Response Properties of Nucleus Reticularis Lateralis Neurons After Electroacupuncture Stimulation in Rats

A descending inhibitory mechanism from the periaqueductal gray (PAG) to the spinal cord through the nucleus raphe magnus (NRM) is strongly involved in endogenous analgesic system produced by acupuncture stimulation. In addition to the PAG to NRM system which descends in the medial pathway of the brain stem, the nucleus reticularis lateralis (NRL) situated in the lateral part of the brain stem is reported to play an important role in modulating centrifugal antinociceptive action. In the present study, to clarify the role of NRL in acupuncture analgesia, we investigated the response properties of NRL neurons to acupuncture stimulation. The majority of NRM-projecting NRL neurons were inhibited by electroacupuncture stimulation. This effect was antagonized by ionophoretic application of naloxone, indicating that endogenous opioids act directly onto these NRL neurons. By contrast, about half of spinal projecting NRL neurons were excited by electroacupuncture stimulation, suggesting that part of the NRL neurons may modulate pain transmission directly at the spinal level

Measuring biting behavior induced by acute stress in the rat.

Previous reports have indicated that biting behavior is enhanced in rats that are subject to acute stress. Several methods have been proposed for studying this phenomenon, one of which is the electromyography (EMG) of the jaw muscles. In this study, we compared total EMG activity with the EMG activity related to biting behavior, as determined by video monitoring, before and after restraint stress. Wistar albino rats (150 g) were subject to surgery for electrode placement 48 h before measurements. The EMG activity of the masseter muscle on one side was recorded for 10 min before and immediately after 30 min of restraint stress. Restraint stress increased jaw muscle EMG activity, although some of the activity was related to behaviors other than biting. Recording the EMG activity of jaw muscles is useful for measuring the stress response in rats, but careful video monitoring is needed if biting behavior is to be studied in particular

Data for: Analysis of respiratory movements in a mouse model of late Parkinson's disease submitted to stress

Parkinson mous

Data for: Analysis of respiratory movements in a mouse model of late Parkinson's disease submitted to stress

Mendeley librar

Possible effects of periodontal inputs on the masticatory function

This study tested the hypothesis of whether the lack of tooth eruption would affect the masticatory function. For this purpose, we recorded the jaw movement trajectory in the three dimensions and electromyographic (EMG) activity of MAS and DIG muscles in freely behaving osteopetrotic (op/op) and normal mice. A masticatory sequence was divided into food intake and mastication periods, and 10 cycles in the latter stage were selected for analysis. Mean values of total cycle duration, closing phase duration and opening phase duration were obtained from the jaw movement and those of onset time, time duration and amplitude were obtained from the EMGs of the MAS and DIG muscles. The protruding phase coincided with the power stroke lacked in the op/op mouse. The total cycle duration and opening phase duration were longer in the op/op mouse than normal mouse. The pattern of MAS muscle activity in op/op mice was similar to that in normal mice while the duration of the DIG muscle was longer in op/op mice than normal mice. Our results indicate that the periodontal receptors play an important role in the completion of masticatory function