Effect of sleep deprivation on dopamine receptor function in normal subjects

The Birth of the Mammalian Sleep

Simple Summary

Mammals evolved from reptiles as a consequence of an evolutionary bottleneck. Some diurnal reptiles extended their activity, first to twilight and then to the entire dark time. This forced the change of the visual system. Pursuing maximal sensitivity, they abandoned the filters protecting the eyes against the dangerous diurnal light, which, in turn, forced immobility in lightproof burrows during light time. This was the birth of the mammalian sleep. Then, the Cretacic-Paleogene extinction of dinosaurs leaved free the diurnal niche and allowed the expansion of a few early mammals to diurnal life and the high variability of sleep traits. On the other hand, we propose that the idling rest is a state showing homeostatic regulation. Therefore, the difference between behavioral rest and wakeful idling is rather low: both show quiescence, raised sensory thresholds, reversibility, specific sleeping-resting sites and body positions, it is a pleasing state, and both are dependent of circadian and homeostatic regulation. Indeed, the most important difference is the unconsciousness of sleep and the consciousness of wakeful idling. Thus, we propose that sleep is a mere upgrade of the wakeful rest, and both may have the same function: guaranteeing rest during a part of the daily cycle.

Abstract

Mammals evolved from small-sized reptiles that developed endothermic metabolism. This allowed filling the nocturnal niche. They traded-off visual acuity for sensitivity but became defenseless against the dangerous daylight. To avoid such danger, they rested with closed eyes in lightproof burrows during light-time. This was the birth of the mammalian sleep, the main finding of this report. Improved audition and olfaction counterweighed the visual impairments and facilitated the cortical development. This process is called “The Nocturnal Evolutionary Bottleneck”. Pre-mammals were nocturnal until the Cretacic-Paleogene extinction of dinosaurs. Some early mammals returned to diurnal activity, and this allowed the high variability in sleeping patterns observed today. The traits of Waking Idleness are almost identical to those of behavioral sleep, including homeostatic regulation. This is another important finding of this report. In summary, behavioral sleep seems to be an upgrade of Waking Idleness Indeed, the trait that never fails to show is quiescence. We conclude that the main function of sleep consists in guaranteeing it during a part of the daily cycle.

Schizophrenia: the role of sleep and circadian rhythms in regulating dopamine and psychosis

Schizophrenia has long been associated with abnormalities in circadian rhythms and sleep. Up until now, there have been no thorough reviews of the potential mechanisms behind the myriad of circadian and sleep abnormalities observed in schizophrenia and psychosis. We present evidence of sleep playing an important role in psychosis predominantly mediated by dopaminergic pathways. A synthesis of both human and animal experimental work suggests that the interplay between sleep and dopamine is important in the generation and maintenance of psychosis. In particular, both animal and human data point to sleep disruption increasing dopamine release and sensitivity. Furthermore, elevated dopamine levels disrupt sleep and circadian rhythms. The synthesis of knowledge suggests that circadian rhythms, dopamine dysregulation, and psychosis are intricately linked. This suggests that treatment of circadian disturbance may be a useful target in improving the lives and symptoms of patients with schizophrenia.

Attention deficit hyperactivity disorder symptomatology and pediatric obesity: Psychopathology or sleep deprivation?

The relationship between attention deficit hyperactivity disorder (ADHD) and obesity in children has received considerable attention in recent years. However, the literature currently overlooks the potential causal and maintaining role that sleep problems may play in this relationship. Using a biopsychosocial framework, this article highlights how sleep problems impact the biological, psychological, and social aspects of both ADHD symptomatology and obesity. An in-depth examination of this model illustrates the imperative need for future research and clinical practice to recognize and explore the role sleep has in the link between obesity and ADHD symptomatology.

