By W. Dargoth. Dowling College.
Shift Chapter 130: Sleep Loss and Sleepiness 1899 workers are also at an increased risk for injury and accidents Sleep Deprivation: Experimentally (51) purchase 40 mg levitra super active otc. Three Mile Island generic 20 mg levitra super active amex, Exxon Valdez 20 mg levitra super active mastercard, and the Space Shut Induced tle Challenger represent disasters where fatigue among Sleep loss results in compromised neurobehavioral perfor nighttime workers has been implicated cheap levitra super active 40 mg free shipping. Various per Both intrinsic biological and environmental factors con formance assessments probe the functional capability of the tribute to the problem sleepiness of shift workers. Shift workers exist measures of sleepiness and neurobehavioral problems. Psy in states of chronic sleep debt because of insufficient sleep chomotor vigilance and probed memory impairment as well during each 24-hour period. Human entrainment to the as somatic complaints appear to increase during acute total natural 24-hour light/dark cycle establishes a fixed neuro and repeated partial sleep deprivation (62–65). Some stud biologic propensity to be active, alert, and performing dur ies have been unable to show cognitive impairment during ing the daylight hours, and to sleep during the nocturne sleep deprivation (66), leading to speculation that chronic (58). Shift work requires maximum psychomotor and cog partial sleep deprivation does not result in cumulative de- nitive performance at night, that time when virtually all creases in performance (67,68). A number of factors may zeitgebers are cueing the endogenous circadian pacemaker have contributed to the disparate outcomes among studies to reduce arousal, activity, and sleep. Thus, not only must of waking performance after chronic sleep restriction. Many shift workers compensate for societal disruptions to their of the negative studies were limited by the fact that the sleep, such as noise and pressures to socialize and perform primary outcome measures were performance assessments domestic chores, but they must also overcome daylight and with robust practice effects (62). Learning curves confound darkness time cues to work and sleep, respectively (53). In other words, repeated testing on a Jet Lag measure with a learning curve will lead to improved perfor Jet lag is a condition following transmeridian travel that mance scores. Thus, if cumulative sleep loss does impair involves a myriad of problems. Symptoms include daytime performance on this measure, the decrement will be masked sleepiness and fatigue, impaired daytime cognitive perfor by the learning-derived improvement. Performance vigi dark cycle increases with the number of time zones crossed. Stud lag are mediated by disruptions of the sleep and circadian ies utilizing such measures show increased lapses and height systems. Both the homeostatic mechanism for sleep (sleep ened variability of performance during sustained vigilance drive that increases as duration of wakefulness increases) tasks (62), all of which show deterioration after acute, total and circadian neurobiology interact to determine neurobe sleep deprivation, and after chronic partial sleep depriva havioral alertness and performance (59). Reduction in speed of response, although not a hour light/dark cycle, although sleep loss incurred by travel function of lapses or failure to respond, appear attributable can also serve to exacerbate the condition. The endogenous to a decline in the ability to continuously allocate attention circadian pacemaker does not immediately adapt to the new to the task and to respond motorically as rapidly as possible. Sleepiness, fatigue, stress, and impaired 1900 Neuropsychopharmacology: The Fifth Generation of Progress vigilance during sustained sleep restriction accumulate over therapy alone, pharmacotherapy alone, and the two in com time (62). Studies suggest that performance degrades in a bination provide comparable efficacy in the short term, but dose–response manner (69). Kuo found that during chronic behavioral approaches may excel in the long term. Subjects were unaware of their disturbance, and quality of life, remit has not yet clearly neurocognitive dysfunction, because they 'felt fine. Remarkably, the hypothalamic-pituitary-adrenal axis of these compounds in treating insomnia is described in (the 'stress' axis) remains largely unaffected by sleep loss. Typically, the longer- changes can be reversed with recovery sleep. The newer agents, zaleplon and zolpidem, appear little, if any, worsening of mood, anxiety, or anger, but to produce less daytime problems than the older agents (80), does produce worsening self-reports of fatigue, vigor, and however, whether any of these compounds reverse the day- confusion. In contrast, depressed patients demonstrate in- time impairments to which insomniacs are prone remains creased locomotor activity, increased self-ratings of vigor, to be seen. This seemingly para macologic and nonpharmacologic treatments not only for doxic effect in depressed individuals may reflect an underly sleep quality (total sleep time, wake after sleep onset, sleep ing heightened sensitivity to the sleep deprivation-induced efficiency), but also for daytime performance, function, and increases in dopamine, hypothalamic-pituitary-thyroid axis distress.
