Sleep is needed for the body to repair and replenish damaged cells due to stress and ultraviolet rays, to trigger hormones that regulate mood, energy and mental acuity, and for the mind to restore alertness and memory. Adequate sleep is also necessary for the immune system to fight infections, support sugar metabolism, perform productively at work or school and maintain healthy relationships. Good sleep is not a luxury, although it has often become so in our 24/7 lifestyles; rather, it is an essential requirement for well-being, optimal functioning, and quality of life. There are several areas of the brain that interact with each other to produce the states of arousal…Although it is likely that other sleep-promoting neurons participate in the induction and maintenance of sleep, the VLPO neurons appear to play a particularly important role in this process. Located in the anterior hypothalamus, the VLPO consists of a dense cluster of sleep-active, galanin-positive neurons surrounded medially and dorsally by a more diffuse extension from the nucleus. (Sherin et al. 1996) …show more content…
(Szymusiak et al. 1998) Sleep recording in animals with cell-specific lesions of the VLPO not only showed a decrease in NREM, REM, and total sleep by up to 50% (Lu et al. 2000), but also demonstrated more frequent transitions between sleep and wake due to reduced stability in both (Lu et al. 2000). Prominent loss of sleep and increase in sleep fragmentation, which lasts for months after VLPO lesions (Lu et al. 2000), suggests that the VLPO neurons represent a central and irreplaceable component of the sleep-promoting
Research into narcoleptic dogs has shown that there is a genetic link in dogs, however, it has also shown that cataplexy occurred during vigorous play or when excited. Moreover, it was found that when the medial medulla is stimulated with an electrode muscle tone disappears. This effect appears to occur to prevent muscle movement during REM sleep and some muscle tone regulation while awake. Siegel found that during a cataplectic episode in the narcoleptic dogs this region of the brain became active. Additionally, it was found that in normal individuals this region of the brain is only highly active during REM sleep. A research in Siegel’s laboratory, Elizabeth Schenkel, demonstrated that normal animals with damaged medial medullas moved during REM sleep. Furthermore, other researchers showed that animals with damage higher on the brain stem, which connected to the medulla “raised their heads, walked and appeared to attack imaginary adversaries during REM sleep” (78).
Humans have a natural rhythm of 25 hours of sleep and wakefulness, in order to reset this the brain plays an important role with the suprachiasmatic nucleus which is a cluster of neurons in the medial hypothalamus of the brain. The SCN
They discovered that, in the brains of the AGS during hibernation, there were shrunken neurons and fewer dendrites (see Figure 3) compared to the aroused and awake squirrels. It was also found that the dendrites had fewer dendritic spines which would result in a decreased number of synapses and neural connections. In stark contrast, when examining the brain of an AGS in the arousal period, there was a dense overlapping of dendrites. The AGS brains had regained all synapses lost during hibernation and had even more neural links than the active squirrels (Dave et al., 2012). However, on returning back into hibernation, these newly gained neural connections wither away. From this research, it is believed that these intermittent arousal phases are vital to the AGS
The VLPO , also known as the “sleep switch” , as well as the anterior thalamus and basal forebrain are activated, which inhibits the arousal system. Particularly, the VLPO, GABA and galanin containing neurons, inhibit and project wake-promoting regions of the ascending reticular system and descending brainstem arousal neurons.
Only one thalamic channel was used for this analysis because the thalamic signals were highly correlated each other: A principle component analysis showed that the first principle component (PC) explained at least 90% of the variance of all thalamic signals for all but one mouse. In the mice whose thalamic signals were explained by their first PCs, a channel was selected as a representative one when it had the heaviest weight of the PC. In the outlier mouse, the electrode was inserted across two different thalamic nuclei, resulting in that first and second PCs were needed to explain the signal variance. Thus, the representative channel for this mouse was selected as the one with the heaviest weight of the PC corresponding to VM nucleus. The spectral density matrix for REM sleep was obtained by using all epochs in REM sleep, while it was estimated for the wake or NREM sleep with the same number of randomly selected epochs as the number of REM epochs. For the inspection of the temporal dynamics of GC, all epochs were decomposed into sets of 25 consequent epochs (100 seconds data) from which time-resolved spectral density matrices were obtained. Note that because the power line artifact was detected around 50Hz, all GC estimation was conducted without the frequency
The function of sleep is to promote restoration. The human body accumulates damages due to impact strain and from reactive oxygen species that damage cells and buildup during times of activity (Sleep-wake cycle, 2006). During sleep, most of the body's systems are in an anabolic state, helping to restore the immune, nervous, skeletal, and muscular systems (Sleep-wake cycle, 2006). Most of the body has restorative processes that can supplement the restorative processes that happen during sleep for long periods of time, but the brain is more reliant on regular intervals of sleep for restoration as quiescent restoration is insufficient (Sleep-wake cycle, 2006). When the body does not get enough sleep, most body functions work at diminished capacity. (Brain Basics, 2017). Sleep deprivation is defined as obtaining inadequate sleep to support adequate daytime alertness (Kryger, Roth, & Dement, 2005). The pathological effects of sleep deprivation can lead to undesirable physiologic
normal counterparts. These findings have led to a robust exploration in the science of sleep
Sleep is considered to be one of the most important processes that living organisms do, but there is a lot that remains unknown about its true function in the brain. The Wen-Bio Gan Group conducted a study on the effects of sleep and dendritic spine formation after motor learning.