Sleep patterns and the risk for ADHD: a review

Attention-deficit/hyperactivity disorder (ADHD) is often associated with comorbid sleep disturbances. Sleep disturbances may be a risk factor for development of the disorder, a symptom of the disorder, or a comorbid condition affected by a similar psychopathology. Various studies have examined the impact of sleep deprivation on the presence/exacerbation of ADHD symptomology, as well as longitudinal and concurrent associations between different sleep disturbances and ADHD, yet the notion of sleep disturbances as a predecessor to ADHD remains unclear. As such, this review examines the evidence for sleep disturbances as a risk factor for the development of ADHD, as well as the mechanisms underlying the association between sleep patterns and ADHD. Additionally, clinical implications regarding the comorbid nature of sleep disturbances and ADHD will be considered.

Effects of acute sleep restriction on behavior, sustained attention, and response inhibition in children

This study examined the effects of acute sleep restriction on the day-time behavior and performance of healthy children and adolescents. 82 participants (8 to 15 years of age) completed 5 nights of baseline sleep and were randomly assigned to Optimized (10 hr.) or Restricted (4 hr.) sleep for an overnight lab visit. Behavior, performance, and sleepiness were assessed the following day. Sleep restriction was associated with shorter daytime sleep latency, increased subjective sleepiness, and increased sleepy and inattentive behaviors but was not associated with increased hyperactive-impulsive behavior or impaired performance on tests of response inhibition and sustained attention. Results are discussed in terms of current theories regarding effects of inadequate or disturbed sleep among children and adolescents.

Sleep deprivation therapy in depressive illness and Parkinson's disease

1. Sleep deprivation is commonly associated with feelings of fatigue and cognitive impairment. 2. Patients with depressive illness, however, often experience mood improvements under these same conditions. 3. Other studies now show that tremor and rigidity, in patients with Parkinson's disease, are also improved by sleep depression therapy. 4. The neural substrates which underlie these effects are unclear. Some recent evidence, however, suggests that sleep deprivation may activate mechanisms which are otherwise typical of conditions of metabolic stress. 5. A common feature of these mechanisms is the suppression of cholinergic activity which is thought to be excessive, in relation to monoamine transmission, in both depression and Parkinson's disease.

Effect of sleep deprivation on the growth hormone response to the alpha-3 adrenergic receptor agonist, clonidine, in normal subjects

One night's sleep deprivation (SD) increased the growth hormone (GH) response to clonidine (20 ug/kg i.v.) in 11 normal men ( p < 0.005). This finding may indicate that SD enhances alpha-2 adrenergic receptor function or that the GH response to GH releasing factor in increased by SD.

Potential role of serum prolactin measurement in the diagnosis of late posttraumatic seizures. A case report

Posttraumatic seizures are an important medical complication after traumatic brain injury. However, the diverse clinical presentation of posttraumatic seizures, combined with the cognitive and behavior deficits frequently seen in this patient population, can make the diagnosis of posttraumatic seizures particularly challenging. Electroencephalography and imaging studies are often abnormal and nonspecific. It has been reported that serum prolactin levels frequently rise after epileptic seizures. This case report describes the use of prolactin measurement to confirm two suspected posttraumatic seizure episodes in a 42-yr-old male with severe traumatic brain injury. Each episode lasted less than 1 min and involved conspicuously altered postural tone and respiratory pattern, followed by a change in verbal and motor responsiveness. No rhythmic extremity movements were observed. Diagnostic evaluation included electroencephalography and imaging studies, which demonstrated nonspecific abnormalities. Serum prolactin levels obtained within 20 to 40 min were markedly elevated and two to three times greater than the baseline level. The use of prolactin levels in the diagnosis of posttraumatic seizures is reviewed, accompanied by discussion of pertinent aspects of normal and abnormal states of prolactin secretion and regulation.

Antidepressant responses and changes in visual adaptation after sleep deprivation

The effects of 1 night of total sleep deprivation on mood state and visual light-dark adaptation were studied in 15 patients with major depression and nine normal comparison subjects. Mood improvements were evident in all but one patient, although responders (n = 9) could be easily distinguished from nonresponders (n = 6). No significant group differences were found in ocular responses before treatment. After treatment, however, light-adapted peak corneofundal potentials increased in patient responders and decreased in patient nonresponders and normal subjects. Moreover, changes in peak values were closely correlated (r = -0.74) with changes in scores on the Hamilton Depression Rating Scale. In contrast, dark-adapted trough potentials did not distinguish between diagnostic groups and were not correlated with clinical responses. The results indicate that sleep deprivation induces changes in light sensitivity that are proportional to improvements in depressive state.

