title: Involvement of the α1-adrenoceptor in sleep-waking and sleep loss-induced anxiety behavior in zebrafish.
abstract: Sleep is a universal phenomenon in vertebrates, and its loss affects various behaviors. Independent studies have reported that sleep loss increases anxiety; however, the detailed mechanism is unknown. Because sleep deprivation increases noradrenalin (NA), which modulates many behaviors and induces patho-physiological changes, this study utilized zebrafish as a model to investigate whether sleep loss-induced increased anxiety is modulated by NA. Continuous behavioral quiescence for at least 6s was considered to represent sleep in zebrafish; although some authors termed it as a sleep-like state, in this study we have termed it as sleep. The activity of fish that signified sleep-waking was recorded in light-dark, during continuous dark and light; the latter induced sleep loss in fish. The latency, number of entries, time spent and distance travelled in the light chamber were assessed in a light-dark box test to estimate the anxiety behavior of normal, sleep-deprived and prazosin (PRZ)-treated fish. Zebrafish showed increased waking during light and complete loss of sleep upon continuous exposure to light for 24h. PRZ significantly increased sleep in normal fish. Sleep-deprived fish showed an increased preference for dark (expression of increased anxiety), and this effect was prevented by PRZ, which increased sleep as well. Our findings suggest that sleep loss-induced anxiety-like behavior in zebrafish is likely to be mediated by NA's action on the α1-adrenoceptor.
authors.affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
authors.forename: A
authors.initials: A
authors.lastname: Singh
authors.forename: N
authors.initials: N
authors.lastname: Subhashini
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.forename: B N
authors.initials: BN
authors.lastname: Mallick
mesh_terms: D000818:Animals; D001007:Anxiety / Q000503:physiopathology* / Q000523:psychology; D003624:Darkness; D008027:Light; D009043:Motor Activity / Q000502:physiology*; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology* / Q000523:psychology; D014851:Wakefulness / Q000502:physiology*; D015027:Zebrafish
chemical_list: D018340:Receptors, Adrenergic, alpha-1