Abstract
The ventral striatum, also called nucleus accumbens (NAc), has long been known to integrate information from cortical, thalamic, midbrain and limbic nuclei to mediate goal-directed behaviors. Until recently thalamic afferents have been overlooked when studying the functions and connectivity of the NAc. However, findings from recent studies have shed light on the importance and roles of precise Thalamus to NAc connections in motivated behaviors and in addiction. In this review, we summarize studies using techniques such as chemo- and optogenetics, electrophysiology and in vivo calcium imaging to elucidate the complex functioning of the thalamo-NAc afferents, with a particular highlight on the projections from the Paraventricular Thalamus (PVT) to the NAc. We will focus on the recent advances in the understanding of the roles of these neuronal connections in motivated behaviors, with a special emphasis on their implications in addiction, from cue-reward association to the mechanisms driving relapse.
Highlights
The nucleus accumbens (NAc), a key node of the reward brain circuitry, is known to be involved in several motivated behaviors and is notably responsible for translating motivation into action in goal-directed behaviors (Mogenson et al, 1980; Ikemoto and Panksepp, 1999; Carelli, 2002; Klawonn and Malenka, 2018; Yang et al, 2018)
In vivo two-photon calcium imaging of Paraventricular Thalamus (PVT) neurons projecting to the NAc Optogenetic inhibition Chemogenetic activation
Naloxone-precipitated opiate withdrawal conditioned place aversion (CPA) induced by spontaneous opiate withdrawal/mild footshock/LiCl intraperitoneal injection Chronic morphine exposure Reinstatement of cocaine self-administration after extinction
Summary
The nucleus accumbens (NAc), a key node of the reward brain circuitry, is known to be involved in several motivated behaviors and is notably responsible for translating motivation into action in goal-directed behaviors (Mogenson et al, 1980; Ikemoto and Panksepp, 1999; Carelli, 2002; Klawonn and Malenka, 2018; Yang et al, 2018). Drugs of abuse hijack normal adaptive changes in the brain that occur in a non-pathological context to drive reward-related learning and memory, thereby involving the NAc (Nestler, 2013). The NAc receives glutamatergic projections from cortical and thalamic areas in similar abundance (Phillipson and Griffiths, 1985; Doig et al, 2010). Thalamo-NAc Projections in Reward neuronal populations of the striatum, the D1- and D2-Medium Spiny Neurons (MSNs) as well as interneurons (Smith et al, 2004; Doig et al, 2010; Wall et al, 2013; Klug et al, 2018; Johansson and Silberberg, 2020). Thalamic afferents of the NAc have long been overlooked, recent studies have untangled their functional importance
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
