Pain and masochistic behaviour: The role of descending modulation.

Background: The mechanisms of pain perception in individuals with masochistic behaviour (MB) remain poorly documented. We hypothesized that MB is associated with context-specific changes in descending pain modulation.

Methods: We compared the effects of four standardized sets of images with positive (erotic), negative (mutilations), masochistic or neutral emotional valences on the RIII nociceptive reflex evoked by electrical stimulation of the sural nerve and recorded on the ipsilateral biceps femoris in 15 controls and 15 men routinely engaging in MB.

Repetitive transcranial magnetic stimulation for neuropathic pain: a randomized multicentre sham-controlled trial.

Repetitive transcranial magnetic stimulation (rTMS) has been proposed to treat neuropathic pain but the quality of evidence remains low. We aimed to assess the efficacy and safety of neuronavigated rTMS to the primary motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC) in neuropathic pain over 25 weeks. We carried out a randomized double-blind, placebo-controlled trial at four outpatient clinics in France.

Hyperalgesia induced by low-dose opioid treatment before orthopaedic surgery: An observational case-control study.

Background: Chronic pain and opioid consumption may trigger diffuse hyperalgesia, but their relative contributions to pain vulnerability remain unclear.

Objectives: To assess preoperative opioid-induced hyperalgesia and its postoperative clinical consequences in patients with chronic pain scheduled for orthopaedic surgery.

Design: A prospective observational study.

Prolonged continuous theta-burst stimulation is more analgesic than 'classical' high frequency repetitive transcranial magnetic stimulation.

Background: Repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (M1) at high frequency (>5 Hz) induces analgesic effects, probably by activating pain modulation systems. A new rTMS paradigm--theta burst stimulation (TBS)--consists of bursts of three pulses at 50 Hz repeated five times per second. Like high frequency rTMS, both intermittent and prolonged continuous TBS (iTBS and pcTBS) lead to a facilitation of cortical excitability.

A new neuronal target for β-amyloid peptide in the rat hippocampus.

In Alzheimer's disease, amyloid beta peptide (Aβ) accumulation is associated with hippocampal network dysfunction. Intrahippocampal injections of Aβ induce aberrant inhibitory septohippocampal (SH) network activity in vivo and impairment of memory processing. In the present study, we observed, after hippocampal Aβ treatment, a selective loss of neurons projecting to the medial septum (MS) and containing calbindin (CB) and/or somatostatin (SOM).

Decreased rhythmic GABAergic septal activity and memory-associated theta oscillations after hippocampal amyloid-beta pathology in the rat.

The memory deficits associated with Alzheimer's disease result to a great extent from hippocampal network dysfunction. The coordination of this network relies on theta (symbol) oscillations generated in the medial septum. Here, we investigated in rats the impact of hippocampal amyloid beta (Abeta) injections on the physiological and cognitive functions that depend on the septohippocampal system.

Firing properties of anatomically identified neurons in the medial septum of anesthetized and unanesthetized restrained rats.

Cholinergic and GABAergic neurons in the medial septum-diagonal band of Broca (MS-DB) project to the hippocampus where they are involved in generating theta rhythmicity. So far, the functional properties of neurochemically identified MS-DB neurons are not fully characterized. In this study, MS-DB neurons recorded in urethane anesthetized rats and in unanesthetized restrained rats were labeled with neurobiotin and processed for immunohistochemistry against glutamic acid decarboxylase (GAD), parvalbumin (PV), and choline acetyltransferase (ChAT).

Medial septal GABAergic neurons express the somatostatin sst2A receptor: functional consequences on unit firing and hippocampal theta.

GABAergic septohippocampal neurons play a major role in the generation of hippocampal theta rhythm, but modulatory factors intervening in this function are poorly documented. The neuropeptide somatostatin (SST) may be one of these factors, because nearly all hippocampal GABAergic neurons projecting to the medial septum/diagonal band of Broca (MS-DB) express SST. In this study, we took advantage of the high and selective expression of the SST receptor sst2A in MS-DB to examine its possible role on theta-related activity.

Ultradian rhythmicity of ghrelin secretion in relation with GH, feeding behavior, and sleep-wake patterns in rats.

Ghrelin, an endogenous ligand for the GHS receptor, stimulates GH secretion and gastrointestinal motility and has orexigenic effects. In this study, the relationships between ghrelin, GH secretion, feeding behavior, and sleep-wake patterns were investigated in adult male rats. The half-life of exogenous ghrelin (10 microg i.