scholarly journals Distinct role of nucleus accumbens D2-MSN projections to ventral pallidum in different phases of motivated behavior

2020 ◽  
Author(s):  
Carina Soares-Cunha ◽  
Raquel Correia ◽  
Ana Verónica Domingues ◽  
Bárbara Coimbra ◽  
Nivaldo AP de Vasconcelos ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Behavioral Effect ◽  
Ventral Pallidum ◽  
Medium Spiny Neurons ◽  
Motivated Behavior ◽  
Spiny Neurons ◽  
Reward Delivery ◽  
Instrumental Task ◽  
Motivated Behaviors

AbstractThe nucleus accumbens (NAc) is a key region in motivated behaviors. NAc medium spiny neurons (MSNs) are divided into those expressing dopamine receptor D1 or D2. Classically, D1- and D2-MSNs have been described as having opposing roles in reinforcement but recent evidence suggests a more complex role for D2-MSNs.Here we show that optogenetic modulation of D2-MSN to ventral pallidum (VP) projections during different stages of motivated behavior has contrasting effects in motivation. Activation of D2-MSN-VP projections during a reward-predicting cue results in increased motivational drive, whereas activation at reward delivery results in decreased motivation; optical inhibition has the opposite behavioral effect. In addition, in a free choice instrumental task, animals prefer the lever that originates one pellet in opposition to pellet plus D2-MSN-VP optogenetic activation, and vice versa for optogenetic inhibition.In summary, D2-MSN-VP projections play different (and even opposing) roles in distinct phases of motivated behavior.

scholarly journals Morphology of Human Nucleus Accumbens Neurons Based on the Immunohistochemical Expression of Gad67

2016 ◽  
Vol 17 (4) ◽  
pp. 297-302
Author(s):  
Maja Sazdanovic ◽  
Slobodanka Mitrovic ◽  
Milos Todorovic ◽  
Maja Vulovic ◽  
Dejan Jeremic ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Pyramidal Neurons ◽  
Immunohistochemical Analysis ◽  
Medium Spiny Neurons ◽  
Immunohistochemical Expression ◽  
Spiny Neurons ◽  
Different Types ◽  
Human Brains

Abstract The nucleus accumbens is a part of the ventral striatum along with the caudate nucleus and putamen. The role of the human nucleus accumbens in drug addiction and other psychiatric disorders is of great importance. The aim of this study was to characterize medium spiny neurons in the nucleus accumbens according to the immunohistochemical expression of GAD67. This study was conducted on twenty human brains of both sexes between the ages of 20 and 75. The expression of GAD67 was assessed immunohistochemically, and the characterization of the neurons was based on the shape and size of the soma and the number of impregnated primary dendrites. We showed that neurons of the human nucleus accumbens expressed GAD67 in the neuron soma and in the primary dendrites. An analysis of the cell body morphology revealed the following four different types of neurons: fusiform neurons, fusiform neurons with lateral dendrites, pyramidal neurons and multipolar neurons. An immunohistochemical analysis showed a strong GAD67 expression in GABAergic medium spiny neurons, which could be classifi ed into four different types, and these neurons morphologically correlated with those described by the Golgi study.

scholarly journals Selective filtering of excitatory inputs to nucleus accumbens by dopamine and serotonin

2021 ◽  
Vol 118 (24) ◽  
pp. e2106648118
Author(s):  
Daniel J. Christoffel ◽  
Jessica J. Walsh ◽  
Paul Hoerbelt ◽  
Boris D. Heifets ◽  
Pierre Llorach ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Basolateral Amygdala ◽  
Behavioral Effects ◽  
Medium Spiny Neurons ◽  
Excitatory Postsynaptic Currents ◽  
Spiny Neurons ◽  
Specific Manner ◽  
Paraventricular Thalamus ◽  
Motivated Behaviors ◽  
Synaptic Effects

The detailed mechanisms by which dopamine (DA) and serotonin (5-HT) act in the nucleus accumbens (NAc) to influence motivated behaviors in distinct ways remain largely unknown. Here, we examined whether DA and 5-HT selectively modulate excitatory synaptic transmission in NAc medium spiny neurons in an input-specific manner. DA reduced excitatory postsynaptic currents (EPSCs) generated by paraventricular thalamus (PVT) inputs but not by ventral hippocampus (vHip), basolateral amygdala (BLA), or medial prefrontal cortex (mPFC) inputs. In contrast, 5-HT reduced EPSCs generated by inputs from all areas except the mPFC. Release of endogenous DA and 5-HT by methamphetamine (METH) and (±)3,4-methylenedioxymethamphetamine (MDMA), respectively, recapitulated these input-specific synaptic effects. Optogenetic inhibition of PVT inputs enhanced cocaine-conditioned place preference, whereas mPFC input inhibition reduced the enhancement of sociability elicited by MDMA. These findings suggest that the distinct, input-specific filtering of excitatory inputs in the NAc by DA and 5-HT contribute to their discrete behavioral effects.