An international pedigree derived from a homogeneous population in Quebec two-stage genome-wide search for schizophrenia susceptibility points to a locus of major effect on chromosome 12q23-q24 discount 40 mg levitra super active otc. A genome survey pean-American schizophrenia kindreds: results of the NIMH indicates a susceptibility locus for bipolar disorder on chromo- Genetics Initiative and Millennium consortium generic 20mg levitra super active with visa. Detera-Wadleigh SD levitra super active 20mg free shipping, Hsieh W-T levitra super active 20 mg online, Berrettini WH, et al. A schizophrenia netic linkage mapping for a susceptibility locus to bipolar illness: locus may be located in region 10p15-p11. Am J Med Genet Chromosomes 2, 3, 4, 7, 9, 10p, 11p, 22, and Xpter. Detera-Wadleigh SD, Badner JA, Berrettini WH, et al. Evi- analysis of chromosome 21q22 supports prior evidence for a dence for a bipolar susceptibility locus on 13q32 and other putative bipolar affective disorder locus. Am J Hum Genet 1999; potential loci on 1q32 and 18p11. A complete ge- support a possible locus for bipolar disorder in the velocardiofa- nome screen for genes predisposing to severe bipolar disorder cial syndrome region on chromosome 22. Linkage of bipolar affec- of the NIMH genetics initiative bipolar pedigrees: chromosomes tive disorder to chromosome 18 markers in a new pedigree 3,5,15,16,17, and 22. Linkage analysis patients diagnosed with velo-cardio-facial syndrome and their of families with bipolar illness and chromosome 18 markers. Genetic mapping ders in patients diagnoses with VCFS: does a hemizygous dele- using haplotype, association and linkage methods suggests a tion of chromosome 22q11 result in bipolar affective disorder? Significant linkage between VCFS patients with psychiatric disorders. Am J Med Genet 1997; bipolar affective disorder and chromosome 12q24. A locus for bipolar deficiency as cause of the flushing reaction to alcohol in Japa- affective disorder on chromosome 4p. Support for the possible aldehyde dehydrogenase genotypes and alcoholism in Chinese locus on chromosome 4p15 for bipolar affective disorder. Ann Neurol 1993; susceptibility genes in bipolar affective disorder—evidence for 34:752–754. Grigoroiu-Serbanescu M, Martinez M, Nothen MM, et al. Pat- diseases: analysis of SNPs around APOE in Alzheimer disease. On the interpretation of association studies in 100. Hablotype relative risks: an eary reliable Engl J Med 1994;330:962–967. Statistical properties of the haplotype relative risk. The sins of the fathers and mothers: Genomic linkage disequilibrium: the insulin gene region and insulin-de- imprinting in mammalian development. A conditional inference framework for chiatry 1999;56:1019–1031. Anticipation in Swed- tests of linkage and/or association. Am J Hum Genet 1998;63: ish families with bipolar affective disorder. Birth-cohort changes association between bipolar disorder and MAOA gene polymor- in manic and depressive disorders in relatives of bipolar and phisms.
Does tumor necrosis factor play a role in alco- of ethanol on punished responding in the P and NP rats buy levitra super active 20mg otc. The potential pitfalls of a case-controlled Clin Exp Res 1991;15:700–704 buy 20 mg levitra super active. Alcohol and the brain: pharmacological insights for ethanol sensitivity in BXD recombinant inbred mice purchase levitra super active 20 mg without prescription. Biological generic 40mg levitra super active fast delivery, psychological and environmental pre- 31. Ethanol intoxication in dictors of the alcoholism risk: a longitudinal study. J Stud Alcohol Drosophila: genetic and pharmacological evidence for regulation 1998;59:485–494. Selective genotyping studies in human and animal models. Am J Addict 1999;8: for the role of 5-HT2A, 5-HT2C, and GABAA6 receptors and 261–278. Pharmacogenetics of responses to alcohol and genes pilot study. General and specific inheritance of substance abuse search for genes that relate to a low level of response to alcohol. Arch Gen Psychiatry 1998;55: Alcohol Clin Exp Res 2001;25:323–329. An 8-year follow-up of 450sons of sons of alcoholics. The relationships of a family history Alcohol Clin Exp Res 1999;23:1312–1319. The EEG after six domains of life functioning to the development of alcohol alcohol administration in men at risk for alcoholism. EEG, autonomic and subjective tween self-rating of the effects of alcohol and alcohol challenge correlates of the risk for alcoholism. J Stud Alcohol 1993;54: results in ninety-eight young men. Meta-analysis of subjective sensitivity to alcohol in electroencephalogram (EEG) and event-related brain potentials sons of alcoholics. A twin study of genetic in daughters of alcoholics: a pilot study and a comparison with influences on the acute adaptation of the EEG to alcohol. The relationship of hol Clin Exp Res 1999;23:494–501. Identification of a Alcohol Clin Exp Res 2000;24:27A. Ser857-Asn857 substitution in DRK1 (KCNB1), population 20. Alcohol chal- frequencies and lack of association to the low voltage alpha EEG lenges in young men from alcoholic pedigrees and control fami- trait. Children of alcoholics exhibit attenu- brain development. Clinical importance of age to alcohol in sons of alcoholics. Alcohol Clin Exp Res 1991;15: at onset in type 1 and type 2 primary alcoholics. Common genetic to alcohol in young adult Jewish men: a pilot study. J Stud risk factors for conduct disorder and alcohol dependence. Behavioral out- graphic responses to alcohol challenge in Native American Mis- comes among children of alcoholics: during the early and middle sion Indians. Genetic-environ- Chapter 98: Vulnerability Factors for Alcoholism 1409 mental interaction in the genesis of aggressivity and conduct to naloxone in sons of alcohol-dependent men. Int J Neuropsychopharmacol tary adrenal axis functioning and cerebrospinal fluid cortico- 1998;1:153–168. What is inherited in the predisposition ics after recent and long term abstinence.
