Methods To test our hypothesis, in the first set of experiments, we evaluated nociceptive
response after two consecutive injection of formalin (50µL, 2%), with intervals of 5 or 60 …

Injection of a dilute solution of formalin into a rat hindpaw produces a biphasic nociceptive
response consisting of an early phase during the first 5 min after formalin injection and a …

The formalin test is used as a primary behavioural screen for assaying the antinociceptive
activity of compounds in laboratory rodents. After hindpaw formalin injection, nociceptive …

This study focused on the antinociceptive action of morphine in the formalin test in rats.
Formalin-induced behaviour is characterised by two phases relevant to acute and tonic pain …

The roles of endogenous opioid peptides in the brain in the modulation of nocifensive
responses to formalin in ICR mice were studied. Mice were pretreated …

Naloxone is known to decrease, increase or have no effect on nociceptive thresholds. Here,
using two commonly accepted pain-related behaviors (licking and flinching) associated with …

This study assesses the effects of peripheral or intrathecal pre-treatment or post-treatment
with µ, δ, κ and nociceptin/orphanin FQ (NOP) opioid receptor agonists (morphine, U-50488 …

The formalin test in mice is a valid and reliable model of nociception and is sensitive for
various classes of analgesic drugs. The noxious stimulus is an injection of dilute formalin …

The orofacial formalin test in the rat is a valid and reliable model of nociception and is
sensitive to various classes of analgesic drugs. The noxious stimulus consists in an injection …

The effects of local treatment with opioid receptor agonists on the early (0–10 min) and late
(20–40 min) behavioural response and extravasation induced by intraplantar injection of 1 …