Early Morning Behaviour Research Articles

Creeping in the night: What might ecologists be missing?

Wildlife activity patterns tend to be defined by terms such as diurnal and nocturnal that might not fully depict the complexity of a species’ life history strategy and behavior in a given system. These activity pattern categories often influence the methodological approaches employed, including the temporal period of study (daylight or nighttime). We evaluated banded mongoose (Mungos mungo) behavior in Northern Botswana through the use of remote sensing cameras at active den sites in order to characterize early morning behavior for this diurnal species. Our approach, however, provided the facility to capture unexpected nocturnal activity in a species that had otherwise only been studied during daylight hours. Camera traps were deployed for 215 trap days (24 hour data capture period) at den sites, capturing 5,472 photos over all events. Nocturnal activity was identified in 3% of trap days at study den sites with both vigilant and non-vigilant nocturnal behaviors identified. While vigilant behaviors involved troop fleeing responses, observations of non-vigilant behaviors suggest nonresident mongoose may investigate den sites of other troops during nocturnal time periods. There was no association between the occurrence of nocturnal activity and lunar phase (Fisher’s exact test, n = 215, p = 0.638) and thus, increased moonlight was not identified as a factor influencing nocturnal behavior. The drivers and fitness consequences of these nocturnal activities remain uncertain and present intriguing areas for future research. Our findings highlight the need for ecological studies to more explicitly address and evaluate the potential for temporal variability in activity periods. Modifying our approach and embracing variation in wildlife activity patterns might provide new insights into the interaction between ecological phenomenon and species biology that spans the diurnal–nocturnal spectrum.

Sleep Laboratory Study on Single and Repeated Dose Effects of Paroxetine, Alprazolam and Their Combination in Healthy Young Volunteers

Aims: To evaluate the potential interaction of 20 mg paroxetine and 1 mg alprazolam (early morning once-daily administration) on polysomnographic (PSG) sleep and subjective sleep and awakening quality, both after a single intake and after reaching a steady-state concentration. Methods: Twenty-two (11 for the PSG) healthy young volunteers of both sexes with no history of sleep disturbances (Pittsburgh Sleep Quality Index <5) participated in a double-blind, double-dummy, placebo-controlled, repeated-dose, 4-period, cross-over study. All volunteers received all 4 treatment sequences: paroxetine–alprazolam placebo (PAP); paroxetine placebo–alprazolam (PPA); paroxetine–alprazolam (PA), and paroxetine placebo–alprazolam placebo (PLA), in a randomized order. Each treatment was administered over 15 consecutive days, with a treatment-free interval of 7 days prior to the subsequent study period. In each experimental period, one PSG sleep study was performed on the 1st night (single-dose effects) and another study was performed on the 15th night (repeated-dose effects). Additionally, two other PSG studies were assessed: an adaptation recording, and a control night recording. All-night PSG recordings were obtained following standard procedures. Each 30-second period was scored according to the criteria of Rechtschaffen and Kales by means of an automatic sleep analysis system: Somnolyzer 24x7^TM. A self-rating scale for sleep and awakening quality and early morning behavior was completed no later than 15 min after awakening over the 15 days of each experimental intervention. General lineal models (treatment/time) were applied separately to each variable. Results: (1) No significant effects were observed in any sleep variables when control nights were compared with the 1st night with PLA. (2) Sleep continuity: After PAP a clear awakening effect was seen both in the first and second evaluations, mainly in wake time, movement time, number of awakenings and stage-1 duration. After PPA an evident hypnotic effect was observed on night 1. This effect was mainly observed in maintenance variables and slightly in sleep initiation variables; it had decreased by night 15. After PA an intermediate behavior in the variables related to sleep continuity was seen, highlighting the absence of the tolerance phenomenon observed when PPA was administered alone. (3) Sleep architecture: The most important effects in REM sleep were observed after PAP; an increase in REM latency and decreases in REM sleep. PAP also induced decreases in the number of non-REM and REM periods and increases in the average duration of non-REM periods and sleep cycles. PA presented a similar pattern to PAP, and PPA similar to PLA. In relation to non-REM sleep, PA showed more stage-2 and less slow-wave sleep (SWS). (4) Subjective perception: No significant differences were observed between treatments while they were being taken, but impairments in subjective sleep quality, awaking quality, latency and efficiency were seen, mainly after PA but also after PPA discontinuations. Conclusion: The combination of PAP and PPA presented an intermediate pattern in relation to sleep continuity, with less awaking effect than PAP alone and less hypnotic effect than PPA alone, and without developing tolerance. The PAP and PPA combination also showed a similar effect to PAP on REM sleep and was the treatment with the longest stage 2 and shortest SWS. No subjective sleep and awakening effects were seen during drug intake but subjective withdrawal reports were seen after abrupt interruption. The high agreement rate for the epoch-by-epoch comparison between automatic and human scoring confirms the validity of the Somnolyzer 24x7 and thus facilitates sleep studies in neuropsychopharmacological research.