Indeed quality levitra super active 20 mg, tion buy 40 mg levitra super active, that is purchase levitra super active 20mg on line, to assess the silent order 20mg levitra super active with mastercard, latent period between status agents such as phenobarbital, carbamazepine, and several epilepticus and the first spontaneous limbic seizure. Finally, N-methyl-D-aspartate (NMDA)–receptor antagonists at- these animal models provide opportunities to test innovative tenuate the kindling rate, whereas other commonly used clinical interventions for the treatment and possible cure of antiepileptic compounds, such as phenytoin, do not have MTLE (54,55). This clinically relevant use of the kin- These models of limbic epilepsy have been exploited to dling model will eventually also provide a better definition test novel concepts related to the pathophysiology of of the molecular events that underlie the progressive length- MTLE. For example, hyperexcitable neurons, both projec- ening of seizure activity on repetitive stimulation. In some cases, the synaptically me- diated responses in these neurons show prolonged excitatory Animal Models of MTLE depolarizations with multiple superimposed action poten- The kindling model has been, and continues to be, valuable tials (23,56,57) (Fig. Underlying these profound for our understanding of the role of particular brain regions changes are multiple presynaptic and postsynaptic altera- in the generation and propagation of seizures. However, tions in neurotransmitter receptors and ion channels. Since the 1980s, the development of ani- in both inhibitory and excitatory receptors, namely GABA mal models with recurrent, spontaneous convulsions has and glutamate receptors, contribute to the abnormal physi- therefore become a major focus of epilepsy research. These changes are necessarily complex be- 1848 Neuropsychopharmacology: The Fifth Generation of Progress FIGURE 127. Seizures in human MTLE and in rat models of MTLE: illustrations of altered neu- ronal physiology. Chronic epilepsy in animals was induced by prolonged electrical stimulation or chemoconvulsants (see text). A: Bilateral recordings from hippocampus (LH, RH) and amygdala (LA, RA) in rat (A1) and human (A2). Both sites are involved at the onset, a finding suggesting a synchronizing pulse from an external site. The human recording shows a later but regionally simultaneous onset on the left hemisphere. This time difference is not seen in rats, probablyas a result of stronger interhemispheric connections. B: Intracellular recordings from hippocampal and amygdalar neurons in normal and epileptic rats. C: Intracellular recordings from the entorhinal cortex of epileptic rats, also illustrating the prolonged depolarizations and multiple superimposed action potentials. Overall, this figure emphasizes the changes throughout the limbic system in nonhippocampal regions. In addition, the models also involve simplicity of the new circuit and the easily visualized ana- many other biochemical changes in one or more parts of tomic change (64). Because the animal models of MTLE the limbic seizure network. This ever-increasing list includes show extensive neuronal loss in multiple brain areas, it is ions, enzymes, hormones and their receptors, and a host quite likely that seizure-related synaptic and circuit rear- of other chemical entities. In most instances, however, the rangements also occur in extrahippocampal regions (65). Experimental MTLE also provides an opportunity to CURRENT CONCEPTS OF EPILEPTOGENESIS: evaluate the existence and functional significance of synaptic MOLECULES AND MECHANISMS rearrangements, which occur in response to epileptogenic Neurotransmitters insults or neuronal damage and may be involved in the development of spontaneously recurring seizures (20–24, A long-standing theme in epilepsy research has been the 63). The prototype for this process, the sprouting of mossy role of the major inhibitory neurotransmitter, GABA, in Chapter 127: Temporal Lobe Epilepsy 1849 both epileptogenesis and chronic epilepsy. Defects of the compositions are abnormal in epileptic brain tissue of both GABA system have been implicated since the 1970s, when humans and animals (60,61), although their role in epilep- a loss of GABA neurons was suspected to underlie seizures togenesis is currently unclear. This not only suggests that (66), but physiologic studies in animal models of epilepsy AMPA and kainate receptors are involved in spontaneously did not necessarily reveal a reduction in GABAergic inhibi- recurrent seizure activity but also offers promising new ideas tion (67). Other studies proposed a specific defect in the for antiepileptic drug development (74). This hy- receptors and interference with the function of glutamate pothesis is still rather controversial, attesting to the complex- transporters, a group of several distinct proteins that control ity of GABAergic neurotransmission (63). However, it the extracellular concentration of glutamate in the brain, seems unlikely that a single deficit in the GABAergic systems too, have profound consequences on neuronal excitability.
8 of 10 - Review by W. Dargoth
Votes: 273 votes
Total customer reviews: 273