Chronic Exposure to Morphine Leads to a Reduced Affective Pain Response in the Presence of Hyperalgesia in an Animal Model of Empathy.

BACKGROUND: Empathy is the capability to represent the mental and emotional states of other subjects. Previous studies have demonstrated a possible correlation between morphine addiction and altered empathy response in morphine-addicted subjects. This study was performed to evaluate the effect of chronic morphine exposure as an animal model of morphine addiction on empathic changes in affective and sensory pain. METHODS: Adult male Wistar rats (3 months old) were used for the current study. Animals were grouped in cages of two (n = 8 for each group) and one animal was selected as the pain observer group. Pain observer animals received either saline or morphine (10 mg/kg, twice daily for 8 days). At ninth day, formalin [50 µg, 5%, subcutaneous (SC)] was injected into the hindpaw of the cagemate and placed inside the cage. Elevated plus maze (EPM) and open field test (OFT) were recruited to evaluate anxiety; hot plate and tail flick tests were used to assay sensory pain. Conditioned place aversion (CPA) was also measured as indicator of affective pain component. FINDINGS: Chronic morphine exposure led to a reduced level of anxiety in EPM and OFT assays. An opioid-induced hyperalgesia was observed in the sensory pain assays, while there was a reduced affective pain in the CPA paradigm in morphine-treated animals. CONCLUSION: It might be plausible that chronic morphine exposure might alter empathy for pain through affective and not sensory pain pathways.

A Highlighted Case for Emphasizing on Clinical Diagnosis for Rare Syndrome in Third World.

Premature tooth loss is a disastrous situation that affects deciduous or permanent teeth era with different causes. It may be attributed to some disorders like Papillon-Lefevre syndrome or coffin-lowry syndrome but because of ambiguous nature, precise diagnosis is not easily possible. Moreover, it has very low incidence and defines by few and limited case series, with vague characters to some extent, confusion in detecting the right diagnosis is a common possibility. Hence, it is expectable to have a wrong diagnosis for this case. In this study, a 5-yr-old boy with chief complaint of early tooth loss despite having blindness in left eye and palmar keratosis is reported, although he had some other manifestation of oculodentodigital dysplasia (ODDD) like ataxia, dysarthria and nail deformity, ignoring other extra and intra oral finding. He was diagnosed as Papillon-Lefevre syndrome already, just because of early tooth loss and palmar keratosis.