Morphological investigations of endomorphin-2 and spinoparabrachial projection neurons in the spinal dorsal horn of the rat.

It has been proved that endomorphin-2 (EM2) produced obvious analgesic effects in the spinal dorsal horn (SDH), which existed in our human bodies with remarkable affinity and selectivity for the μ-opioid receptor (MOR). Our previous study has demonstrated that EM2 made synapses with the spinoparabrachial projection neurons (PNs) in the SDH and inhibited their activities by reducing presynaptic glutamate release. However, the morphological features of EM2 and the spinoparabrachial PNs in the SDH have not been completely investigated.

[Spatiotemporal charactersitics of decoupling between land surface thermal environment and ecosystem ser-vice value in Pearl River Delta Urban Agglomeration, China].

The Pearl River Delta Urban Agglomeration (PRDUA) is a highly urbanized region in China. The urbanized climate, especially the heat island effect, has a significant impact on urban ecosystems and habitats. Based on MODIS land surface temperature (LST) data and land cover data in 2000, 2005, 2010, 2015, and 2019, we quantified the land surface thermal environment and ecosystem service value (ESV), analyzed the decoupling between LST and ESV in the PRDUA from 2000 to 2019 using the decoupling analysis model, revealed the trade-off between them, and analyzed the spatiotemporal variation of the synergistic state between LST and ESV in PRDUA.

A Neural Circuit from Thalamic Paraventricular Nucleus to Central Amygdala for the Facilitation of Neuropathic Pain.

As one of the thalamic midline nuclei, the thalamic paraventricular nucleus (PVT) is considered to be an important signal integration site for many descending and ascending pathways that modulate a variety of behaviors, including feeding, emotions, and drug-seeking. A recent study has demonstrated that the PVT is implicated in the acute visceral pain response, but it is unclear whether the PVT plays a critical role in the central processing of chronic pain. Here, we report that the neurons in the posterior portion of the PVT (pPVT) and their downstream pathway are involved in descending nociceptive facilitation regarding the development of neuropathic pain conditions in male rats.

Enkephalinergic Circuit Involved in Nociceptive Modulation in the Spinal Dorsal Horn.

Enkephalin (ENK) has been implicated in pain modulation within the spinal dorsal horn (SDH). Revealing the mechanisms underlying ENK analgesia entails the anatomical and functional knowledge of spinal ENK-ergic circuits. Herein, we combined morphological and electrophysiological studies to unravel local ENK-ergic circuitry within the SDH.

Nucleus tractus solitarius mediates hyperalgesia induced by chronic pancreatitis in rats.

Background: Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis (CP). We hypothesized that the nucleus tractus solitarius (NTS), a primary central site that integrates pancreatic afferents apart from the thoracic spinal dorsal horn, plays a key role in the pathogenesis of visceral hypersensitivity in a rat model of CP.

Aim: To investigate the role of the NTS in the visceral hypersensitivity induced by chronic pancreatitis.

Anterior insular cortex mediates hyperalgesia induced by chronic pancreatitis in rats.

Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis (CP), but cortical modulation of painful CP remains elusive. This study was designed to examine the role of anterior insular cortex (aIC) in the pathogenesis of hyperalgesia in a rat model of CP. CP was induced by intraductal administration of trinitrobenzene sulfonic acid (TNBS).

Endomorphin-2 Decreases Excitatory Synaptic Transmission in the Spinal Ventral Horn of the Rat.

Motor impairment is one of the serious side-effects of morphine, which is an exogenous agonist of the μ-opioid receptor (MOR) as well as a widely used analgesic drug in clinical practice for chronic pain treatment. Endomorphins (EMs, including EM-1 and EM-2), the most effective and specific endogenous agonists of the MOR, exert more potent analgesia in acute and neuropathic pain than other opiates, such as morphine. Although EMs had fewer side-effects comparing to other opiates, motor impairment was still one unwanted reaction which limited its clinical application.

Inhibitory effects of endomorphin-2 on excitatory synaptic transmission and the neuronal excitability of sacral parasympathetic preganglionic neurons in young rats.

The function of the urinary bladder is partly controlled by parasympathetic preganglionic neurons (PPNs) of the sacral parasympathetic nucleus (SPN). Our recent work demonstrated that endomorphin-2 (EM-2)-immunoreactive (IR) terminals form synapses with μ-opioid receptor (MOR)-expressing PPNs in the rat SPN. Here, we examined the effects of EM-2 on excitatory synaptic transmission and the neuronal excitability of the PPNs in young rats (24-30 days old) using a whole-cell patch-clamp approach.

[Experimental study on the protective effect of anisodamine on flaps with ischemia reperfusion injury].

Objective: To observe the effect of anisodamine (Ani) injection on the survival rate and histologic result of flaps with ischemia-reperfusion injury, so as to demonstrate the protective effect of Ani on the flap survival.

Methods: A total of 48 healthy male Wistar rats were randomly divided into model control, normal saline(NS) and anisodamine groups, with 16 rats in each group. An 3 cm x 6 cm axial flap was formed at the right lower abdomen with abdominal superficial blood vessel as the pedicle.