scholarly journals Enhanced habit formation in Tourette syndrome: dopamine release and striatal disinhibition modulate shortcut connections in a hierarchical model of cortico-basal ganglia loops

2021 ◽  
Author(s):  
Carolin Scholl ◽  
Javier Baladron ◽  
Julien Vitay ◽  
Fred H. Hamker

AbstractIn the Gilles de la Tourette syndrome, tics are often considered as habitual responses towards unwanted premonitory urges. Support for the relationship between tics and habits comes from devaluation protocols, which reveal that unmedicated Tourette patients show an increased tendency towards responses to devalued outcomes. We use a neuro-computational model of hierarchically organized cortico-basal ganglia-thalamo-cortical loops to shed more light on enhanced habit formation of Tourette patients. In our model, habitual behavior emerges from cortico-thalamic shortcut connections, where enhanced habit formation can be linked to faster plasticity in the shortcut or to a stronger feedback from the shortcut to the basal ganglia. Irregular activity in such shortcut connections may have different pathophysiological origins. Based on our model, we explore decreased local striatal inhibition, which may correspond to a loss of inhibitory interneurons, and increased dopaminergic modulation of striatal medium spiny neurons as causes for irregular shortcut plasticity or activation. Both lead to higher rates of response towards devalued outcomes in our model, similar to what is observed in Tourette patients. Our results support the view of tics in Tourette syndrome as maladaptive habits. We suggest to reveal more shortcuts between cortico-basal ganglia-thalamo-cortical loops in the human brain and study their potential role in the development of the Tourette syndrome.

2012 ◽  
Vol 108 (6) ◽  
pp. 1739-1751 ◽  
Author(s):  
Luis A. Tellez ◽  
Isaac O. Perez ◽  
Sidney A. Simon ◽  
Ranier Gutierrez

Neurons in the nucleus accumbens (NAc) have been shown to participate in several behavioral states, including feeding and sleep. However, it is not known if the same neuron participates in both states and, if so, how similar are the responses. In addition, since the NAc contains several cell types, it is not known if each type participates in the transitions associated with feeding and sleep. Such knowledge is important for understanding the interaction between two different neural networks. For these reasons we recorded ensembles of NAc neurons while individual rats volitionally transitioned between the following states: awake and goal directed, feeding, quiet-awake, and sleeping. We found that during both feeding and sleep states, the same neurons could increase their activity (be activated) or decrease their activity (be inactivated) by feeding and/or during sleep, thus indicating that the vast majority of NAc neurons integrate sleep and feeding signals arising from spatially distinct neural networks. In contrast, a smaller population was modulated by only one of the states. For the majority of neurons in either state, we found that when one population was excited, the other was inhibited, suggesting that they act as a local circuit. Classification of neurons into putative interneurons [fast-spiking interneurons (pFSI) and choline acetyltransferase interneurons (pChAT)] and projection medium spiny neurons (pMSN) showed that all three types are modulated by transitions to and from feeding and sleep states. These results show, for the first time, that in the NAc, those putative inhibitory interneurons respond similarly to pMSN projection neurons and demonstrate interactions between NAc networks involved in sleep and feeding.


2020 ◽  
Author(s):  
Bruno F. Cruz ◽  
Sofia Soares ◽  
Joseph J. Paton

SummaryImbalance between action suppression and production characterizes several basal ganglia (BG) disorders. Relatedly, the direct and indirect pathways of the BG are hypothesized to promote and suppress actions, respectively. Yet striatal direct (dMSNs) and indirect (iMSNs) medium spiny neurons are coactive around movement, apparently contradicting direct-indirect functional opponency. In the dorsolateral striatum of mice, we observed coactivation around movements, but elevated and diminished activity of iMSNs and dMSNs, respectively, during action suppression. Furthermore, relative activity of the two hemispheres evolved in opposite directions in the two pathways as the need to suppress movements to either side of the body developed over time. Lastly, optogenetic inhibition experiments revealed the necessity of iMSNs but not dMSNs for the proactive suppression of specific actions, and dMSNs but not iMSNs for generalized action vigor. These data demonstrate distinct yet still broadly opponent roles for the direct and indirect pathways in behavioral control.


2021 ◽  
Author(s):  
Zhaorong Chen ◽  
Zhi-Yu Zhang ◽  
Taorong Xie ◽  
Wen Zhang ◽  
Yaping Li ◽  
...  

SUMMARYDrinking behavior in rodents is characterized by stereotyped, rhythmic licking movement, which is regulated by the basal ganglia. It is unclear how direct and indirect pathways control the lick bout and individual lick event. We find that inactivating D1 and D2 receptors-expressing medium spiny neurons (MSNs) in the ventrolateral striatum (VLS) oppositely alters the number of licks in a bout. D1- and D2-MSNs exhibit similar patterns of lick sequence-related activity but different phases of oscillation time-locked to the lick cycle. On timescale of a lick cycle, transient inactivation of D1-MSNs during tongue protrusion reduces lick probability, whereas transient inactivation of D2-MSNs has no effect. On timescale of a lick bout, inactivation of D1-MSNs (D2-MSNs) causes rate increase (decrease) in a subset of basal ganglia output neurons that decrease firing during licking. Our results reveal the distinct roles of D1- and D2-MSNs in regulating licking at both coarse and fine timescales.


