Related by context. Frequent words. (Click for all words.) 60 circadian 60 hormone melatonin 58 circadian clocks 56 circadian rhythms 56 melatonin 56 circadian rhythm 56 neuronal activity 55 reproductive hormones 55 circadian clock 55 hyperinsulinemia 53 brain lesions 53 arousals 53 biorhythms 53 L dopa 53 physiological mechanisms 52 thermoregulation 52 neuroendocrine 52 researchers hypothesize 52 Notch signaling 52 vasodilation 52 myelination 51 magnetic stimulation 51 overactivity 51 neurotransmitter serotonin 51 fatty acid metabolism 51 hypothalamic 50 overstimulation 50 Wnt signaling 50 BH4 50 hormone leptin 50 Seasonal Affective Disorder SAD 50 neuropeptides 50 homeostatic 49 neovascularization 49 uterine contractions 49 FGF# 49 electrical conduction 49 contractile 49 microcirculation 49 daytime sleepiness 49 pineal gland 49 platelet activation 49 corticosterone 49 neurochemicals 49 spermatogenesis 49 orexin 49 neurochemistry 49 glucocorticoid 49 cataract formation 49 restorative sleep 48 wakefulness 48 parasympathetic 48 mitochondrial function 48 ramelteon 48 chemical serotonin 48 fat oxidation 48 biological clocks 48 external stimuli 48 dyskinesias 48 remyelination 48 dietary restriction 48 sensorimotor 48 suppresses appetite 48 insulin secretion 48 muscle rigidity 48 endocannabinoid system 48 chronic sleep deprivation 48 glycemia 48 cortisol levels 48 biochemical processes 48 neurotransmitter dopamine 47 hypoxemia 47 brain circuitry 47 synaptic plasticity 47 metabolism 47 neural pathways 47 cholinergic 47 sleep disturbances 47 diurnal 47 Nrf2 47 seasonal affective disorder 47 Insulin resistance 47 phytoplankton blooms 47 glucose metabolism 47 QTc interval 47 autonomic nervous system 47 sleepiness 47 IGFBP 3 47 NMDA receptors 47 NKT cells 47 dysregulated 47 proinflammatory cytokines 46 adrenals 46 neural circuitry 46 Physiologically 46 mutant flies 46 Sir2 46 serum cholesterol 46 parkinsonism 46 serotonin 46 neural mechanisms