The effect of sleep deprivation on motor impairment and retinal adaptation in Parkinson's disease

1. Sleep deprivation has previously been reported to result in a temporary improvement of motor deficits in Parkinson's disease patients. 2. The mechanism of this action is unclear but may involve an activation of dopamine pathways. 3. Other studies suggest that light adaptive changes in the retinal pigment epithelium may serve as a model of dopamine sensitivity. 4. The present study examined the effects of one night of total sleep deprivation on RPE potentials and motor abnormalities in Parkinson's patients. 5. Sleep deprivation significantly improved motor deficits and these changes were strongly correlated with increases in light adaptive RPE potentials.

Single photon emission computerized tomography assessment of cerebral dopamine D2 receptor blockade in depression before and after sleep deprivation--preliminary results

The antidepressant properties of total sleep deprivation (TSD) have been well established. There is some evidence that TSD may improve depression by altering central dopamine (DA) function. We therefore studied five depressed TSD responders and five TSD nonresponders after sleep and after TSD and five controls after sleep with IBZM single photon emission computerized tomography (SPECT). Responders showed a significant decrease (Wilcoxon--test p < 0.05) of relative basal ganglia D2 receptor occupancy after TSD compared to nonresponders (change score responders versus nonresponders p < 0.05, U-test). The data are interpreted as a sign of an enhanced DA release in responders. The results confirm previous hypotheses of dopaminergic involvement in the therapeutic action of TSD and indirectly support a dopamine hypotheses of depression.

Increased sensitivity of dopamine receptors and recurrence of affective psychosis after childbirth

OBJECTIVE

To test the hypothesis that affective psychosis after childbirth is associated with an altered sensitivity to dopaminergic stimulation.

DESIGN

Prospective study of pregnant women at high risk of developing an affective psychosis after childbirth. Clinical assessments in pregnancy and after delivery were made by using a semistructured interview (schedule for affective disorders and schizophrenia) and psychiatric illnesses were categorised according to operational criteria (research diagnostic criteria).

SETTING

Obstetric and psychiatric departments in and around Greater London.

SUBJECTS

29 pregnant women with a history of bipolar or schizoaffective psychosis and 47 control pregnant women. Of these, 16 from each group participated in a growth hormone challenge test and the results for 15 women in each group were analysed.

INTERVENTIONS

On the fourth day postpartum women participating in the hormone challenge test were given a subcutaneous injection of a small dose (0.005 mg/kg) of the dopamine agonist apomorphine.

MAIN OUTCOME MEASURES

Growth hormone secretion in response to apomorphine as an index of the functional state of hypothalamic dopamine receptors.

RESULTS

Eight of the 15 women at risk of psychosis subsequently had a recurrence of illness (five bipolar, one schizomanic, and two major depressive illnesses); these women had significantly greater growth hormone responses to apomorphine than the seven at risk women who remained well and the 15 controls, and there were no significant differences between groups in average baseline growth hormone concentrations. The mean (SD) concentrations for women with recurrence, women at risk who remained well, and control women respectively were: average baseline concentrations 1.06 (1.14), 1.44 (1.39), and 0.90 (1.34) mU/l; peak increase in concentrations 13.68 (12.95), 3.46 (4.68), and 3.40 (3.83) mU/l (between group difference p less than 0.05); average increase in concentrations 6.74 (7.01), 1.78 (3.39), and 1.40 (2.05) mU/l (p less than 0.05).

CONCLUSIONS

The onset of affective psychosis after childbirth was associated with increased sensitivity of dopamine receptors in the hypothalamus and possibly elsewhere in the brain. Such changes may be triggered by the sharp fall in circulating oestrogen concentrations after delivery.

