scholarly journals Cortically Activated Interneurons Shape Spatial Aspects of Cortico-Accumbens Processing

2009 ◽  
Vol 101 (4) ◽  
pp. 1876-1882 ◽  
Author(s):  
Aaron J. Gruber ◽  
Elizabeth M. Powell ◽  
Patricio O'Donnell
Keyword(s):  
Basal Ganglia ◽  
Projection Neurons ◽  
Behavioral Outcome ◽  
Excitatory Response ◽  
Local Inhibition ◽  
Naturally Occurring ◽  
Parallel Loops ◽  
Winner Take All ◽  
Take All ◽  
Stimulation Of

Basal ganglia circuits are organized as parallel loops that have been proposed to compete in a winner-take-all fashion to determine the appropriate behavioral outcome. However, limited experimental support for strong lateral inhibition mechanisms within striatal regions questions this model. Here, stimulation of the prefrontal cortex (PFC) using naturally occurring bursty patterns inhibited firing in most nucleus accumbens (NA) projection neurons. When an excitatory response was observed for one stimulation site, neighboring PFC sites evoked inhibition in the same neuron. Furthermore, PFC stimulation activated interneurons, and PFC-evoked inhibition was blocked by GABAA antagonists in corticoaccumbens slice preparations. Thus bursting PFC activity recruits local inhibition in the NA, shaping responses of projection neurons with a topographical arrangement that allows inhibition among parallel corticoaccumbens channels. The data indicate a high order of information processing within striatal circuits that should be considered in models of basal ganglia function and disease.

scholarly journals Motor thalamus supports striatum-driven reinforcement

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Arnaud L Lalive ◽  
Anthony D Lien ◽  
Thomas K Roseberry ◽  
Christopher H Donahue ◽  
Anatol C Kreitzer
Keyword(s):  
Synaptic Plasticity ◽  
Basal Ganglia ◽  
Substantia Nigra ◽  
Projection Neurons ◽  
Direct Pathway ◽  
Substantia Nigra Reticulata ◽  
Motor Thalamus ◽  
Self Stimulation ◽  
Stimulation Of

Reinforcement has long been thought to require striatal synaptic plasticity. Indeed, direct striatal manipulations such as self-stimulation of direct-pathway projection neurons (dMSNs) are sufficient to induce reinforcement within minutes. However, it’s unclear what role, if any, is played by downstream circuitry. Here, we used dMSN self-stimulation in mice as a model for striatum-driven reinforcement and mapped the underlying circuitry across multiple basal ganglia nuclei and output targets. We found that mimicking the effects of dMSN activation on downstream circuitry, through optogenetic suppression of basal ganglia output nucleus substantia nigra reticulata (SNr) or activation of SNr targets in the brainstem or thalamus, was also sufficient to drive rapid reinforcement. Remarkably, silencing motor thalamus—but not other selected targets of SNr—was the only manipulation that reduced dMSN-driven reinforcement. Together, these results point to an unexpected role for basal ganglia output to motor thalamus in striatum-driven reinforcement.

scholarly journals Basal Ganglia Responses to Electrical Stimulation of the Posterior Hypothalamic Nucleus

2021 ◽  
Author(s):  
Calvin K Young ◽  
Brian H Bland
Keyword(s):  
Basal Ganglia ◽  
Neural Substrates ◽  
Hypothalamic Nucleus ◽  
High Frequency Stimulation ◽  
Excitatory Response ◽  
Posterior Hypothalamic Nucleus ◽  
Frequency Stimulation ◽  
Urethane Anaesthesia ◽  
The Impact ◽  
Stimulation Of

Electrical or chemical stimulation of the posterior hypothalamic nucleus (PH) elicits highly adaptive locomotion, demonstrating both evidence of flexibility and variety in exhibited motor behaviours. However, the neural substrates of PH stimulation elicited behavioural changes are poorly understood. The basal ganglia are postulated to be critically involved in the process of action selection in conjunction with thalamo-cortical systems. The present study examines changes in basal ganglia activities in response to the high-frequency stimulation of the PH. Under urethane anaesthesia, ensemble and single-unit recordings were obtained from the striatum (STR), globus pallidus externa (GPe), entopeduncular nucleus (EP), subthalamic nucleus (STN) and the substantia nigra pars reticulata (SNr). Upon PH stimulation, increases in firing rates were observed in the STR, GPe, and STN, a decrease was observed in the SNr and no changes were seen in the EP. The increase in spike rate in the STR and GPe was dependent on the stimulation intensity but not duration. Despite the differences in the direction of firing changes during PH stimulation, all examined areas including those not part of the basal ganglia demonstrated an elevated spiking rate upon stimulus train termination. Taking into account the known anatomical connections between the PH and the basal ganglia, it is hypothesized responses seen during PH stimulus trains are mediated through thalamic and cortical relays whereas the overall post-stimulus excitatory response is related to the impact of the PH on brainstem arousal systems.

scholarly journals Opposing regulation of short-term memory by basal ganglia direct and indirect pathways that are coactive during behavior

2021 ◽  
Author(s):  
Yingjun Tang ◽  
Hongjiang Yang ◽  
Xia Chen ◽  
Zhouzhou Zhang ◽  
Xiao Yao ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Short Term Memory ◽  
Quantitative Difference ◽  
Projection Neurons ◽  
Decision Variable ◽  
Similar Response ◽  
Short Term ◽  
Population Activity ◽  
Term Memory ◽  
Stimulation Of

