Pedunculopontine nucleus

Nicotine is the main psychoactive ingredient of tobacco and is responsible for the stimulant effects and abuse/ addiction that may result form tobacco use. Cigarette smoking rapidly (in about 3 sec ) delivers pulses of nicotine into the bloodstream. Its initial effects are caused by its activation of nicotinic acetylcholine (nACh) receptors. nACh receptors are ligand-gated ion-channels and pre- and postsynaptically located. Reinforcement depends on an intact mesolimbic dopamine system (VTA). nACh receptors on VTA dopamine neurons are normally activated by cholinergic innervation from the laterodorsal tegmental nucleus or the pedunculopontine nucleus. 

Figure 4.2 Model of the network responsible for paradoxical sleep onset and maintenance Abbreviations DRN, dorsal raphe nucleus 5-HT, serotonin LC, locus coeruleus NA, noradrenaline LDT, laterodorsal tegmental nucleus Ach, acetylcholine Me, magnocellular reticular nucleus Gly glycine DPMe, deep mesencephalic reticular nucleus PAG, periaqueductal gray DPGi, dorsal paragigantocellular reticular nucleus PPT, pedunculopontine nucleus PRN, pontine reticular nucleus SLD, sublaterodorsal nucleus Glu, glutamate Pef/HLA perifornical/lateral hypothalamic area Hcrt, hypocretin (i.e. orexin).

Takakusaki, K, Shiroyama, T. Kitai, S. T. (1997). Two types of cholinergic neurons in the rat tegmental pedunculopontine nucleus electrophysiological and morphological characterization. Neuroscience 79, 1089-109. 

Figure 12.1 Extracellular adenosine concentrations in different brain areas, measured with in vivo microdialysis from cats during sleep deprivation (6 h gentle handling) and recovery sleep. Concentrations are given as a percentage of pre-deprivation values. BF, basal forebrain CX, cingulate cortex TH, VA/VL nucleus of thalamus POA, preoptic hypothalamic area DRN, dorsal raphe nucleus PPT, pedunculopontine nucleus. In BF and CX adenosine rises during sleep deprivation, but starts to decline during deprivation in CX, whereas the decline occurs during recovery in the BF. In other areas there is no accumulation during sleep deprivation. Modified from Porkka-Heiskanen et al. (2000).

Laviolette, S.R., Alexson, T.O., van der Kooy, D. Lesions of the tegmental pedunculopontine nucleus block the rewarding effects and reveal the aversive effects of nicotine in the ventral tegmental area. J. Neurosci. 22 8653, 2002. 

Jenkinson, N., Nandi, D., Miall, R.C., Stein, J.F., and Aziz, T.Z., Pedunculopontine nucleus stimulation improves akinesia in a Parkinsonian Monkey, Neuroreport, 15, 2621-2624, 2004. Furth, J. and Kahn, M.C., Transmission of leukemia of mice with a single cell, Am.. Cancer, 31, 276-282, 1937. 

Homma Y, Skinner RD, Garcia-Rill E. Effects of pedunculopontine nucleus (PPN) stimulation on caudal pontine reticular formation (PnC) neurons in vitro. J Neurophysiol 2002 87 3033-3047. 

Other structures have recently been stimulated including the motor cortex [52], the pedunculopontine nucleus in the brain stem [54] and the zona incerta (a structure adjacent to the STN) [55]. This indicates that the stimulation of various structures along the motor loop can lead to improvement of parkinsonian signs but spreading to other adjacent structures cannot be excluded. In the present chapter we focus on DBS of the STN. 

Mamiya N, Buchanan R, Wallace T, Skinner RD, Garcia-Rill E. 2005. Nicotine suppresses the P13 auditory evoked potential by acting on the pedunculopontine nucleus in the rat. Exp Brain Res 164 109-119. 

Lavoie B, Parent A (1994) Pedunculopontine nucleus in the squirrel monkey cholinergic and glutamatergic projections to the substantia nigra. J Comp Neurol 344, 232-241. 

Mazzone P, Lozano A, Stanzione P, Galati S, Scamati E, Peppe A, Stefani A (2005, Nov 28) Implantation of human pedunculopontine nucleus a safe and clinically relevant target in Parkinson s disease. Neuroreport 16(17) 1877-1881 Mohler H (2007) Molecular regulation of cognitive functions and developmental plasticity impact of GABAA receptors. J Neurochem 102(1) 1-12... 

Output targets of the substantia nigra include the following the thalamus, superior colliculus and the pedunculopontine nucleus (Beckstead 1979 Deniau and Chevalier 1992 Gerfen et al. 1982 Kita and Kitai 1987 Nakanishi et al. 1987b). Nigral inputs to the thalamus are directed to two main parts of the thalamus. The first are the set of nuclei, including the intralaminar nuclei, which project back to the striatum. The second... 

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