Stereospecificity of the dopamine receptor mediating the growth hormone response to apomorphine in man. Short communication

The stereospecificity of the D-2 receptor mediating the growth hormone (GH) response to apomorphine (Apo) and the D-2 receptor regulating prolactin (PRL) secretion were investigated in 10 normal men by examining the effects of cis-flupenthixol (cis-Fx) and trans-flupenthixol (trans-Fx). cis-Fx (1 mg six hourly times four doses) antagonized the GH response to Apo HCl (0.5 mg sc) and increased basal serum PRL concentrations whereas the trans-isomer showed no effect. These findings (a) provide further evidence that the GH response to Apo is mediated by stimulating dopamine (DA) receptors, and, (b) demonstrate stereospecificity of the DA receptor mediating the GH response to Apo and the DA receptor regulating PRL secretion.

Apomorphine in the evaluation of dopaminergic function in man

1. Apomorphine (Apo), a short acting dopamine (DA) receptor agonist, stimulates growth hormone (GH) secretion, decreases prolactin secretion, induces yawning, penile erections and other physiological effects in man. An effect on behavior, movement disorders and alcoholism has also been described. 2. Apo-mediated responses are used to evaluate DA function in psychiatric and neurological disorders. Many of the studies in schizophrenia using the GH response to Apo as an index of central DA function are difficult to interpret because of failure to control for key variables. 3. The GH response to Apo is a useful system to evaluate the effects of various drugs including peptides which may not cross the blood brain barrier on DA function in man. 4. Apo is a potent sedative. Specific antimanic, antischizophrenic, and anticraving effects in alcoholics have not been convincingly demonstrated. Side effects of Apo and failure to use active placebo make double-blind studies difficult. 5. Apo improves parkinsonian symptoms and certain forms of reflex epilepsy but beneficial effects in other involuntary movement disorders requires further documentation. 6. Apo may be a useful agent to evaluate DA function in impotent patients and predict a therapeutic response to long-acting dopaminergic agents. 7. Impairment of DA function may play a role in diabetic impotence. 8. The development of a simple polygraphic method to monitor the yawning response to Apo may facilitate clinical studies on the basic physiology of yawning in man and the use of the yawning response as a measure of central DA function in schizophrenia and other clinical disorders. 9. The use of Apo with 18F-fluorodeoxyglucose positron emission tomography to examine regional DA function in man opens up a promising area of research. 10. Though long-acting orally active aporphine DA agonists and antagonists have been developed the problem of tolerance may limit their therapeutic potential.

Effects of desipramine and total sleep deprivation on hormonal levels of healthy subjects

Plasma prolactin (PRL) and growth hormone (GH) were serially measured over a 5-hour morning period in healthy subjects who twice received a single oral dose of 100 mg desipramine (DMI). The study was carried out both after a regular night of sleep and after 1 night of total sleep deprivation. Clinical studies have suggested that sleep deprivation could potentiate the therapeutic effects of antidepressants, and there were reports on DMI stimulation of GH. The basal PRL levels decreased after sleep deprivation, but subsequently increased after DMI, whereas the same dose of DMI did not affect PRL in the absence of after DMI, whereas the same dose of DMI did not affect PRL in the absence of sleep deprivation. The GH levels increased substantially (8- to 10-fold) after DMI in both experimental conditions. Sleep deprivation neither changed GH basal levels nor potentiated the DMI-induced GH increase.

CCK-33 antagonizes apomorphine-induced growth hormone secretion and increases basal prolactin levels in man

Cholecystokinin (CCK-33) (225 Ivy Dog Units intravenously) had no effect on basal growth hormone (GH) secretion but antagonized the GH response to the dopamine receptor agonist, apomorphine HCl (0.5 mg sc) (N = 7), and induced a transient increase in basal prolactin (PRL) secretion (N = 8) in normal men. These findings are similar to those described with neuroleptics and are compatible with an inhibitory effect of CCK-33, or fragments, on dopamine function in man, at least in the hypothalamic-pituitary axis. However, an inhibitory effect of CCK-33 on the release of GH and a stress-induced increase in PRL secretion cannot be excluded.

