Morphine-alcohol treatment impairs cognitive functions and increases neuro-inflammatory responses in the medial prefrontal cortex of juvenile male rats

Abstract

In the developed and developing world, opioid consumption in combination with alcohol has become one of the substances abused. In this experiment, we examined the effects of alcohol, morphine, and morphine+alcohol combination on cognitive functions and neuroinflammatory responses in the medial prefrontal cortex (mPFC) of juvenile male rats. Alcohol (1.0 ml of 15% v/v ethanol twice daily, subcutaneously, 7 hours apart), morphine (0.5 ml/kg of 0.4 mg/kg morphine chlorate twice daily, subcutaneously, 7 hours apart), morphine+alcohol co-treatment (0.5 ml/kg of 0.4 mg/kg morphine chlorate+1.0 ml of 15% v/v ethanol twice daily, subcutaneously, 7 hours apart) were administered for 21 days. Treatment with morphine+alcohol significantly impairs cognition functions in the Morris water maze, passive avoidance, and novel object recognition tests, furthermore, the treatment significantly increased the quantitative count of astrocytic cells and also conferred marked neuronal cell death in the mPFC, which were studied by glial fibrillary acidic protein immunochemistry for astrocytes and Cresyl violet for Nissl's substance distribution in neurons respectively. These results suggest that alcohol, morphine, and morphine+alcohol co-treatment may trigger cognitive deficits and neuroinflammatory responses in the brain.

Investigating the Co-administration of Ghrelin and Nicotine into the Medial Septum and Its Influencing on Morphine Amnestic Effect

“…Consistent with prior results (Adedayo et al, 2018;Ghasemzadeh and Rezayof, 2017;Tavassoli et al, 2020), in the present study, morphine administration cause to passive avoidance memory consolidation impairment. Previously, it has been shown that morphine-induced memory impairment results from changes in CAMKII/CREB and also BDNF/cFos signaling pathways Rezayof, 2016, 2018).…”

“…Passive avoidance learning is a hippocampus-dependent simple task which widely use in memory studies in rodents (Atucha and Roozendaal et al, 2015). According to previous studies, acute exposure to morphine could affect various aspects of memory formation in avoidance learning (Adedayo et al, 2018;Ghasemzadeh and Rezayof, 2017;Tavassoli et al, 2020). Our previous studies showed that injection of ghrelin into the hippocampus or anterior port of ventral tegmental area (VTA) improved morphine-induced memory impairment and this improvement is associated with the acetylcholine nicotinic receptor activity (Nazari-Serenjeh et al, 2019;Yadegay et al, 2020).…”

Curcumin supplementation shows modulatory influence on functional and morphological features of hippocampus in mice subjected to arsenic trioxide exposure

“…An association between chronic inorganic arsenic exposure and CNS malfunctioning such as deficits in intelligence, verbal comprehension, attention, learning, and memory have been reported [ 48 , 49 ]. Cognitive deficits in animal models following exposure to substances of abuse such as alcohol and morphine have also been reported [ 50 ]. Hippocampus is one of the key areas involved in learning, memory, emotions and cognitive map formation [ 18 ].…”

Mechanism of psychoactive substance-induced cognitive disorders: does tau protein play a role?

“…Memory impairment was detected by dark compartment test in male mice [32] and radial maze test in male Sprague-Dawley (SD) rats [33]. As to the investigation of chronic effects on cognitive functions, researchers have found that morphine could impair spatial learning and memory [34][35][36][37], especially short-term [35,36]. Meanwhile, object location memory could be impaired when tested by objectlocation memory task and elevated plus maze testing [38].…”