A solitary cluster of parvalbumin-positive neurons--the PV1 nucleus--has been observed in the lateral hypothalamus of rodents. In the present study, we mapped the efferent connections of the PV1 nucleus using nonspecific antero- and retrograde tracers in rats, and chemoselective, Cre-dependent viral constructs in parvalbumin-Cre mice. In both species, the PV1 nucleus was found to project mainly...

The rostral ventromedial medulla (RVM) modulates nociception through changes in the activity of two classes of neuron, ON- and OFF-cells. The activity of these neurons is regulated, in part, by input from the periaqueductal gray (PAG). The objective of this study was to determine whether PAG-mediated antinociception is associated with excitation of both ON- and OFF-cells in the RVM. Microinject...

Abstract Introduction Narcolepsy type 1 is caused by selective loss of orexinergic neurons, resulting in poor maintenance sleep and wakefulness, emergence cataplexy. Orexinergic neurons innervate many brain regions, specific narcolepsy symptoms likely arise from dysfunction distinct regions. Orexin 2 receptors (OX2R) are expressed nearly all wake- REM sleep-regulatory OX2R agonists improve mous...

Severe hemorrhage lowers arterial pressure by suppressing sympathetic activity. This study tested the hypothesis that the decompensatory phase of hemorrhage is mediated by the ventrolateral periaqueductal gray (vlPAG), a region importantly involved in the autonomic and behavioral responses to stress and trauma. Neuronal activity in the vlPAG was inhibited with either lidocaine or cobalt chlorid...

Rodents display characteristic defense responses to predators that are influenced by predatory imminence. The midbrain periaqueductal gray (PAG) serves an important role controlling these responses. The most influential model states that variations in defensive topography are due to distinct PAG regions: ventrolateral PAG (VLPAG) controls postencounter defense, such as freezing and immobility, ...

Repeated microinjections of morphine into the ventrolateral periaqueductal gray (vPAG) produce tolerance to the antinociceptive effect of morphine [Behav Neurosci 113 (1999) 833]. These results may be a direct effect of morphine on cells within the vPAG or be caused by cues linked to the microinjection procedure (i.e. associative tolerance). The objective of this paper was to determine whether ...

We have shown that the modulatory effect of electroacupuncture (EA) on the blood pressure (BP) response induced by visceral organ stimulation is related to inhibition of cardiovascular neurons in the rostral ventrolateral medulla (rVLM) through a mechanism that involves opioids. This effect is long lasting and may involve a long-loop neural supraspinal pathway, including the arcuate nucleus (AR...