Diversity of ancestral brainstem noradrenergic neurons across species and multiple biological factors.

The brainstem region, locus coeruleus (LC), has been remarkably conserved across vertebrates. Evolution has woven the LC into wide-ranging neural circuits that influence functions as broad as autonomic systems, the stress response, nociception, sleep, and high-level cognition among others. Given this conservation, there is a strong possibility that LC activity is inherently similar across species, and furthermore that age, sex, and brain state influence LC activity similarly across species.

Pro-opiomelanocortin neurons in the nucleus of the solitary tract mediate endorphinergic endogenous analgesia in mice.

The nucleus of the solitary tract (NTS) contains pro-opiomelanocortin (POMC) neurons that are 1 of the 2 major sources of β-endorphin in the brain. The functional role of these NTS POMC neurons in nociceptive and cardiorespiratory function is debated. We have shown that NTS POMC optogenetic activation produces bradycardia and transient apnoea in a working heart-brainstem preparation and chemogenetic activation with an engineered ion channel (PSAM) produced opioidergic analgesia in vivo.

Interventions to treat pain in paediatric CFS/ME: a systematic review.

Background: Paediatric chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is common (prevalence 1%-2%). Two-thirds of children experience moderate or severe pain, which is associated with increased fatigue and poorer physical function. However, we do not know if treatment for CFS/ME improves pain.

Systemic dexmedetomidine augments inhibitory synaptic transmission in the superficial dorsal horn through activation of descending noradrenergic control: an in vivo patch-clamp analysis of analgesic mechanisms.

α2-Adrenoceptors are widely distributed throughout the central nervous system (CNS) and the systemic administration of α2-agonists such as dexmedetomidine produces clinically useful, centrally mediated sedation and analgesia; however, these same actions also limit the utility of these agents (ie, unwanted sedative actions). Despite a wealth of data on cellular and synaptic actions of α2-agonists in vitro, it is not known which neuronal circuits are modulated in vivo to produce the analgesic effect. To address this issue, we made in vivo recordings of membrane currents and synaptic activities in superficial spinal dorsal horn neurons and examined their responses to systemic dexmedetomidine.

Tactile allodynia in patients with postherpetic neuralgia: lack of change in skin blood flow upon dynamic stimulation.

Tactile allodynia is a common, troublesome feature of neuropathic pain. Allodynia has been proposed to involve abnormal Abeta-afferent coupling in the dorsal horn resulting in C-fibre activation and increased skin blood flow (SBF). Thus, changes in SBF could provide an objective measure of allodynia.