The article failed to explain that the epithalamus is a region within the diencephalon. Which location is superior/posterior to the thalamus. The epithalamus consists of several structures which include the pineal gland and secretes melatonin. For instance, the article should have included that the secretes melatonin influences sleep/wake cycles. Why? Because this where the inhibiting activity of each cycle happens. Another example the article claims that if awake signals do not slow down at night you will stay awake. Arguably according to the journal of psychiatry and neuroscience (1994), staying awake or being in a sleeping state depends on the inhibit activity each area is promoting not necessarily be the “slowdown of signals”. For example is the alerting areas of the brain are most active at the time being, they will inhibit activity another area of the brain which has the function for promoting sleep then that inhibition of sleep neurotransmitters will result in a stable wakefulness state. For this reason, I believe this article contains misleading information as it claims to rely on a strong scientific base. It is important to relate with simple terms but educates with
Moreover, many of the claims the article makes, as outlined above, have a biological and psychological scientific basis; however, the article fails to mention the sources from which its conclusions was drawn from. That said, in this paper three differing journal articles will be presented that focus on the different processes that take place during sleep. The scientific journal articles will be analyzed and compared to the Cosmopolitan article. as summarized above.
Users of these treatments still experience stage 1, 2, 3, 4, and REM sleep in the same manner and for the appropriate amounts of time. Brain patterns remained the same in each stage with alpha waves in stage 1, sleep spindles and K-complexes in stage 2, slow-wave brain patterns in stages 3 and 4, and theta waves in REM sleep. The process of gaining wakefulness also remains generally identical. As peak levels of melatonin are reached, the function of MT1 receptors and the body’s need for sleep declines. The suprachiasmatic nucleus becomes more excitatory and begins transmitting signals of
It does so by helping us transition from being awake, to being asleep. This is a result of “neurons in a part of the hypothalamus called the ventrolateral preoptic nucleus (VLPO) connect directly to the many arousal-promoting centers. Rather than stimulating activity in these areas, signals from VLPO neurons inhibit their activity. By shutting down the arousal centers, the VLPO promotes sleep,” (Division of Sleep Medicine at Harvard Medical School in partnership with WGBH Educational Foundation, 2009).
did a study on narcolepsy, described as a poor control of sleep-wake cycle, and found that there is a positive correlation with REM disruptions. They also found that narcoleptic patients have a 90% possibility of destroying neurons in the hypothalamus. The hypothalamus is the region of the brain which is part of the sleep-wake cycle. It is connected to the hippocampus through the thalamus, and part of the limbic system (http://www.ninds.nih.gov, 2014). The limbic system is involved with the emotions of everyday life (Mallick, B. 2011). Mallick also found that during REM sleep “P-wave generator” is activated. This is where neurons branch out towards the thalamus, and visual pathway. They found that this generator facilitates hippocampal
Biologists, Psychologists and Therapists have been trying to inaugurate a treatment for insomnia which has a negative effect on sleep. Deep sleep aids a “major biological restorative function” as it renews our physical energy. The issue is that insomniacs don’t sleep enough and that means they lack physical energy. (2)
All forms of life have their distinct predictable daily schedules known as the circadian rhythm. This endogenous twenty-four hour rhythm controls the metabolic, behavioral, and biological functions of an organism’s system. In mammals, the circadian clock is located in the suprachiasmatic nucleus (SCN) which is a group of cells positioned on the anterior hypothalamus in the brain. A disruption in the circadian rhythms sleep/wake cycle disrupts the timing and pattern of sleep in mice and thus, alters the quality of sleep overall [1]. The quality of sleep has often been determined by the frequency of rapid eye movement (REM) sleep present in the sleep cycle, the more frequent meaning a higher quality of sleep.