We used functional MRI and a longitudinal design to investigate the brain mechanisms in a previously reported estrogen-dependent visceral hypersensitivity model. We hypothesized that noxious visceral stimulation would be associated with activation of the insula, anterior cingulate cortex, and amygdala, and that estrogen-dependent, stress-induced visceral hypersensitivity would both enhance acti...

Single-unit recording and retrograde tracing techniques were used to assess the receptive field properties, topography, and projections of rat trigeminal primary afferent neurons subsequent to transection of the infraorbital (IO) nerve in adulthood. Four hundred and fifty-eight units were recorded in the trigeminal ganglion ipsilateral to nerve section. Of these, 66.6% had IO receptive fields. ...

Recordings were made from single SI cortical neurons in the anesthetized macaque monkey. Each isolated cortical neuron was tested for responses to a standard series of mechanical stimuli. The stimuli included brushing the skin, pressure, and pinch. The majority of cortical neurons responded with the greatest discharge frequency to brushing the receptive field, but neurons were found in areas 3b...

We characterized response properties of neurons in the caudal ventrolateral medulla (CVLM), a structure involved in pain modulation. Electrophysiological recordings were performed in pentobarbitone-anesthetized control and monoarthritic rats. Noxious pinch, heat, cold and colorectal distension were used for peripheral test stimulation. To study central modulation of CVLM neurons and role in med...

The Kölliker-Fuse nucleus (KF) in the dorsolateral pons has been shown to be the major source of catecholamine innervation of the spinal cord. This has important implications in terms of pain control mechanisms, since catecholamine-mediated mechanisms are essential for the expression of opiate and other varieties of antinociception. This study examines the effects of KF stimulation on responses...

Overuse of medications used to treat migraine headache can produce a chronic daily headache, termed medication overuse headache (MOH). Although "overuse" of opioids, triptans, and over-the-counter analgesics can all produce MOH, the neuronal mechanisms remain unknown. Headache pain is likely to be produced by stimulation of primary afferent neurons that innervate the intracranial vasculature an...

• First, he systematically identified methyleneblue-stained rod-shaped bacteria in tuberculous lesions from diseased organs of men and animals, ruling out the hypothesis that different forms of the disease might be caused by different agents. • Second, he carefully prepared pure cultures of the bacillus, separating them from any other noxious agent that might have been present in the diseased t...

Neurons in the medullary raphe magnus (RM) that are important in the descending modulation of nociceptive transmission are classified by their response to noxious tail heat as ON, OFF, or NEUTRAL cells. Experiments in anesthetized animals demonstrate that RM ON cells facilitate and OFF cells inhibit nociceptive transmission. Yet little is known of the physiology of these cells in the unanesthet...