scholarly journals Covert spatial selection in primate basal ganglia

2018 ◽  
Author(s):  
Fabrice Arcizet ◽  
Richard J. Krauzlis

AbstractThe basal ganglia are important for action selection. They are also implicated in perceptual and cognitive functions that seem far removed from motor control. Here, we tested whether the role of the basal ganglia in selection extends to non-motor aspects of behavior by recording neuronal activity in the caudate nucleus while animals performed a covert spatial attention task. We found that caudate neurons strongly select the spatial location of the relevant stimulus throughout the task even in the absence of any overt action. This spatially selective activity was dependent on task and visual conditions, and could be dissociated from goal-directed actions. Caudate activity was also sufficient to correctly identify every epoch in the covert attention task. These results provide a novel perspective on mechanisms of attention by demonstrating that the basal ganglia are involved in spatial selection and tracking of behavioral states even in the absence of overt orienting movements.

Author(s):  
Adriane Guillaumin ◽  
Gian Pietro Serra ◽  
François Georges ◽  
Åsa Wallén-Mackenzie

AbstractThe subthalamic nucleus is important achieve intended movements. Loss of its normal function is strongly associated with several movement disorders. Classical basal ganglia models postulate that two parallel pathways, the direct and indirect pathways, exert opposing control over movement, with the subthalamic nucleus part of the indirect pathway through which competing motor programs are prevented. The subthalamic nucleus is regulated by both inhibitory and excitatory projections but experimental evidence for its role in motor control has remained sparse. The objective here was to tease out the selective impact of the subthalamic nucleus on several motor parameters required to achieve intended movement, including locomotion, balance and motor coordination. Optogenetic excitation and inhibition using both bilateral and unilateral stimulations of the subthalamic nucleus were implemented in freely-moving mice. The results demonstrate that selective optogenetic inhibition of the subthalamic nucleus enhances locomotion while its excitation reduces locomotion. These findings lend experimental support to basal ganglia models in terms of locomotion. However, further analysis of subthalamic nucleus excitation revealed grooming and disturbed gait. Selective excitation also caused reduced motor coordination, independent of grooming, in advanced motor tasks. This study contributes experimental evidence for a regulatory role of the subthalamic nucleus in motor control.HighlightsBilateral optogenetic excitation of the subthalamic nucleus in freely-moving mice reduces forward locomotion while optogenetic inhibition leads to its increase.Unilateral optogenetic excitation and inhibition of the subthalamic nucleus cause opposite rotational behavior.Bilateral optogenetic excitation, but not inhibition, of the subthalamic nucleus induces jumping and self-grooming behavior.Engaged in advanced motor tasks, bilateral optogenetic excitation causes mice to lose motor coordination.The results provide experimental support for predictions by the basal ganglia motor model on the role of the subthalamic nucleus in locomotion, and identifies a causal role for the subthalamic nucleus in self-grooming.


2002 ◽  
Vol 87 (6) ◽  
pp. 3090-3101 ◽  
Author(s):  
Takafumi Minamimoto ◽  
Minoru Kimura

The centre médian-parafascicular (CM-Pf) complex is located at the posterior intralaminar nuclei of the thalamus and forms part of the nonspecific thalamocortical projection system and the internal circuit of the basal ganglia. However, the functional roles of this complex remain to be fully elucidated. Here we have examined whether the CM-Pf complex is involved in the process of covert attention. We trained two macaque monkeys to perform a task in which a visual target stimulus for button release appeared at either the same location as the preceding visual instruction cue (a “validly cued target”) or a location on the opposite side (an “invalidly cued target”). Reaction times (RTs) to a validly cued target were significantly shorter than those to an invalidly cued target, leading to a “validity effect” of about 20 ms. We recorded the activity of 97 neurons in the CM-Pf while the monkeys performed the attention task with the hand that was contralateral to the neuronal recording. Seventy CM-Pf neurons showed task-related activity after the appearance of either the instruction cue or the target stimulus: 33 neurons responded with a prominent short-latency facilitation (SLF), whereas 37 responded with a short-latency suppression followed by a long-latency facilitation (LLF). Most of the SLF neurons responded preferentially to a cue appearing on the contralateral side (76%) and to an invalidly cued target appearing on the contralateral side (61%). In contrast, LLF neurons showed a short-latency suppression after the cue stimulus, regardless of whether the cue appeared on the contra- or ipsilateral side (84%). Inactivating the CM-Pf complex by local injection (1 μl) of the GABAA receptor agonist muscimol (1–5 μg/μl) resulted in a significant increase in the RT to a validly cued target presented on the contra- but not the ipsilateral side. In contrast, inactivating the CM-Pf complex did not affect RTs to invalidly cued targets on either the contra- or the ipsilateral side. Thus the validity effect was abolished only on the contralateral side. We conclude that the CM-Pf complex plays a specific and essential role in the process of attentional orienting to external events occurring on the contralateral side, probably through the projection of primary outputs to the striatum, which is involved in the action-selection mechanisms of the basal ganglia.