scholarly journals Error-related Signaling in Nucleus Accumbens D2 Receptor-expressing Neurons Guides Avoidance-based Goal-directed Behavior

2022 ◽  
Author(s):  
Tadaaki Nishioka ◽  
Tom Macpherson ◽  
Kosuke Hamaguchi ◽  
Takatoshi Hikida
Keyword(s):  
Nucleus Accumbens ◽  
Behavioral Control ◽  
D2 Receptor ◽  
Environmental Cues ◽  
Medium Spiny Neurons ◽  
Spiny Neurons ◽  
Cell Type Specific ◽  
Goal Directed Behavior

Abstract Learnt associations between environmental cues and the outcomes they predict (cue-outcome associations) play a major role in behavioral control, guiding not only which responses we should perform, but also which we should avoid, in order to achieve a specific goal. The encoding of such cue-outcome associations, as well as the performance of cue-guided goal-directed behavior, is thought to involve dopamine D1 and D2 receptor-expressing medium spiny neurons (D1-/D2-MSNs) of the nucleus accumbens (NAc). Here, using a visual discrimination task in mice, we assessed the role of NAc D1-/D2-MSNs in cue-guided goal-directed avoidance of inappropriate responding. Cell-type specific neuronal silencing and in-vivo imaging revealed NAc D2-MSNs to selectively contribute to cue-guided avoidance behavior, with activation of NAc D2-MSNs following response error playing an important role in optimizing future goal-directed behavior. Our findings indicate that error-signaling by NAc D2-MSNs underlies the ability to use environmental cues to avoid inappropriate behavior.

scholarly journals Circuit directionality for motivation: lateral accumbens-pallidum, but not pallidum-accumbens, connections regulate motivational attraction to reward cues

2018 ◽  
Author(s):  
Elizabeth B. Smedley ◽  
Alyssa DiLeo ◽  
Kyle S. Smith
Keyword(s):  
Nucleus Accumbens ◽  
Designer Drugs ◽  
Ventral Pallidum ◽  
Incentive Salience ◽  
Delivery Strategy ◽  
Sign Tracking ◽  
Motivated Behavior ◽  
Reciprocal Connections ◽  
Motivated Behaviors ◽  
Tracking Behavior

AbstractSign-tracking behavior, in which animals interact with a cue that predicts reward, provides an example of how incentive salience can be attributed to cues and elicit motivation. The nucleus accumbens (NAc) and ventral pallidum (VP) are two regions involved in cue-driven motivation. The VP, and subregions of the NAc including the medial shell and core, are critical for sign-tracking, and connections between the medial shell and VP are known to participate in sign-tracking and other motivated behaviors. The NAc lateral shell (NAcLSh) is a distinct and understudied subdivision of the NAc, and its contribution to the process by which reward cues acquire value remains unclear. The NAcLSh has been implicated in reward-directed behavior, and has reciprocal connections with the VP, suggesting that NAcLSh and VP interactions could be important mechanisms for incentive salience. Here, we use DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) and an intersectional viral delivery strategy to produce a biased inhibition of NAcLSh neurons projecting to the VP, and vice versa. We find that disruption of connections from NAcLSh to VP reduces sign-tracking behavior while not affecting consumption of food rewards. In contrast, VP to NAcLSh disruption affected neither sign-tracking nor reward consumption, but did produce a greater shift in animals’ behavior more towards the reward source when it was available. These findings indicate that the NAcLSh→VP pathway plays an important role in guiding animals towards reward cues, while VP→NAcLSh back-projections may not and may instead bias motivated behavior towards rewards.

scholarly journals Microglial NFκB-TNFα hyperactivation induces obsessive–compulsive behavior in mouse models of progranulin-deficient frontotemporal dementia