Regional contrast in morning transitions observed during the 1999 Southern Oxidants Study Nashville/Middle Tennessee Intensive

This study investigates the impact of surface heterogeneity on the timing of the morning transitions observed during the 1999 Southern Oxidants Study Nashville/Middle Tennessee Intensive (SOS99N). The end of the morning transition occurs at a measurement site located in the Cumberland River Valley approximately 8 km northeast of downtown Nashville, on average, 1.25 h earlier than at three rural sites surrounding Nashville. This study shows that the early morning behavior of the boundary layers observed at the river valley site is dominated by local terrain features, whereas a previous study showed that the afternoon boundary layers observed at this site are more strongly influenced by its urban characteristics. Profiles of backscatter intensity recorded by monostatic sodars and Doppler wind profilers are analyzed to provide the evolution of boundary layer depth on days when a nocturnal inversion formed. These measurements indicate that the early morning growth rate of the convective boundary layer was faster, on average, at the river valley site in Nashville than at a rural, non‐river valley site where similar measurements were made (125 m h−1 versus 73 m h−1 from 0600 to 0800 h CST). A comparison of temperature profiles measured with radio acoustic sounding systems indicates that low‐level stability resulting from the nocturnal boundary layer had a stronger influence than surface energetics on the observed variations in boundary layer depth and morning transition end times. A single case study is shown to demonstrate the potential impact of the morning transition on gas phase chemistry measurements collected at a rural site. Case study and diurnally averaged time series show how surface‐layer humidity can be an effective tracer for diagnosing the end of the morning transition.

The effects of lormetazepam on aspects of memory, sleep and human performance

AbstractThe effects of lormetazepam 1 mg, 1·5 mg, 2 mg, a verum—triazolam 0·5 mg and placebo were examined in ten normal female volunteers, on tests of psychomotor function, performance and analogue rating scales for subjective sedation, sleep and early morning behaviour. Results showed all doses of lormetazepam to be effective hypnotics and free from residual effects 10 h after drug ingestion when tested on critical flicker fusion threshold (CFF), choice reaction time (CRT), simultated car tracking task and Maddox wing. Acquisition and immediate recall of word lists was poorer following administration of lormetazepam 1·5 mg and triazolam 0·5 mg. On memory scanning, lormetazepam 1 mg was the only dose completely free from residual impairment 10 h following administration.

Recent advances in the clinical pharmacology of benzodiazepines part II: Pharmacodynamics

AbstractTranquilizers, and specifically benzodiazepines (BZD), have become one of the most widely used group of drugs in the world; some have suggested too widely used. Interest in these drugs in still extremely high, both from the scientific and sociological point of view. This is best documented by the fact that the present review is based on more than 700 articles published between 1981 and 1984 covering various aspects of clinical pharmacology. Pharmacodynamic studies are mostly concerned with effects of the drug on the central nervous system (CNS), as well as on behavious and neuroendocrine functions. The former include computer‐assisted quantitative analyses of the scalp‐recorded wake electroencephalogram (EEG), based on which it seems possible to determine if, how, when and at what dose a newly developed compound affects the human brain. Sleep investigations are now concerned not only with the effect of the drug on the all‐night sleep, but also on the quality of awakening and early morning behaviour as well as with residual effects during daytime, affecting amnestic and cognitive functions, psychomotor performance (specifically in regard to driving ability), as well as mood and affectivity. Finally, for almost a decade increasing concern has been expressed about the widespread use of tranquillizers in society. Scientific evidence concerning thiss issue will be reviewed so that an appropriate medical decision may be reached for the treatment of the individual patients after consideration of the beneficial effects as well as undesirable side‐effects.

Recent advances in the clinical pharmacology of benzodiazepines part I: Pharmacokinetics

