Drugs able to inhibit calmodulin activation can prevent some consequences of the rise in intracellular calcium. It has recently been shown that intrathecal injection of calmodulin inhibitors induce analgesia in rats. We study here the effect induced by the calmodulin inhibitor, calmidazolium, on the activity of dorsal horn neurons driven by noxious and non-noxious stimuli. Extracellular recordi...

Sharks are important exhibit animals in aquariums and zoologic institutions worldwide. Although veterinarians are encountering these species more frequently in these institutions, our knowledge regarding safe restraint and anesthesia is limited. To date there have been only a few anecdotal reports or studies evaluating the effects of tricaine methane sulfonate (MS-222), ketamine hydrochloride, ...

Gastroesophageal reflux (GER) frequently triggers or worsens cardiac pain or symptoms in patients with coronary heart disease. This study aimed to determine whether GER enhances the activity of upper thoracic spinal neurons receiving noxious cardiac input. Gastric fundus and pyloric ligations as well as a longitudinal myelotomy at the gastroesophageal junction induced acute GER in pentobarbital...

Painful diabetic neuropathy (PDN) is characterized by hyperalgesia i.e., increased sensitivity to noxious stimulus, and allodynia i.e., hypersensitivity to normally innocuous stimuli. Hyperalgesia and allodynia have been studied in many different rodent models of diabetes mellitus. However, as stated by Bölcskei et al, determination of "pain" in animal models is challenging due to its subjectiv...

Hyperactivity of the glutamatergic system is involved in the development of central sensitization in the pain neuraxis, associated with allodynia and hyperalgesia observed in patients with chronic pain. Herein we study the ability of type 4 metabotropic glutamate receptors (mGlu4) to regulate spinal glutamate signaling and alleviate chronic pain. We show that mGlu4 are located both on unmyelina...

BACKGROUND There is growing evidence supporting a role for TRPA1 receptors in the neurotransmission of peripheral mechanical stimulation. In order to enhance understanding of TRPA1 contributions to mechanotransmission, we examined the effects a selective TRPA1 receptor antagonist, A-967079, on spinal neuronal activity following peripheral mechanical stimulation in uninjured, CFA-inflamed, and o...

Hippocampal neurons fire spikes when an animal is at a particular location or performs certain behaviors in a particular place, providing a cellular basis for hippocampal involvement in spatial learning and memory. In a natural environment, spatial memory is often associated with potentially dangerous sensory experiences such as noxious or painful stimuli. The central sites for such pain-associ...

The experiment explored the influence of glutamic acid (Glu) and the NMDA-receptor antagonist dizocilpine maleate (MK-801) on the pain-evoked responses of pain-excitation neurons (PEN) in the nucleus accumbens (NAc) of rats. The trains of electric impulses applied to the sciatic nerve were used as noxious stimulation. The discharges of PEN in NAc were recorded by glass microelectrode. We observ...

Suppression of reactions to one noxious stimulus by a spatially distant noxious stimulus is termed heterotopic antinociception. In lightly anesthetized rats, a noxious visceral stimulus, colorectal distension (CRD), suppressed motor withdrawals but not blood pressure or heart rate changes evoked by noxious hindpaw heat. Microinjection of muscimol, a GABA(A) receptor agonist, into raphe magnus (...

Release of glutamate during inflammation and injury changes sensitivity and transmission efficiency of noxious sensory information via glutamate receptors. We found that activation of metabotropic glutamate receptor type 5 (mGluR5) transiently increased, and then subsequently decreased, noxious heat sensitivity. Similarly, mGluR5 activation in cultured sensory neurons potentiated intracellular ...