Previous physiological investigations have suggested the existence of a neural circuit that coordinates activation of motor and autonomic efferents before or at the onset of exercise. Traditionally these circuits have been postulated to involve forebrain areas. However, overlapping populations of medullary reticular formation neurons that participate in motor or autonomic control have been desc...

The anatomical substrate and behavioral pharmacology of stimulation-produced analgesia resulting from electrical stimulation of the pontomesencephalic nucleus cuneiformis (NCF) was determined in the present study. Maximum increase in nociceptive tail-flick latencies following NCF stimulation occurred during the first 5 min post stimulation and decreased afterwards. The increased reflex latency ...

Selective retrograde labelling was used as an autoradiographic method to identify possible excitatory amino acid afferents to nucleus raphe magnus (NRM). Injections of 25-50 nl 10(-2) or 10(-3) M D-[3H]aspartate into the NRM resulted in prominent labelling of cells in ventrolateral mesencephalic periaqueductal gray (PAG). Electrophysiologically, stimulation in ventrolateral PAG excited cells in...

Serotonin is thought to contribute to the syncopal-like response that develops during severe blood loss by inhibiting presympathetic neurons of the rostroventrolateral medulla (RVLM). Here, we tested whether serotonin cells activated during hypotensive hemorrhage, i.e., express the protein product of the immediate early gene c-Fos, are critical for the normal sympathetic response to blood loss ...

To examine if brain neurons involved in the efferent control of the kidneys possess melanocortin-4 receptor (MC4-R) and/or tryptophan hydroxylase (TPH). Retrograde tracing pseudorabies virus (PRV)-614 was injected into the kidneys in adult male MC4R-green fluorescent protein (GFP) transgenic mice. After a survival time of 3-7 days, spinal cord and brain were removed and sectioned, and processed...

Migraine is one of the commonest neurological disorders. Despite intensive research, its exact pathomechanism is still not fully understood and effective therapy is not always available. One of the key molecules involved in migraine is glutamate, whose receptors are found on the first-, second- and third-order trigeminal neurones and are also present in the migraine generators, including the do...

A wealth of pharmacological and behavioral data suggests that spinally projecting serotonergic cells mediate opioid analgesia. A population of medullary neurons, located within raphe magnus (RM) and the neighboring reticular nuclei, contains serotonin and is the source of serotonin in the spinal dorsal horn. To test whether serotonergic neurons mediate opioid analgesia, morphine was administere...

AIM To examine the role of cholinergic neurons in the nucleus raphe magnus (NRM) in noxious heat stimulation and in the effects of morphine-induced antinociception by rats. METHODS After the cholinergic neuron selective toxin, AF64A, was microinjected into the NRM, we examined changes in the antinociceptive threshold and effects of morphine (5 mg/kg, ip) using the hot-plate (HP) and tail-flic...

The present study investigated the role of calcitonin gene-related peptide (CGRP) on nociception in nucleus raphe magnus (NRM) and the interaction between CGRP and opioid peptides in NRM of rats. CGRP-like immunoreactivity was found at a concentration of 6.0+/-0. 77 pmol/g in NRM tissue of ten samples of rats, suggesting that it may contribute to physiological responses orchestrated by the NRM....