Pontine reticular formation sleep

Thakkar, M. M Ramesh, V., Cape, E. G. et al. (1999). REM sleep enhancement and behavioral cataplexy following orexin (hypocretin)-II receptor antisense perfusion in the pontine reticular formation. Sleep Res. Online 2, 112-20. 

In fact, there is a good deal of evidence to support this suggestion. First, more than half the neurons in the PPT fire rhythmically only when PGO waves are evident and their firing starts immediately before the PGO waves appear. Second, in cats, REM sleep is augmented by direct injection of either carbachol, or more selective muscarinic agonists, or the anticholinesterase, neostigmine, into the pontine reticular formation (one of the projection sites for PPT). Third, REM sleep is abolished by lesion of the PPT nucleus but, interestingly, not by lesion of the LDT. 

Baghdoyan, H. A. Lydic, R. (1999). M2 muscarinic receptor subtype in the feline medial pontine reticular formation modulates the amount of rapid eye movement sleep. Sleep 22, 835-47. 

Baghdoyan H. A., Monaco, A. P., Rodrigo-Angulo, M. L. et al. (1984a). Microinjection of neostigmine into the pontine reticular formation of cats enhances desynchronized sleep signs. J. Pharmacol. Exp. Then 231, 173-80. 

Semba, K. (1993). Aminergic and cholinergic afferents to REM sleep induction regions of the pontine reticular formation in the rat. J. Comp. Neurol. 330, 543-56. 

Vazquez, J. Baghdoyan, H. A. (2004). GABAA receptors inhibit acetylcholine release in cat pontine reticular formation implications for REM sleep regulation. J. Neurophysiol. 92, 2198-206. 

Bourgin, P., Escourrou, P., Gaultier, C. Adrien, J. (1995). Induction of rapid eye movement sleep by carbachol infusion into the pontine reticular formation in the rat. Neuroreport 6, 532-6. 

The most recent species to be studied with respect to cholinergic REM sleep enhancement is mouse (Lydic et al, 2002). Microinjection of neostigmine into the pontine reticular formation of C57BL/6J (B6) mouse has now been shown to cause a REM sleep-like state (Fig. 5.3). REM sleep also can be enhanced in B6.v-lepob... 

REM sleep (Kodama et al, 1990 Leonard Lydic, 1995, 1997) and cholinergic REM sleep enhancement (Lydic et al., 1991), ACh release is significantly increased in the same regions of the pontine reticular formation where microinjection of cholinomimetics enhances REM sleep (1.3 and 1.4 on Fig. 5.1). These results support the conclusion that at the level of ACh release, the cholinergic enhancement of REM sleep is a faithful model of spontaneous REM sleep. 

ACh regulates the cortical arousal characteristic of both REM sleep and wakefulness (Semba, 1991, 2000 Sarter Bruno, 1997, 2000). Medial regions of the pontine reticular formation (Figs. 5.2 and 5.7) contribute to regulating both the state of REM sleep and the trait of EEG activation. Within the medial pontine reticular formation, presynaptic cholinergic terminals (Fig. 5.1) that release ACh also are endowed with muscarinic cholinergic receptors (Roth et al, 1996). Autoreceptors are defined as presynaptic receptors that bind the neurotransmitter that is released from the presynaptic terminal (Kalsner, 1990). Autoreceptors provide feedback modulation of transmitter release. Autoreceptor activation... 

Coleman, C. G., Baghdoyan, H. A. 8r Lydic, R. (2006). Dialysis delivery of an adenosine A2A agonist into the pontine reticular formation of C57BL/6J mouse increases pontine acetylcholine release and sleep. J. Neurochem. 96, 1750-9. 

Marks, G. A. Birabil, C. G. (1998). Enhancement of rapid eye movement sleep in the rat by cholinergic and adenosinergic agonists infused into the pontine reticular formation. Neuroscience 86, 29-37. 

Velazquez-Moctezuma, J., Shalauta, M. D., Gillin, J. C. 8r Shiromani, P. J. (1990a). Microinjections of nicotine in the medial pontine reticular formation elicits REM sleep. Neurosci Lett. 115, 265-8. 

Many sites within the pons and medulla that contribute to the increased levels of arousal that characterize wakefulness and rapid eye movement (REM) sleep are under glutamatergic control. The pontine reticular formation, for example, is involved in phenomena related to REM sleep and to motor activity during wakefulness. Glutamatergic neurotransmission also mediates the responses of cells of the medial pontine reticular formation. These cells are depolarized and... 

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