Chemogenetic modulation of accumbens direct or indirect pathways bidirectionally alters reinstatement of heroin-seeking in high- but not low-risk rats.
Neuropsychopharmacology
; 45(8): 1251-1262, 2020 07.
Article
em En
| MEDLINE
| ID: mdl-31747681
ABSTRACT
Opioid addiction has been declared a public health emergency, with fatal overdoses following relapse reaching epidemic proportions and disease-associated costs continuing to escalate. Relapse is often triggered by re-exposure to drug-associated cues, and though the neural substrates responsible for relapse in vulnerable individuals remains ambiguous, the nucleus accumbens (NAc) has been shown to play a central role. NAc direct and indirect pathway medium spiny neurons (dMSNs and iMSNs) can have oppositional control over reward-seeking and associative learning and are critically involved in reinstatement of psychostimulant-seeking. However, whether these pathways similarly regulate reinstatement of opioid-seeking remains unknown, as is their role in modulating motivation to take opioids. Here, we describe a method for classifying addiction severity in outbred rats following intermittent-access heroin self-administration that identifies subgroups as addiction-vulnerable (high-risk) or addiction-resistant (low-risk). Using dual viral-mediated gene transfer of DREADDs, we show that transient inactivation of dMSNs or activation of iMSNs is capable of suppressing cue-induced reinstatement of heroin-seeking in high- but not low-risk rats. Surprisingly, however, the motivation to self-administer heroin was unchanged, indicating a divergence in the encoding of heroin-taking and heroin-seeking in rats. We further show that transient activation of dMSNs or inactivation of iMSNs exacerbates cue-induced reinstatement of heroin-seeking in high- but not low-risk rats, again with no effect on motivation. These findings demonstrate a critical role for dMSNs and iMSNs in encoding vulnerability to reinstatement of heroin-seeking and provide insight into the specific neurobiological changes that occur in vulnerable groups following heroin self-administration.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Heroína
/
Dependência de Heroína
Tipo de estudo:
Etiology_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article