The brainstem tegmental pedunculopontine nucleus (TPP) is involved in reward signalling and is functionally and anatomically linked to the VTA. We examined the possible role of the TPP as a reward transmission output for GABAA receptors in the VTA in rats not previously exposed to opiates vs. rats that were chronically exposed to and in withdrawal from opiates or in rats that had recovered from...

Nicotine, the primary psychoactive component of tobacco smoke, is known to possess potent rewarding and aversive stimulus properties. The mammalian ventral tegmental area (VTA) is involved importantly in the mediation of the motivational effects of nicotine. However, the neural outputs from the VTA that may be involved in the transmission of the rewarding and aversive motivational effects of ni...

Kamen G. Usunoff 1,2,4, Dimitar E. Itzev2, Stephan R. Lolov3, and Andreas Wree4                                        ...

Microinjections of the cholinergic agonist carbachol into a caudal part of the pontine reticular formation of the rat induce a rapid eye movement sleep-like state. This carbachol-sensitive region of the pontine reticular formation is innervated by cholinergic neurons in the pedunculopontine and laterodorsol tegmental nuclei. The same population of cholinergic neurons also project heavily to the...

Gait freezing and postural instability are disabling features of Parkinsonian disorders, treatable with pedunculopontine nucleus stimulation. Both features are considered deficits of proximal and axial musculature, innervated predominantly by reticulospinal pathways and tend to manifest when gait and posture require adjustment. Adjustments to gait and posture are amenable to pre-preparation and...

Carbachol enhances rapid eye movement (REM) sleep when microinjected into the pontine reticular formation of the cat and rat. Carbachol elicits this REM sleep-like state via activation of postsynaptic muscarinic cholinergic receptors (mAChRs). The present study used in vitro autoradiography of carbachol-stimulated [35S]guanylyl-5'-O-(gamma-thio)-triphosphate ([35S]GTPgammaS) binding to test the...

The basal ganglia are more highly interconnected with the pedunculopontine tegmental nucleus (PPN) than with any other brain region. Regulation and relay of basal ganglia activity are two key functions of the PPN. The PPN provides an interface for the basal ganglia to influence sleep and waking, and the two structures are similarly implicated in learning, reward and other cognitive functions. P...