Role of nucleus accumbens microRNA-181a and MeCP2 in incubation of heroin craving in male rats

Abstract Background: Several studies have shown that glutamate neurotransmission in the nucleus accumbens (NAc) is required for the development of morphine-induced conditional place preference (CPP). Also, metabotropic glutamate receptors (mGluRs) into the NAc play important roles in the reward pathways. However, the precise role of mGluR4 in different steps of the morphine-induced CPP is less well known. In the present study we investigated the effect of bilateral intra-accumbal infusion of VU0155041, as a specific mGluR4 agonist on the acquisition and expression of morphine induced CPP in male Wistar rats. Animals were bilaterally implanted with guide cannulae above the NAc. In the first part of the study, the VU0155041 was administered at doses of 10, 30 and 50 μg/0.5 μL saline per side into the NAc during the 3 days of morphine (5 mg/kg) conditioning (acquisition) phase of morphine-induced CPP. In the next part of the study, the rats bilaterally received VU0155041 at the dose of 50 μg/0.5 μL, 5 min before the post-conditioning test to check the effect of VU0155041 on the expression of morphine-induced CPP. Results: The results showed that the intra-accumbal injection of VU0155041 inhibits the acquisition of morphine-induced CPP in a dose dependent manner, but had no effect on expression Our data indicated that intra-NAc administration of VU0155041 dose-dependently blocks the establishment of morphine-induced CPP and reduces the rewarding properties of morphine.These effects may be related to changes in glutamate activity in the NAC and/or learning dependent mechanism of glutamate neurotransmission in reward pathway(s).

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Role of prefrontal cortex projections to the nucleus accumbens core in mediating the effects of ceftriaxone on cued cocaine relapse

10.1101/2020.01.20.911792 ◽

2020 ◽

Author(s):

Allison R. Bechard ◽

Carly N. Logan ◽

Javier Mesa ◽

Yasmin Padovan Hernandez ◽

Harrison Blount ◽

...

Keyword(s):

Prefrontal Cortex ◽

Nucleus Accumbens ◽

Basolateral Amygdala ◽

Male Rats ◽

Self Administration ◽

Nucleus Accumbens Core ◽

Cocaine Seeking ◽

Context Cues ◽

Glutamate Efflux

AbstractCeftriaxone is an antibiotic that reliably attenuates the reinstatement of cocaine-seeking after extinction while preventing the nucleus accumbens (NA) core glutamate efflux that drives reinstatement. However, when rats undergo abstinence without extinction, ceftriaxone attenuates context-primed relapse but NA core glutamate efflux still increases. Here we sought to determine if the same would occur when relapse is prompted by both context and discrete cues (context+cues) after cocaine abstinence. Male rats self-administered intravenous cocaine for 2 hr/day for 2 weeks. Cocaine delivery was accompanied by drug-associated cues (light+tone). Rats were then placed into abstinence with daily handling but no extinction training for two weeks. Ceftriaxone (200 mg/kg IP) or vehicle was administered during the last 6 days of abstinence. During a context+cue relapse test, microdialysis procedures were conducted. Rats were perfused at the end of the test for later Fos analysis. A separate cohort of rats was infused with the retrograde tracer cholera toxin B in the NA core and underwent the same self-administration and relapse procedures. Ceftriaxone increased baseline glutamate and attenuated both context+cue-primed relapse and NA core glutamate efflux during this test. Ceftriaxone reduced Fos expression in regions sending projections to the NA core (prefrontal cortex, basolateral amygdala, ventral tegmental area) and specifically reduced Fos in prelimbic cortex and not infralimbic cortex neurons projecting to the NA core. Thus, when relapse is primed by drug-associated cues and context, ceftriaxone is able to attenuate relapse by preventing NA core glutamate efflux, likely through reducing activity in prelimbic NA core-projecting neurons.

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Social isolation of adolescent male rats increases anxiety and K + ‐induced dopamine release in the nucleus accumbens: Role of CRF‐R1

European Journal of Neuroscience ◽

10.1111/ejn.15345 ◽

2021 ◽

Author(s):

Javier Novoa ◽

Carlos J. Rivero ◽

Enrique U. Pérez‐Cardona ◽

Jaime A. Freire‐Arvelo ◽

Juan Zegers ◽

...

Keyword(s):

Nucleus Accumbens ◽

Social Isolation ◽

Dopamine Release ◽

Male Rats ◽

Adolescent Male

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The role of mGlu4 receptors within the nucleus accumbens in acquisition and expression of morphine-induced conditioned place preference in male rats

BMC Neuroscience ◽

10.1186/s12868-021-00627-2 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Zahra Ebrahimi ◽

Nazanin Kahvandi ◽

Alireza Komaki ◽

Seyed Asaad Karimi ◽

Marzieh Naderishahab ◽

...

Keyword(s):

Nucleus Accumbens ◽

Metabotropic Glutamate Receptors ◽

Place Preference ◽

Male Rats ◽

Dependent Manner ◽

Metabotropic Glutamate ◽

Male Wistar Rats ◽

Glutamate Neurotransmission ◽

Reward Pathways

Abstract Background Several studies have shown that glutamate neurotransmission in the nucleus accumbens (NAc) is required for the development of morphine-induced conditional place preference (CPP). In addition, metabotropic glutamate receptors (mGluRs) in NAc play important roles in the reward pathways. However, the precise role of mGluR4 in different steps of the morphine-induced CPP is less well known. In the present study the effect of bilateral intra-accumbal infusion of VU0155041, as a specific mGluR4 agonist on the acquisition and expression of morphine induced CPP in male Wistar rats was investigated. The animals were bilaterally implanted with guide cannulae above the NAc. In the first step of the study, the VU0155041 was administered at doses of 10, 30 and 50 μg/0.5 μL saline per side into the NAc during the 3 days of morphine (5 mg/kg) conditioning (acquisition) phase of morphine-induced CPP. In the second step of the study, the rats bilaterally received VU0155041 at the dose of 50 μg/0.5 μL, 5 min before the post-conditioning test in order to check the effect of VU0155041 on the expression of morphine-induced CPP. Results The results showed that the intra-accumbal injection of VU0155041 inhibits the acquisition of morphine-induced CPP in a dose dependent manner, but had no effect on expression. Conclusions The data indicated that intra-NAc administration of VU0155041 dose dependently blocks the establishment of morphine-induced CPP and reduces the rewarding properties of morphine. These effects may be related to changes in glutamate activity in the NAC and/or learning dependent mechanism of glutamate neurotransmission in reward pathway(s).

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