Author(s):  
Lijuan Hou ◽  
Jimin Zhang ◽  
Xinwei Wang ◽  
Fei Gong ◽  
Xue Sun
Keyword(s):  

2018 ◽  
Author(s):  
Danqian Liu ◽  
Chenyan Ma ◽  
Weitong Zheng ◽  
Yuanyuan Yao ◽  
Yang Dan

AbstractFrom invertebrates to humans, a defining feature of sleep is behavioral immobility(Campbell and Tobler, 1984; Hendricks et al., 2000; Shaw et al., 2000). In mammals, diminished electromyographic (EMG) activity is a major criterion for both rapid eye movement (REM) and non-REM (NREM) sleep. However, the relationship between sleep and motor control at the neuronal level remains poorly understood. Here we show that regions of the basal ganglia long known to be essential for motor suppression also play a key role in sleep generation. Optogenetic or chemogenetic activation of GABAergic neurons in mouse substantia nigra pars reticulata (SNr) strongly increased both REM and NREM sleep, whereas their inactivation suppressed sleep and increased wakefulness. Analysis of natural home-cage behavior showed that mice transition sequentially through several behavioral states: locomotion, non-locomotor movement, quiet wakefulness, and sleep. Activation/inactivation of SNr neurons promoted/suppressed sleep by biasing the direction of progression through the natural behavioral sequence. Virus-mediated circuit tracing showed that SNr GABAergic neurons project to multiple wake-promoting monoaminergic cell groups in addition to the thalamus and mesencephalic locomotor region, and activating each projection promoted sleep. Within the thalamus, direct optogenetic inactivation of glutamatergic neurons is sufficient to enhance sleep, but the effect is largely restricted to the regions receiving SNr projection. Furthermore, a major source of excitatory inputs to the SNr is the subthalamic nucleus (STN), and activation of neurotensin-expressing glutamatergic neurons in the STN also promoted sleep. Together, these results demonstrate a key role of the STN-SNr basal ganglia pathway in sleep generation and reveal a novel circuit mechanism linking sleep and motor control.


2003 ◽  
Vol 10 (1-2) ◽  
pp. 107-120 ◽  
Author(s):  
Henk J. Groenewegen

This paper briefly reviews the functional anatomy of the basal ganglia and their relationships with the thalamocortical system. The basal ganglia, including the striatum, pallidum, subthalamic nucleus, and substantia nigra, are involved in a number of parallel, functionally segregated cortical-subcortical circuits. These circuits support a wide range of sensorimotor, cognitive and emotional-motivational brain functions. A main role of the basal ganglia is the learning and selection of the most appropriate motor or behavioral programs. The internal functional organization of the basal ganglia is very well suited for such selection mechanisms, both in development and in adulthood. The question of whether clumsiness may be, at least in part, attributed to dysfunction of the basal ganglia is discussed in the context of the differential, complementary, or interactive roles of the basal ganglia and the cerebellum in the development of motor control.


2005 ◽  
Vol 16 (4) ◽  
pp. 235-242 ◽  
Author(s):  
Astrid von Bueren Jarchow ◽  
Bogdan P. Radanov ◽  
Lutz Jäncke

Abstract: The aim of the present study was to examine to what extent chronic pain has an impact on various attentional processes. To measure these attention processes a set of experimental standard tests of the “Testbatterie zur Aufmerksamkeitsprüfung” (TAP), a neuropsychological battery testing different levels of attention, were used: alertness, divided attention, covert attention, vigilance, visual search, and Go-NoGo tasks. 24 chronic outpatients and 24 well-matched healthy control subjects were tested. The control subjects were matched for age, gender, and education. The group of chronic pain patients exhibited marked deficiencies in all attentional functions except for the divided attention task. Thus, the data supports the notion that chronic pain negatively influences attention because pain patients` attention is strongly captivated by the internal pain stimuli. Only the more demanding divided attention task has the capability to distract the focus of attention to the pain stimuli. Therefore, the pain patients are capable of performing within normal limits. Based on these findings chronic pain patients' attentional deficits should be appropriately evaluated and considered for insurance and work related matters. The effect of a successful distraction away from the pain in the divided attention task can also open new therapeutic aspects.


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