2017 ◽  
Vol 114 (19) ◽  
pp. 5029-5034 ◽  
Author(s):  
Grietje Krabbe ◽  
S. Sakura Minami ◽  
Jon I. Etchegaray ◽  
Praveen Taneja ◽  
Biljana Djukic ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Frontotemporal Dementia ◽  
Knockout Mice ◽  
Nuclear Factor Κb ◽  
Medium Spiny Neurons ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Spiny Neurons ◽  
Increased Risk ◽  
Excessive Grooming

Frontotemporal dementia (FTD) is the second most common dementia before 65 years of age. Haploinsufficiency in the progranulin (GRN) gene accounts for 10% of all cases of familial FTD. GRN mutation carriers have an increased risk of autoimmune disorders, accompanied by elevated levels of tissue necrosis factor (TNF) α. We examined behavioral alterations related to obsessive–compulsive disorder (OCD) and the role of TNFα and related signaling pathways in FTD patients with GRN mutations and in mice lacking progranulin (PGRN). We found that patients and mice with GRN mutations displayed OCD and self-grooming (an OCD-like behavior in mice), respectively. Furthermore, medium spiny neurons in the nucleus accumbens, an area implicated in development of OCD, display hyperexcitability in PGRN knockout mice. Reducing levels of TNFα in PGRN knockout mice abolished excessive self-grooming and the associated hyperexcitability of medium spiny neurons of the nucleus accumbens. In the brain, PGRN is highly expressed in microglia, which are a major source of TNFα. We therefore deleted PGRN specifically in microglia and found that it was sufficient to induce excessive grooming. Importantly, excessive grooming in these mice was prevented by inactivating nuclear factor κB (NF-κB) in microglia/myeloid cells. Our findings suggest that PGRN deficiency leads to excessive NF-κB activation in microglia and elevated TNFα signaling, which in turn lead to hyperexcitability of medium spiny neurons and OCD-like behavior.

scholarly journals Sex-Specific Role for Egr3 in Nucleus Accumbens D2-Medium Spiny Neurons Following Long-Term Abstinence From Cocaine Self-administration

2020 ◽  
Vol 87 (11) ◽  
pp. 992-1000 ◽  
Author(s):  
Michel Engeln ◽  
Swarup Mitra ◽  
Ramesh Chandra ◽  
Utsav Gyawali ◽  
Megan E. Fox ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Specific Role ◽  
Medium Spiny Neurons ◽  
Self Administration ◽  
Spiny Neurons

scholarly journals Putative role of pharmacogenetics to elucidate the mechanism of tardive dyskinesia in schizophrenia

2019 ◽  
Vol 20 (17) ◽  
pp. 1199-1223 ◽  
Author(s):  
Anton JM Loonen ◽  
Bob Wilffert ◽  
Svetlana A Ivanova
Keyword(s):  
Oxidative Stress ◽  
Tardive Dyskinesia ◽  
Genetic Variants ◽  
Long Term Potentiation ◽  
Specific Gene ◽  
Medium Spiny Neurons ◽  
Spiny Neurons ◽  
Long Term Treatment

Identifying biomarkers which can be used as a diagnostic tool is a major objective of pharmacogenetic studies. Most mental and many neurological disorders have a compiled multifaceted nature, which may be the reason why this endeavor has hitherto not been very successful. This is also true for tardive dyskinesia (TD), an involuntary movement complication of long-term treatment with antipsychotic drugs. The observed associations of specific gene variants with the prevalence and severity of a disorder can also be applied to try to elucidate the pathogenesis of the condition. In this paper, this strategy is used by combining pharmacogenetic knowledge with theories on the possible role of a dysfunction of specific cellular elements of neostriatal parts of the (dorsal) extrapyramidal circuits: various glutamatergic terminals, medium spiny neurons, striatal interneurons and ascending monoaminergic fibers. A peculiar finding is that genetic variants which would be expected to increase the neostriatal dopamine concentration are not associated with the prevalence and severity of TD. Moreover, modifying the sensitivity to glutamatergic long-term potentiation (and excitotoxicity) shows a relationship with levodopa-induced dyskinesia, but not with TD. Contrasting this, TD is associated with genetic variants that modify vulnerability to oxidative stress. Reducing the oxidative stress burden of medium spiny neurons may also be the mechanism behind the protective influence of 5-HT2 receptor antagonists. It is probably worthwhile to discriminate between neostriatal matrix and striosomal compartments when studying the mechanism of TD and between orofacial and limb-truncal components in epidemiological studies.

Sign in / Sign up

Export Citation Format

Share Document