To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Hypocretins (Hcrts) are two secreted neuropeptides, hypocretin-1 and hypocretin-2 that are cleaved from a prepropetide precursor. The locus coeruleus (LC) is adjacent to the fourth ventricle in the brainstem and contains neurons that synthetize the monoamine norepinephrine. Interestingly, physical lesions of the LC do not elicit consistent changes in cortical EEG or behavioral indices of arousal. Optogenetics is a technology in which a genetically encoded neuromodulatory actuator(s) is expressed in a targeted cell type of interest and activated by a specific wavelength of light. Optogenetics has allowed us to make major advances in our understanding of the Hcrt and LC systems, and this technology is applied to dissect other arousal systems as well. The ability to target and selectively manipulate Hcrt and LC neurons allows us the opportunity to study these nuclei in different contexts including rodent models of food intake, addiction, stress, attention, and male sexual arousal.
The importance of peptide transmitters in the modulation of sleep and wakefulness has become apparent in recent years. Previous work had focused on the role of monoamines in the circuitry that regulates the transitions between states of vigilance. Histaminergic neurons in the tuberomammillary nucleus are known to be key players in the activation of subcortical afferents during wakefulness (Wada et al., 1991). Activity of noradrenergic neurons in the locus coeruleus correlates with the state of vigilance (Jones, 1991). The role of serotonergic neurons in rapid eye movement (REM) sleep has also been established (Lydic et al., 1987; Monti & Jantos, 1992; Fabre et al., 2000).
In spite of major advances in our understanding of the neuronal circuits that govern the sleep–wakefulness cycle (Pace-Schott & Hobson, 2002), the cell groups involved in the coordination of the different stages of sleep and in the control of the boundaries between sleep states are poorly understood. The development of molecular markers that define neuronal cell groups with distinct physiological properties is expected to enhance our understanding of the regulation of the states of vigilance.
With this in mind, the search for molecular markers that define populations of neurons in areas important for arousal is clearly warranted.
Email your librarian or administrator to recommend adding this to your organisation's collection.