백서 중격의지핵과 전전주엽 피질 절편에서 도파민유리에 대한 Opioids의 효과 = Effect of Opioids on the High potassium-stimulated Release of Dopamine in Slices of Nucleus Accumbens and Prefrontal Cortex of the Rat

국문 초록 (Abstract)

중격의지핵 (nucleus accumbens, NAc)과 전전두엽 피질 절편 (prefrontal cortex, PFC)에 분포하는 dopamine (DA)성 신경은 reinforcement와 관련되어있으며 백서의 NAc와 PFC에서 DA의 유리를 매개하는 오피오이드 수용체를 구명하고자 고칼륨으로 자극한 [3H]DA의 유리에 대한 제종 오피오이드의 효과를 검토한 결과 opioid의 백서 NAc와 PFC에서 고칼륨에 의해 유발된 [3H]DA의 유리억제효과는 opioid κ 그리고 ORL-1 수용체에 의해 매개된다는 사실을 확인하였기에 문헌고찰과 함께 보고하는 바이다.

다국어 초록 (Multilingual Abstract)

Dopaminergic system in nucleus accumbens (NAc) and prefrontal cortex (PFC) plays an important role in the reinforcement. Opioids are capable of regulating dopamine (DA) release in various dopaminergic nerve endings. In this study, we examined the effect of opioids on the high potassium (20 mM)-stimulated DA release in rat NAc and PFC slices. High potassium (20 mM)-stimulated release of [3H]DA from NAc and PFC slices was enhanced by nomifensin, a DA transporter blocker, and domperidone, a presynaptic DAergic antagonist. The stimulated [3H]DA release was attenuated by removal of Ca2+ in artificual cerebrospinal fluid, and abolished by tetrodotoxin (1 μM) in both NAc and PFC slices. Agonists for opioid κ (U-50488H; U50) and opioid-like receptor-1 (ORL-1) (nociceptin; NC) inhibited the stimulated [3H]DA release, respectively. However, DPDPE, a selective opioid δ receptor agonist, and DAMGO, a selective opioid μ receptor agonist, did not influence the [3H]DA release in NAc and PFC slice preparations. The inhibitory effect of U50 on high potassium (20 mM)-stimulated DA release from NAc and PFC slices were antagonized by both nalxone, and nor-binaltorphimine (nor-BNI), a selective κ agonist. NC inhibited the stimulated release of [3H]DA in NAc and PFC slices, and it`s effect was antagonized by a selective ORL-1 antagonist, [Nphe1]nociceptin(1-13)NH2 (Phe-NC), but not by naloxone. These results suggest that stimulated release of [3H]DA is regulated by opioid κ and ORL-1 receptors, but not by δ receptors in rat NAc and PFC.