The basal ganglia direct and indirect pathways are viewed to mediate opposing functions in movement. However, this classic model is challenged by recent findings that both pathways are coactive during behavior. We examined the roles of direct (dSPNs) and indirect (iSPNs) pathway spiny projection neurons in a decision-making task with a short-term memory (STM) component. Optogenetic stimulation of cortical-input-defined dSPNs and iSPNs during STM oppositely biased upcoming licking choice, without affecting licking execution. Optogenetically identified dSPNs and iSPNs showed similar response patterns, although with quantitative difference in spatiotemporal organization. To understand how coactive dSPNs and iSPNs play opposing roles, we recorded population activity in frontal cortex and the basal ganglia output nucleus SNr. Stimulation of dSPNs and iSPNs bidirectionally regulated cortical decision variable through the differential modulation of SNr ramping activity. These results reconcile different views by demonstrating that coactive dSPNs and iSPNs precisely shape cortical activity in a push-pull balance.

scholarly journals Optogenetic stimulation of medial amygdala GABA neurons with kinetically different channelrhodopsin variants yield opposite behavioral outcomes

2021 ◽  
Author(s):  
Aiste Baleisyte ◽  
Ralf Schneggenburger ◽  
Olexiy Kochubey
Keyword(s):  
Behavioral Outcomes ◽  
Inhibitory Neurons ◽  
Projection Neurons ◽  
Medial Amygdala ◽  
Optogenetic Stimulation ◽  
Gaba Neurons ◽  
Local Inhibition ◽  
Neuron Populations ◽  
Stimulation Of

Optogenetic manipulation of genetically-specified neuron populations has become a key tool in circuit neuroscience. The medial amygdala (MeA) receives pheromone information about conspecifics and has crucial functions in social behaviors; interestingly, this amygdalar structure contains a majority of GABAergic projection neurons. A previous study showed that optogenetic activation of MeA GABA neurons with channelrhodopsin-2H134R (ChR2) strongly enhanced inter-male aggression (Hong et al. 2014, Cell). When we attempted to reproduce these findings, accidentally using a faster channelrhodopsin variant (channelrhodopsin-2H134R,E123T or ChETA), we found the opposite results. We therefore systematically compared the behavioral outcome of optogenetic stimulation of MeApd GABA neurons with ChETA versus ChR2, employing two widely used AAV serotypes. This revealed that optogenetic stimulation with ChETA suppressed aggression, whereas optogenetic stimulation with ChR2 increased aggression. Recordings of membrane potential changes following optogenetic stimulation with ChETA versus ChR2 revealed larger plateau depolarizations, smaller action potential amplitudes, and larger local inhibition of neighboring inhibitory neurons with ChR2 as compared to ChETA. Our study shows that channelrhodopsin variants have to be chosen with care for in-vivo optogenetic experiments. Furthermore, the role of MeApd GABA neurons in aggression control should be re-evaluated.

Diencephalic Locomotor Region in the Lamprey—Afferents and Efferent Control

2008 ◽  
Vol 100 (3) ◽  
pp. 1343-1353 ◽  
Author(s):  
Ariane Ménard ◽  
Sten Grillner
Keyword(s):  
Basal Ganglia ◽  
Brain Stem ◽  
Ventral Root ◽  
The Body ◽  
Tonic Inhibition ◽  
Projection Neurons ◽  
Spinal Level ◽  
Double Labeling ◽  
The Brain ◽  
Stimulation Of

In vertebrates, locomotion can be initiated by stimulation of the diencephalic locomotor region (DLR). Little is known of the different forebrain regions that provide input to the neurons in DLR. In the lamprey, it had been shown previously that DLR provides monosynaptic input to reticulospinal neurons, which in turn elicit rhythmic ventral root activity at the spinal level. To show that actual locomotor movements are produced from DLR, we use a semi-intact preparation in which the brain stem is exposed and the head fixed, while the body is left to generate actual swimming movements. DLR stimulation induced symmetric locomotor movements with an undulatory wave transmitted along the body. To explore if DLR is under tonic GABAergic input under resting conditions, as in mammals, GABAergic antagonists and agonists were locally administered into DLR. Injections of GABA agonists inhibited locomotion, whereas GABA antagonists facilitated the induction of locomotion. These findings suggest that GABAergic projections provide tonic inhibition that once turned off can release locomotion. Double-labeling experiments were carried out to identify GABAergic projections to the DLR. Populations of GABAergic projection neurons to DLR originated in the caudoventral portion of the medial pallium, the lateral and dorsal pallium, and the striatal area. These different GABAergic projection neurons, which also project to other brain stem motor centers, may represent the basal ganglia output to DLR. Moreover, electrical stimulation of striatum induced long-lasting plateau potentials in reticulospinal cells and associated locomotor episodes dependent on DLR being intact, suggesting that striatum may act via the basal ganglia output identified here.

Interest Groups and Elections

2019 ◽  
pp. 339-357
Author(s):  
Jeffrey M. Berry
Keyword(s):  
Political Parties ◽  
Interest Groups ◽  
Campaign Finance ◽  
Organizational Forms ◽  
Super Pacs ◽  
New Organizational Forms ◽  
Winner Take All ◽  
The Impact ◽  
Take All

The relationships between interest groups, political parties, and elections have always been dynamic, but in recent years change has accelerated in ways that have favored some interests over others. This chapter considers these developments as the result of a variety of factors, the most critical of which are the growth of polarization, a new legal landscape for campaign finance, and new organizational forms. The chapter goes on to suggest, that as bipartisanship has ebbed, elections have become winner-take-all affairs and interest groups are pushed to choose sides. The chapter further suggests that the rise of super PACs is especially notable as wealthy individuals have become increasingly important, single sources of campaign money, supplanting in part traditional interest groups, especially conventional PACs. It concludes that even as sums spent by super PACs and other interest groups have skyrocketed, the impact of their direct spending on persuading voters remains uncertain.

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