Related by context. Frequent words. (Click for all words.) 83 circadian rhythm 77 circadian 77 circadian clock 62 metabolism 62 melatonin 59 metabolic 57 serotonin 57 wakefulness 56 leptin 55 metabolic pathways 55 signaling pathways 53 glucose metabolism 53 sleep deprived 53 signaling pathway 52 physiological 52 SIRT1 52 ghrelin 51 sleep 51 Melatonin 51 protein synthesis 51 cortisol 50 cortisol levels 50 gene expression 50 molecular mechanisms 50 homeostasis 50 oscillations 49 epigenetic 49 adiponectin 49 molecular mechanism 49 transcription factors 49 hormonal 49 physiology 49 plasticity 49 mitochondria 49 cognition 49 biological pathways 49 REM sleep 49 genes 48 neurotransmitters 48 neurogenesis 48 ion channels 48 daytime sleepiness 48 menstrual cycles 48 Hormones 48 dopamine 48 sleep disorders 48 phosphorylation 48 signaling molecules 48 neurodegeneration 48 endocrine 47 immune responses 47 cognitive functions 47 physiologic 47 neurobiological 47 thyroid hormone 47 neurotransmitter 47 cognitive function 47 cytokine 47 innate immune system 46 neurons 46 hypothalamus 46 cognitive functioning 46 insulin resistance 46 synaptic 46 menstrual cycle 46 glutamate 46 stress hormones 46 inhibitory 46 sleepiness 46 transcription factor 46 receptors 46 astrocytes 46 proteins 45 hypoxia 45 adenosine 45 sleep disturbances 45 p# [001] 45 DNA methylation 45 microRNAs 45 mood disorders 45 secretion 45 BDNF 45 physiologically 45 Serotonin 45 autophagy 45 methylation 45 blood glucose levels 45 thyroid function 45 mammalian 45 satiety 45 seasonal affective disorder 45 overexpression 45 calorie restriction 44 neuronal 44 gut bacteria 44 synapses 44 neural 44 protein 44 immune cells 44 photoreceptors 44 skeletal muscle