Neurons, Afferent

Cerebellar granule cells isolated from postnatal day 7 rat pups are ideal for studying epigenetic events associated with the regulation of neuronal gene expression. These cultures contain from 90 to 95% glutamatergic granule cells and express mRNAs encoding a variety of ionotropic and metabotropic glutamate receptors as well as virtually all of the GABAA-receptor subunit mRNAs to different extents. A unique feature of this culture system is that the neurons undergo time-dependent maturation changes in vitro that mimic many of the characteristics of these receptors occurring in vivo.

It is well accepted that pain is a multidimensional experience, but little is known of how the brain represents these dimensions. We used positron emission tomography (PET) to indirectly measure pain-evoked cerebral activity before and after hypnotic suggestions were given to modulate the perceived intensity of a painful stimulus. These techniques were similar to those of a previous study in which we gave suggestions to modulate the perceived unpleasantness of a noxious stimulus.

Multiunit activity was recorded in left and right sensorimotor cortex of rabbits in the state of tonic immobility. After the first immobilization session, the discharge frequency changed in 47% cells in the right hemisphere: 30% decreased their frequency, and 17% increased. In the left hemisphere, only 18% cells changed their discharge frequency (13% decreased and 5% increased). Reciprocal changes in discharge frequency could be observed in the neighboring neurons (recorded by the same electrode).

BACKGROUND CONTEXT: Spinal manipulation (SM) is a form of manual therapy used clinically to treat patients with low back and neck pain. The most common form of this maneuver is characterized as a high-velocity (duration <150 ms), low-amplitude (segmental translation <2 mm, rotation <4 degrees , and applied force 220-889 N) impulse thrust (high-velocity, low-amplitude spinal manipulation [HVLA-SM]).

Muscle spindles contribute to sensorimotor control by supplying feedback regarding muscle length and consequently information about joint position. While substantial study has been devoted to determining the position sensitivity of spindles in limb muscles, there appears to be no data on their sensitivity in the low back. We determined the relationship between lumbar paraspinal muscle spindle discharge and paraspinal muscle lengthening estimated from controlled cranialward movement of the L(6) vertebra in anesthetized cats.

Increasing our knowledge regarding intrafusal fiber distribution and physiology of paraspinal proprioceptors may provide key insights regarding proprioceptive deficits in trunk control associated with low back pain and lead to more effective clinical intervention. The use of vertebral movement as a means to reliably stretch paraspinal muscles would greatly facilitate physiological study of paraspinal muscle proprioceptors where muscle tendon isolation is either very difficult or impossible.

In traditional folk medicine, Xanthoxylum plants are referred to as 'toothache trees' because their anesthetic or counter-irritant properties render them useful in the treatment of pain. Psychophysical studies have identified hydroxy-alpha-sanshool as the compound most responsible for the unique tingling and buzzing sensations produced by Szechuan peppercorns or other Xanthoxylum preparations. Although it is generally agreed that sanshool elicits its effects by activating somatosensory neurons, the underlying cellular and molecular mechanisms remain a matter of debate.

Resveratrol is a polyphenol produced by plants that has multiple beneficial activities similar to those associated with caloric restriction (CR), such as increased life span and delay in the onset of diseases associated with aging. CR improves neuronal health, and the global beneficial effects of CR have been postulated to be mediated by the nervous system. One key enzyme thought to be activated during CR is the AMP-activated kinase (AMPK), a sensor of cellular energy levels.

Afferent signals from the stomach play an important role in inhibition of food intake during a meal. The gastric hormone ghrelin can influence gastric satiety signalling by altering the sensitivity of gastric vagal afferents. Changes in diet, including food restriction and high fat diet (HFD) alter satiety signalling. We hypothesised that the function of gastric vagal afferent endings are affected by both a period of food restriction and a high fat diet, and that the inhibitory effect of ghrelin on vagal afferents is influenced by the different feeding conditions.

A brief review of traction and its application as a therapeutic tool is outlined. The preliminary results obtained indicate that traction, as used in this study, along with isokinetic exercises and chiropractic manipulation, have a very positive effect on tension headaches originating from the posterior muscles in conjunction with pathomechanics of the cervical spine.