2015 ◽  
Vol 113 (3) ◽  
pp. 843-855 ◽  
Author(s):  
Morgane Pidoux ◽  
Tejapratap Bollu ◽  
Tori Riccelli ◽  
Jesse H. Goldberg

Across species, complex circuits inside the basal ganglia (BG) converge on pallidal output neurons that exhibit movement-locked firing patterns. Yet the origins of these firing patterns remain poorly understood. In songbirds during vocal babbling, BG output neurons homologous to those found in the primate internal pallidal segment are uniformly activated in the tens of milliseconds prior to syllable onsets. To test the origins of this remarkably homogenous BG output signal, we recorded from diverse upstream BG cell types during babbling. Prior to syllable onsets, at the same time that internal pallidal segment-like neurons were activated, putative medium spiny neurons, fast spiking and tonically active interneurons also exhibited transient rate increases. In contrast, pallidal neurons homologous to those found in primate external pallidal segment exhibited transient rate decreases. To test origins of these signals, we performed recordings following lesion of corticostriatal inputs from premotor nucleus HVC. HVC lesions largely abolished these syllable-locked signals. Altogether, these findings indicate a striking homogeneity of syllable timing signals in the songbird BG during babbling and are consistent with a role for the indirect and hyperdirect pathways in transforming cortical inputs into BG outputs during an exploratory behavior.


2019 ◽  
Vol 122 (6) ◽  
pp. 2294-2303 ◽  
Author(s):  
Marko Filipović ◽  
Maya Ketzef ◽  
Ramon Reig ◽  
Ad Aertsen ◽  
Gilad Silberberg ◽  
...  

Striatal projection neurons, the medium spiny neurons (MSNs), play a crucial role in various motor and cognitive functions. MSNs express either D1- or D2-type dopamine receptors and initiate the direct-pathway (dMSNs) or indirect pathways (iMSNs) of the basal ganglia, respectively. dMSNs have been shown to receive more inhibition than iMSNs from intrastriatal sources. Based on these findings, computational modeling of the striatal network has predicted that under healthy conditions dMSNs should receive more total input than iMSNs. To test this prediction, we analyzed in vivo whole cell recordings from dMSNs and iMSNs in healthy and dopamine-depleted (6OHDA) anaesthetized mice. By comparing their membrane potential fluctuations, we found that dMSNs exhibited considerably larger membrane potential fluctuations over a wide frequency range. Furthermore, by comparing the spike-triggered average membrane potentials, we found that dMSNs depolarized toward the spike threshold significantly faster than iMSNs did. Together, these findings (in particular the STA analysis) corroborate the theoretical prediction that direct-pathway MSNs receive stronger total input than indirect-pathway neurons. Finally, we found that dopamine-depleted mice exhibited no difference between the membrane potential fluctuations of dMSNs and iMSNs. These data provide new insights into the question of how the lack of dopamine may lead to behavioral deficits associated with Parkinson’s disease. NEW & NOTEWORTHY The direct and indirect pathways of the basal ganglia originate from the D1- and D2-type dopamine receptor expressing medium spiny neurons (dMSNs and iMSNs). Theoretical results have predicted that dMSNs should receive stronger synaptic input than iMSNs. Using in vivo intracellular membrane potential data, we provide evidence that dMSNs indeed receive stronger input than iMSNs, as has been predicted by the computational model.


2021 ◽  
Vol 12 ◽  
Author(s):  
Andrea Mancini ◽  
Veronica Ghiglieri ◽  
Lucilla Parnetti ◽  
Paolo Calabresi ◽  
Massimiliano Di Filippo

The basal ganglia network is represented by an interconnected group of subcortical nuclei traditionally thought to play a crucial role in motor learning and movement execution. During the last decades, knowledge about basal ganglia physiology significantly evolved and this network is now considered as a key regulator of important cognitive and emotional processes. Accordingly, the disruption of basal ganglia network dynamics represents a crucial pathogenic factor in many neurological and psychiatric disorders. The striatum is the input station of the circuit. Thanks to the synaptic properties of striatal medium spiny neurons (MSNs) and their ability to express synaptic plasticity, the striatum exerts a fundamental integrative and filtering role in the basal ganglia network, influencing the functional output of the whole circuit. Although it is currently established that the immune system is able to regulate neuronal transmission and plasticity in specific cortical areas, the role played by immune molecules and immune/glial cells in the modulation of intra-striatal connections and basal ganglia activity still needs to be clarified. In this manuscript, we review the available evidence of immune-based regulation of synaptic activity in the striatum, also discussing how an abnormal immune activation in this region could be involved in the pathogenesis of inflammatory and degenerative central nervous system (CNS) diseases.


2020 ◽  
Author(s):  
J. Alegre-Cortés ◽  
M. Sáez ◽  
R. Montanari ◽  
R. Reig

AbstractBehavioural studies differentiate the rodent dorsal striatum (DS) into lateral and medial regions; however, anatomical evidence suggests that it is a unified structure. To understand striatal dynamics and basal ganglia functions, it is essential to clarify the circuitry that supports this behavioural-based segregation. Here, we show that the mouse DS is made of two non-overlapping functional circuits divided by a boundary. Combining in vivo optopatch-clamp and extracellular recordings of spontaneous and evoked sensory activity, we demonstrate different coupling of lateral and medial striatum to the cortex together with an independent integration of the spontaneous activity, due to particular corticostriatal connectivity and local attributes of each region. Additionally, we show differences in slow and fast oscillations and in the electrophysiological properties between striatonigral and striatopallidal neurons. In summary, these results demonstrate that the rodent DS is segregated in two neuronal circuits, in homology with the caudate and putamen nuclei of primates.


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