Mechanisms of Action Selection and Timing in Substantia Nigra Neurons

A hypothesized voluntary action selection mechanism for the SNc and LC has been proposed that is based on the apparent ability of ferritin and neuromelanin to support electron transport in those tissues. (Rourk 2018; Rourk 2019). A state machine model is presented in this paper that provides an explanation for neural correlates of that hypothesized voluntary action selection mechanism to the human experience of consciousness.

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Cortical mechanisms of action selection: the affordance competition hypothesis

Modelling Natural Action Selection ◽

10.1017/cbo9780511731525.015 ◽

2011 ◽

pp. 208-238 ◽

Cited By ~ 2

Author(s):

Paul Cisek

Keyword(s):

Action Selection ◽

Mechanisms Of Action ◽

Competition Hypothesis

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Mechanisms of Action of Substantia Nigra and Adrenal Medulla Grafts

Progress in Parkinson Research ◽

10.1007/978-1-4613-0759-4_25 ◽

1988 ◽

pp. 197-204

Author(s):

William J. Freed ◽

Jill B. Becker

Keyword(s):

Substantia Nigra ◽

Adrenal Medulla ◽

Mechanisms Of Action

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Mechanisms of Action Selection: Introduction to the Special Issue

Adaptive Behavior ◽

10.1177/1059712306076247 ◽

2007 ◽

Vol 15 (1) ◽

pp. 5-8 ◽

Cited By ~ 10

Author(s):

Joanna J. Bryson

Keyword(s):

Action Selection ◽

Mechanisms Of Action ◽

Special Issue

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Unilateral optogenetic inhibition and excitation of basal ganglia output show opposing effects on directional lick choices and movement initiation in mice

10.1101/360818 ◽

2018 ◽

Author(s):

Arthur E. Morrissette ◽

Po-Han Chen ◽

Conrad Bhamani ◽

Peter Y. Borden ◽

Christian Waiblinger ◽

...

Keyword(s):

Decision Making ◽

Basal Ganglia ◽

Substantia Nigra ◽

Feedback Loop ◽

Premotor Cortex ◽

Sensory Information ◽

Action Selection ◽

Direct Test ◽

Movement Initiation ◽

Motor Thalamus

AbstractModels of basal ganglia function predict that tonic inhibitory output to motor thalamus suppresses unwanted movements, and that a decrease in such activity leads to action selection. A direct test of these outcomes of thalamic inhibition has not been performed, however. To conduct such a direct test, we utilized rapid optogenetic activation and inactivation of the GABAergic output of the substantia nigra pars reticulata (SNr) to motor thalamus in mice that were trained in a sensory cued left/right licking task. Directional licking tasks have previously been shown to depend on a thalamocortical feedback loop between ventromedial motor thalamus and antero-lateral premotor cortex (Li et al., 2015; Guo et al., 2017). In confirmation of model predictions, we found that 1s of unilateral optogenetic inhibition of GABAergic output from the SNr biased decision making towards the contralateral lick spout with ipsilaterally cued trials while leaving motor performance intact. In contrast, 1s of optogenetic excitation of SNr terminals in motor thalamus resulted in an opposite bias towards the ipsilateral direction confirming a bidirectional effect of tonic nigral output on directional decision making. In a second variant of the task we disallowed anticipatory licking and found that successful suppression of anticipatory licking was also impacted by our optogenetic manipulations in agreement with the suppressive effect of tonic nigral output. Nevertheless, direct unilateral excitation of SNr cell bodies resulted in bilateral movement suppression, suggesting that descending motor pathways from the SNr to superior colliculus also play an important role in the control of licking behavior.Significance StatementThis study provides the first evidence that basal ganglia output to motor thalamus can control decision making in left/right licking choices and suppress anticipatory movement initiation. Unilateral optogenetic inhibition or excitation of basal ganglia output via the substantia nigra resulted in opposite changes of directional lick choices and could override the sensory information on lick direction provided by a whisker stimulus. These results suggest that basal ganglia output gates activity in a thalamo-cortical feedback loop previously shown to underlie the control of forced choice directional licking behavior. The results substantiate models stating that tonic inhibition of motor thalamus from the basal ganglia directs action selection and suppresses unwanted movements.

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Immunocytochemical methodology for the localization of neuronal antigens at the ultrastructural level

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161941 ◽

1990 ◽

Vol 48 (3) ◽

pp. 876-877

Author(s):

Jorge Pecci Saavedra ◽

Mark Connaughton ◽

Juan José López ◽

Alicia Brusco

Keyword(s):

Spinal Cord ◽

Substantia Nigra ◽

Polyclonal Antibodies ◽

Ultrastructural Level ◽

Point Of View ◽

Nerve Tissue ◽

Tissue Fixation ◽

Optimal Conditions ◽

Interpeduncular Nucleus ◽

Technical Point

The use of antibodies as labels for the localization of specific molecules in the nervous systan has been extensively applied in recent years. Both monoand polyclonal antibodies or antisera have been employed. The knowledge of the organization of neuronal connectivities, gliovascular relationships, glioneuronal relationships and other features of nerve tissue has greatly increased.A number of areas of the nervous systan have been analyzed in our laboratory, including the nuclei of the raphe system, the reticular formation, interpeduncular nucleus, substantia nigra, caudate nucleus, putamen, pallidum, spinal cord, pineal gland and others.From a technical point of view, a number of variables needed to be taken into account in order to obtain reliable and reproducible results. The design of the optimal conditions of tissue fixation, embedding, sectioning, dilution of antibodies, and adaptation of Sternberger PAP technique were sane of the parameters taken into account to optimize the results. It is critical that each step of the technique be defined for each particular case.

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Diagnostic evaluation of the substantia nigra

Neuropathology and Applied Neurobiology ◽

10.1046/j.1365-2990.1996.4698046.x ◽

1996 ◽

Vol 22 (3) ◽

pp. 228-232 ◽

Cited By ~ 4

Author(s):

D. A. McRitchie ◽

G. M. Halliday ◽

R. Pamphlett

Keyword(s):

Substantia Nigra ◽

Diagnostic Evaluation

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Case Formulation and Design of Behavioral Treatment Programs

European Journal of Psychological Assessment ◽

10.1027//1015-5759.19.3.164 ◽

2003 ◽

Vol 19 (3) ◽

pp. 164-174 ◽

Cited By ~ 27

Author(s):

Stephen N. Haynes ◽

Andrew E. Williams

Keyword(s):

Functional Analysis ◽

Behavior Problems ◽

Behavioral Treatment ◽

Clinical Case ◽

Relative Magnitude ◽

Mechanisms Of Action ◽

Treatment Programs ◽

Case Formulation ◽

Functional Relations ◽

Causal Variables

Summary: We review the rationale for behavioral clinical case formulations and emphasize the role of the functional analysis in the design of individualized treatments. Standardized treatments may not be optimally effective for clients who have multiple behavior problems. These problems can affect each other in complex ways and each behavior problem can be influenced by multiple, interacting causal variables. The mechanisms of action of standardized treatments may not always address the most important causal variables for a client's behavior problems. The functional analysis integrates judgments about the client's behavior problems, important causal variables, and functional relations among variables. The functional analysis aids treatment decisions by helping the clinician estimate the relative magnitude of effect of each causal variable on the client's behavior problems, so that the most effective treatments can be selected. The parameters of, and issues associated with, a functional analysis and Functional Analytic Clinical Case Models (FACCM) are illustrated with a clinical case. The task of selecting the best treatment for a client is complicated because treatments differ in their level of specificity and have unequally weighted mechanisms of action. Further, a treatment's mechanism of action is often unknown.

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