Effects of the 5-HT1a receptor agonist 8-OH-DPAT and other non-photic stimuli on the circadian rhythm of wheel-running activity in hamsters under different constant conditions

Cutrera, Rodolfo A.; Ouarour, Ali; Pévet, Paul

doi:10.1016/0304-3940(94)90654-8

Cited by 53 publications

(26 citation statements)

References 23 publications

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“…1, bottom panel), and even though cage cleaning actually appeared more arousing in DD-housed than in RR-housed animals. This result is consistent with our recent finding that saline injections induced significant phase advances during late subjective day in RR-housed but not in DD-housed animals (Rosenwasser et al, in press), and with other studies showing that a variety of non-photic phase shifting stimuli -including saline injections -may be effective only when animals are housed in constant light (Coleman and Francis, 1991;Cutrera et al, 1994). Two possible explanations for such results are: (1) incidental photic stimulation occurring during the delivery of the non-photic stimulus may antagonize non-photic phase shifting; or (2) Downloaded by [Simon Fraser University] at 07:14 20 November 2014 animals housed in constant light may show increased sensitivity to otherwise ineffective phase shifting stimuli, perhaps due to a reduced circadian amplitude.…”

Section: Discussionsupporting

confidence: 93%

Circadian Phase Shifting Associated with Routine Cage Maintenance: A Retrospective Analysis

Pellowski¹,

Rosenwasser²

1996

Biological Rhythm Research

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Stimuli that evoke behavioral activation can phase-shift free-running circadian activity rhythms in Syrian hamsters. Activation-induced phase shifting is characterized by a phase-response curve (PRC) that is dissimilar to the PRC for photic phase shifting, and recent studies indicate that complex interactions may occur between photic and non-photic phase shifting. Since animals in the laboratory may be exposed to both photic and behaviorally activating stimulation during routine cage maintenance procedures, we performed a retrospective analysis of possible phase shifts associated with cage cleaning in individually housed hamsters maintained in either constant darkness (DD) or dim red light (RR) during the course of an ongoing study of drug-induced phase shifting. All cage cleanings were conducted under RR and were separated from drug treatments by at least one week. The results indicated that both photic and non-photic phase shifts could be induced by routine cage maintenance procedures, depending on the circadian timing of the procedure, on lighting conditions, and on the degree of evoked activity.

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Section: Discussionsupporting

confidence: 93%

Circadian Phase Shifting Associated with Routine Cage Maintenance: A Retrospective Analysis

Pellowski¹,

Rosenwasser²

1996

Biological Rhythm Research

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“…This phenomenon is similar to that reported previously, where hamsters kept under LL for a longer duration (10 days) and then released to DD exhibited phase advances of similar magnitude (1). Also, hamsters housed under LL for periods long enough to promote free-running activity exhibited ϳ2-to 3-h phase-advance shifts in response to a variety of nonphotic stimuli, including control injections (8). We have reported that the large potentiating effects of brief LL exposure on 8-OH-DPAT phase-advance shifts at ZT 6 is lost after 3 days of LL exposure, owing largely to the increased shifting responses of controls masking the drug effect (24).…”

Section: Brief Constant Light Exposure Hypersensitizes Serotonergic Pmentioning

confidence: 99%

Serotonergic mediation of constant light-potentiated nonphotic phase shifting of the circadian locomotor activity rhythm in Syrian hamsters