Sleep deprivation decreases ventilatory response to CO2 but not load compensation

Because sleep is known to reduce ventilatory drive, and sleep deprivation is a common accompaniment to ventilatory failure, we tested ventilatory response to carbon dioxide (delta V1/delta PCO2) and response to an inspiratory flow resistive load (change in delta P100/delta PCO2 with load) after both a normal night of sleep and after 24 hours of sleep deprivation in 13 healthy volunteers. Sleep deprivation was associated with a significant decrease in delta V1/delta PCO2 from 2.51 +/- .36 to 2.09 +/- .34 L/min/mm Hg (p less than 0.02). However, load compensation was preserved during sleep deprivation. Since many acutely-ill patients are sleep deprived, an associated reduction of ventilatory drive may play a role in progressive respiratory insufficiency.

Dopamine and depression: a review of recent evidence. III. The effects of antidepressant treatments

This paper reviews the effects of antidepressants on brain dopamine (DA) function in people and animals. Acute antidepressant treatments have no consistent effect on DA. Chronic treatment does not appear to change DA synthesis or turnover, or to affect post-synaptic DA receptors. However, there is considerable evidence of increased DA function following chronic antidepressant treatments; the site of these effects is at present unclear, but appears to be beyond the DA receptors. There is also evidence for decreased sensitivity of pre-synaptic DA autoreceptors, though this effect is less well established.

Effect of sulpiride, an atypical neuroleptic, on apomorphine-induced growth hormone secretion

Sulpiride (100 mg IM), an atypical neuroleptic, which does not block dopamine (DA) receptors that are linked to adenylate cyclase, abolished the growth hormone (GH) response to the DA receptor agonist, apomorphine (Apo) HCl (0.5 mg SC) in seven healthy male subjects. These results suggest that Apo increases GH secretion in man by an effect on DA receptors that are not linked to adenylate cyclase.

Hypothalamic-pituitary dopaminergic function in hepatic failure in man

The growth hormone (GH) response to apomorphine HCl (Apo) (0.75 mg sc), a dopamine (DA) receptor agonist, was assessed in healthy chronic alcoholics without cirrhosis (N = 20) and in patients with alcoholic cirrhosis both with (N = 5) and without (N = 14) hepatic encephalopathy (HE). A significant number of cirrhotic patients with (P less than 0.004) and without (P less than 0.002) HE had an impaired GH response (peak increment less than 5 ng/ml) compared with non-cirrhotic individuals. An impaired GH response was independent of the presence of HE. The magnitude of the GH response was unrelated to plasma oestrone, oestradiol, or progesterone concentrations but was significantly correlated with plasma testosterone levels (P less than 0.01). None of the patients with an abnormally low testosterone concentration showed a normal GH response. None of the subjects with HE showed an arousal response to Apo. These results suggest that DA receptor sensitivity is decreased in liver cirrhosis and that this decrease is related to inadequate circulating levels of testosterone. The occurrence of HE is independent of impaired DA function. The present study only evaluates DA function in the hypothalamic-pituitary axis and therefore may not reflect changes in other regions of brain.

Effect of domperidone on apomorphine-induced growth hormone secretion in normal men

Domperidone, a peripheral dopamine (DA) receptor blocker which poorly crosses the blood-brain barrier and which is inactive towards dopamine-sensitive adenylate cyclase, in a dose (100 micrograms/kg) sufficient to increase serum prolactin levels at least 5-fold, decreased the growth hormone (GH) response to the DA receptor agonist, apomorphine HCI (Apo) (0.5 gm s.c.) in each of six normal men examined. The mean GH increment at 30, 45, 60 and 75 min following Apo injection, the mean individual peak increment and the mean individual GH secretion (ng min) was significantly decreased by domperidone pretreatment (p less than 0.005 -p less than 0.002). These results indicate that in man Apo stimulates GH secretion by an effect on DA receptors which are not linked to adenylate cyclase and which are situated at a locus in the hypothalamic-pituitary axis that lies outside the blood-brain barrier.