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Amphetamine's dose-dependent effects on dorsolateral striatum sensorimotor neuron firing
Sisi Ma1, Anthony P Pawlak, Jeiwon Cho
1Department of Psychology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08854, USA. sisima@rci.rutgers.edu
Behavioural Brain Research
|February 12, 2013
Summary
Amphetamine alters movement by changing neuron activity in the dorsolateral striatum (DLS). Lower doses increase movement, while high doses cause stereotypy, impacting sensorimotor processing.
Area of Science:
- Neuroscience
- Pharmacology
- Motor Control
Background:
- Amphetamine alters dopamine and serotonin activity, influencing motor behavior.
- The dorsolateral striatum (DLS) is implicated in motor control and affected by amphetamine.
- Medium spiny neurons in the DLS are hypothesized to mediate amphetamine's motor effects.
Purpose of the Study:
- To investigate how DLS neural activity relates to amphetamine-induced motor changes.
- To characterize the dose-dependent effects of amphetamine on DLS neuron firing rates.
- To explore the relationship between neural firing patterns and specific movement parameters.
Main Methods:
- Recorded vertical head movement neuron activity in the DLS before and after amphetamine administration.
- Tracked head movements to define parameters like distance, duration, and direction.
- Analyzed changes in neuron firing rates (FR) in relation to amphetamine dose and pre-injection FR.
Main Results:
- Amphetamine induced an inverted U-shaped dose-response curve for head movements.
- Lower amphetamine doses increased long movements, while higher doses induced stereotypy.
- Amphetamine modulated DLS neuron FRs in an inverted U-shaped manner, increasing slow-firing neurons and decreasing fast-firing neurons.
Conclusions:
- DLS neural activity modulation by amphetamine may disrupt sensorimotor processing.
- Altered DLS firing patterns, particularly increased slow-neuron activity, could enhance premotor area excitability.
- This mechanism may contribute to amphetamine's effects on movement initiation and execution.
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