Knoch

Siegel²,

Duncan³

et al. 2006

American Journal of Physiology-Regulatory, Integrative and Comp

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(1-3 days) constant light exposure (brief LL) potentiates nonphotic phase shifting induced by sleep deprivation and serotonin (5-HT) agonist stimulation. The present assessments reveal that exposure to brief LL markedly alters the magnitude and shape of the 5-HT 1A,7 receptor agonist, 8-(ϩ)2-dipropyl-amino-8-hydroxyl-1,2,3,4-tetrahyronapthalene (8-OH-DPAT) phase-response curve, facilitating (ϳ12 h) phase-advance shifts during the early morning when serotonergics have no phase-shifting effect. Brief LL also reduces the threshold for 8-OH-DPAT shifting at midday, evidenced by 5-to 6-h phase-advance shifts elicited by dosages that have no effect without the LL treatment. The brief LL-potentiated phase advances to intraperitoneal 8-OH-DPAT at zeitgeber time 0 (ZT 0) were blocked by the 5-HT 1A antagonists, pindolol and WAY 100635, indicating that this shifting is mediated by 5-HT 1A receptors. Antagonists with action at 5-HT7 receptors, including ritanserin and metergoline, were without effect. Although autoradiographic analyses of [ 3 H]8-OH-DPAT binding indicate that brief LL does not upregulate suprachiasmatic nucleus (SCN) 5-HT 1A receptor binding, intra-SCN microinjection of 8-OH-DPAT at ZT 0 in brief LL-exposed hamsters induced shifts similar to those produced by intraperitoneal injection, suggesting that SCN 5-HT 1A receptors mediate potentiated 8-OH-DPAT-induced shifts during the early morning. Lack of shifting by intra-SCN 8-OH-DPAT at ZT 6 or 18 (when intraperitoneal 8-OH-DPAT induces large shifts), further indicates that brief LL-potentiated shifts at these time points are mediated by 5-HT target(s) outside the SCN. Significantly, sleep deprivation-induced phase-advance shifts potentiated by brief LL (ϳ9 h) at ZT 0 were blocked by pindolol, suggesting that these behavioral shifts could be mediated by the same SCN 5-HT 1A receptor phase-resetting pathway as that activated by 8-OH-DPAT treatment. suprachiasmatic nucleus; sleep deprivation; 8-OH-DPAT THE SUPRACHIASMATIC NUCLEUS (SCN) of the anterior hypothalamus is the site of the master circadian clock in mammals (21,23,40,47). The SCN clock is entrained by photic input received principally from the retina via the retinohypothalamic tract and nonphotic signaling received from the intergeniculate leaflet via the geniculohypothalamic tract, and possibly from the midbrain raphe nuclei (28). Inputs from these nonphotic sources to the SCN are mediated by neuropeptide Y and serotonin (5-HT), respectively (34, 41).In Syrian hamsters, nonphotic stimuli, in the form of behavioral manipulations (e.g., social interaction, cage changing, novel wheel exposure, or sleep deprivation) or pharmacological intervention (e.g., 5-HT agonists or benzodiazepines) can induce phase shifts similar in magnitude to photic shifts (ϳ1-2 h) (15,31,36). Recently, we demonstrated that nonphotic shifting responses of hamsters receiving sleep deprivation treatment or systemic application of the 5-HT 1A,7 receptor agonist 8-OH-DPAT are greatly potentiated (ϳ10 -12 h) by prior treatment with s...

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“…Previous studies have also reported saline-induced phase advances during the late subjective day Meyer et al, 1993), and this effect has been attributed to handling and arousal since similar shifts were not seen when saline was delivered by a remote infusion system . Furthermore, a recent study showed that several nonphotic stimuli, including saline injections, produced daytime phase advances in constant light but not in constant darkness (Cutrera et al, 1994), as seen in the Downloaded by [North Carolina State University] at 06:22 10 April 2015 present study. The basis for this apparent interaction between non-photic phase shifting and background lighting has not yet been elucidated.…”

Section: Discussionmentioning

confidence: 50%

“…Thus the dark-pulse type PRC is commonly referred to as the "non-photic" PRC. A number of pharmacological agents, including serotonergic agonists (Medanic and Gillette, 1992;Tominaga et al, 1992;Edgar et al, 1993;Prosser et al, 1993;Cutrera et al, 1994), benzodiazepines (Turek and Losee-Olson, 1986;Wee and Turek, 1989a;Biello et al, 1991;Morin, 1991;Meyer et al, 1993), and neuropeptide Y (NPY) (Albers et al, 1991) can also induce phase shifts mimicking the non-photic PRC, either in behaving animals or in vitro preparations, or both. For some of these agents, phase shifts seen in behaving animals may be mediated by drug-induced behavioral activation (Van Reeth and Turek, 1989), but this does not appear true of all such agents .…”

Section: Introductionmentioning

confidence: 98%

Circadian phase shifting induced by clonidine injections in Syrian hamsters

Rosenwasser

Vogt

Pellowski

1995

Biological Rhythm Research

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The mammalian circadian pacemaker can be phase shifted by photic, pharmacological, and behaviorally-derived stimuli. The phase-response curves (PRCs) characterizing these diverse stimuli may comprise two distinct families; a photic PRC typified by the response to brief light pulses, and a nonphotic PRC, typified by the response to dark pulses and to behavioral activation. The present study examined the phase shifting effects of acute systemic treatment with the alpha2-adrenoceptor agonist, clonidine, in Syrian hamsters. Clonidine injections (0.25 mg/kg, ip) delivered during subjective night mimicked the phase shifting effects of light pulses in animals housed in both constant darkness (DD) and constant red light (RR), but similar effects were not seen in saline-treated controls. Both clonidine and saline injections resulted in phase advances during subjective day, but only in RRhoused animals. Clonidine-induced phase shifting was dose-dependent, but rather high doses were required to induce phase shifts. Pretreatment with the selective noradrenergic neurotoxin, DSP-4, blocked clonidine-induced phase shifting. These results suggest that clonidine acts at presynaptic alpha2-adrenergic autoreceptors to disinhibit spontaneous and/or evoked activity in the photic entrainment pathway.

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Effects of the 5-HT1a receptor agonist 8-OH-DPAT and other non-photic stimuli on the circadian rhythm of wheel-running activity in hamsters under different constant conditions

Cited by 53 publications

References 23 publications

Circadian Phase Shifting Associated with Routine Cage Maintenance: A Retrospective Analysis

Circadian Phase Shifting Associated with Routine Cage Maintenance: A Retrospective Analysis

Serotonergic mediation of constant light-potentiated nonphotic phase shifting of the circadian locomotor activity rhythm in Syrian hamsters

Circadian phase shifting induced by clonidine injections in Syrian hamsters

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