio of sleep duration/onset of loss of righting reflex ≥ 8 sensitive; ≤ 2 resistant |
10 | 13.2 in males; 16.5 in females | 0.2 in males; 0.5 in females | [36] | ||
| Canis familiaris | Brachycephaly | – | – | – | – | – | Sleep-disordered breathing index; nadir in O2 saturation | [37] |
aHere selection intensity refers to the proportion of flies selected as parents for the next generation.
bImmobility in the tail suspension test is a model for depression. DRN, dorsal raphe nucleus.
cml alcohol consumed per 100 g of body weight.
dSensitivity was defined from a composite score of changes in body temperature, drinking behavior, and body weight.