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The importance of enhanced glutamatergic neurotransmission in the basal ganglia and related structures has recently been highlighted in the development of Parkinson's disease. The pedunculopontine tegmental nucleus (PPN) is the major origin of excitatory, glutamatergic input to dopaminergic nigrostriatal neurons of which degeneration is well known to cause Parkinson's disease. Based on the concept that an excitatory mechanism mediated by glutamatergic neurotransmission underlies the pathogenesis of neurodegenerative disorders, we made an attempt to test the hypothesis that removal of the glutamatergic input to the nigrostriatal neurons by PPN lesions might prevent 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism in the macaque monkey. The PPN was lesioned unilaterally with microinjection of kainic acid, and, then, MPTP was administered systemically. In these monkeys, the degree of parkinsonian motor signs was behaviourally evaluated, and the histological changes in the dopaminergic nigrostriatal system were analysed by means of tyrosine hydroxylase immunohistochemistry. The present results revealed that nigrostriatal cell loss and parkinsonian motor deficits were largely attenuated in the MPTP-treated monkey group whose PPN had been lesioned, compared with the control, MPTP-treated monkey group with the PPN intact. This clearly indicates that the onset of MPTP neurotoxicity is suppressed or delayed by experimental ablation of the glutamatergic input to the nigrostriatal neurons. Such a protective action of excitatory input ablation against nigrostriatal cell death defines evidence that nigral excitation driven by the PPN may be implicated in the pathophysiology of Parkinson's disease.

Background-The somatosensory evoked blink response (SBR) is a characteristic reflex blink elicited by electrical stimulation of peripheral nerves or other anatomical sites. Methods-139 patients with neurological disorders were examined for presence of the SBR. Although the SBR was not usually elicitable, it was present in a subset of patients with Parkinson's disease and with hemifacial spasm. It was also present in a patient with Guillain-Barre' syndrome before the recovery phase. The latency of the EMG activities responsible for the SBR was significantly shorter than that of the startle blink. Conclusions-The SBR is not a variant of the startle blink, but is a release phenomenon transmitted via the brainstem reticular formation. This response may be clinically relevant in disorders associated with brainstem lesions and abnormal blinking.

Objective: This study aimed to examine the ability of barium-confirmed gastroesophageal reflux and the angle of His assessed using upper gastrointestinal series (UGIS) to predict the presence of reflux esophagitis (RE). Design:A total of 1,628 middle-aged Japanese individuals who underwent a radiographic and endoscopic examination between January 2000 and December 2012 were recruited. Methods: The receiver operating characteristic (ROC) curves and the area under the curves (AUCs) were used for RE diagnosis according to barium reflux, the angle of His, and their combination. The predictive sensitivity, specificity, and the Youden index were calculated according to the combination of the two indices, and the maximum value of the Youden index was considered as the optimal cutoff value for RE diagnosis. Results: ROC analysis was performed to estimate the optimal cutoff values of the Youden index for barium reflux and the angle of His. The AUCs for RE diagnosis according to barium reflux, the angle of His, and their combination were 0.76, 0.64, and 0.80, respectively. The optimal cutoff value was an angle of His of 45-46°with barium reflux. The sensitivity, specificity, and the Youden index were 76.3%, 80.4%, and 0.56, respectively. Conclusion:Our results suggest that barium reflux and the angle of His assessed using UGIS are useful for an early diagnosis of RE.