AbstractTranquillizers, and specifically benzodiazepines (BZD), have become one of the most widely used group of drugs in the world; some have suggested too widely used. Interest in these drugs is still extremely high, both from the scientific and sociological point of view. This is best documented by the fact that the present review is based on more than 700 articles published between 1981 and 1984 covering various aspects of clinical pharmacology. Pharmacokinetic studies dealing with absorption, metabolism and elimination after acute and chronic administration demonstrate that the onset and duration of action of BZD after single oral doses depend largely on absorption rate and the rate and extent of distribution. The rate and extent of accumulation during multiple dosage depend on the elimination half‐life and clearance. A framework is proposed for classification of BZD according to the elimination half‐life. Various factors — such as age, sex, disease state and drug interaction — influence the pharmacokinetic properties of BZD. Pharmacodynamic studies are mostly concerned with effects of the drug on the central nervous system (CNS), as well as on behaviour and neuroendocrine functions. The former include computer‐assisted quantitative analyses of the scalp‐recorded wake electroencephalogram (EEG), based on which it seems possible to determine if, how, when and at what dose a newly developed compound affects the human brain. Sleep investigations are now concerned not only with the effect of the drug on the all‐night sleep, but also on the quality of awakening and early morning behaviour as well as with residual effects during daytime, affecting mnestic and cognitive functions, psychomotor performance (specifically in regard to driving ability), as well as mood and affectivity. Finally, for almost a decade increasing concern has been expressed about the widespread use of tranquillizers in society. Scientific evidence concerning this issue will be reviewed so that an appropriate medical decision may be reached for the treatment of the individual patients after consideration of the beneficial effects as well as undesirable side‐effects.

Light treatment in depressive illness. Polysomnographic, psychometric and neuroendocrinological findings.

Objective and subjective quality of sleep and awakening as well as circadian rhythms in cortisol, temperature and well-being were investigated in 10 female hospitalized depressed patients diagnosed as major depressive disorders according to RDC criteria before (baseline), during (intervention) and after (recovery) treatment with biologically active or bright light (BL) and were compared with the findings in 10 normals. Polysomnographic evaluation demonstrated in depressed patients an increased sleep latency, decreased total sleep time, attenuated S4 and augmented REM sleep, as well as a shortened REM latency and a statistically significant increased average REM length as compared with normals. BL tended to shorten sleep onset, decrease number of awakenings, increase REM latency and significantly attenuated the average REM length. Subjective sleep quality tended to improve as did the subjective awakening quality after the recovery night. There was, however, a statistically significant improvement of the objectively evaluated quality of awakening and early morning behavior characterized by an improved attention, reaction time and performance in the reaction time task, while concentration and psychomotor activity tended to improve as as well. BL effects were also seen in hormonal secretion patterns: circadian cortisol secretion maxima occurred earlier in depressed patients than in normals before and after BL treatment, while during BL intervention this difference disappeared. Circadian temperature rhythms did not exhibit any significant findings with the exception of an earlier occurring minimum in depressed patients than in normals after treatment. Finally, subjective well-being as rated by means of an analogue scale was significantly worse in depressed patients than normals before but not during and after light treatment. The findings are discussed.

Subjective aspects of the effects of benzodiazepines on sleep and early morning behaviour

Subjective aspects of the effects of benzodiazepines on sleep and early morning behaviour

The Leeds Sleep Evaluation Questionnaire in psychopharmacological investigations - a review.

The Leeds Sleep Evaluation Questionnaire comprises ten self-rating 100-mm-line analogue questions concerned with aspects of sleep and early morning behaviour. The questionnaire has been used to monitor subjectively perceived changes in sleep during psychopharmacological investigations involving a variety of psychoactive agents, including sedative-hypnotics, antidepressants, anxiolytics, CNS stimulants, and antihistamines. Dose-related improvements in the self-reported ratings of getting to sleep and perceived quality of sleep were generally associated with reductions in the self-reported levels of alertness and behavioural integrity the morning following the nocturnal administration of sedative hypnotic and anti-anxiety agents. Psychostimulants on the other hand, impaired subjective ratings of sleep and produced increases in early morning assessments of alertness. Certain antidepressant and antihistaminic agents produced effects similar to the sedative-hypnotics, while others did not affect self-reported aspects of sleep and early morning behaviour.

The role of physiological colour change in the thermoregulation of Austrolestes annulosus (Selys)(Odonata)

Observations of the early morning behaviour of A. annulosus and Ischnura heterosticta, two species which normally undergo daily physiological colour changes, show that both orient themselves perpendicularly to the direction of incident sunlight when perching and when in flight, as long as they remain in 'dark' colour phase. Accurately controlled experiments on eight A, annulosus show that mean gain in thoracic temperature attributed to dark-phase coloration is 0.23C after exposure to a radiation source similar in intensity and spectral composition to sunlight. However, a thoracic temperature gain of up to 15C may result from orientation to the sun on cloudless, windless mornings; under these conditions an oriented insect is able to forage for food c. 2 h earlier than a similar insect perched in the shade. Field experiments on A. annulosus reveal that receptors other than eyes are used to detect the direction of incident sunlight and that only dark-phase insects are able to do so rapidly enough to remain oriented in flight. It is suggested that dark-phase chromatophores, which have an underlying network of nerve axons insulated by large air sacs, are receptors of incident radiation, and that the temperature increase of dark chromatophores exposed to sunlight is sufficiently rapid to allow the insects to remain oriented in flight.