Evaluating the Roles of Dopamine 2 and Nicotinic Receptors in Altered Response Inhibition and Attention Caused by Circadian Disruption

Tran, Chi T.; Balachandran, Rekha C.; Sieg, Megan L.

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Description

Title

Evaluating the Roles of Dopamine 2 and Nicotinic Receptors in Altered Response Inhibition and Attention Caused by Circadian Disruption

Author(s)

• Tran, Chi T.
• Balachandran, Rekha C.
• Sieg, Megan L.

Contributor(s)

Eubig, Paul A.

Issue Date

2018-04

Keyword(s)

• Comparative Biosciences
• Neuroscience Program
• Circadian rhythm
• attention
• response inhibition

Abstract

Circadian rhythms are endogenous rhythms governing behavior and physiology. Common sources of circadian disruption (CD) in human populations include working beyond the regular hours of ‘9 to 5’ (shift work) and untimely exposure to light (light-at- night, LAN). Our study investigated the effect of 2 models of CD on response inhibition (RI), which has previously been unaddressed, and attention using a 5-choice serial reaction time behavior task (5-CSRTT). We maintained adult Long-Evans rats of both sexes on a 12h:12h light: dark cycle and were tested under one of 3 light conditions: LAN, light phase testing (shift work model), and control. Our hypothesis that rats tested under the 2 models of CD would have reduced RI and be less attentive than controls was confirmed. A possible mechanism to explain our findings lies in acetylcholine (ACh) signaling, which governs optimal attentional performance and circadian rhythms, and dopamine (DA) signaling, which modulates impulsive behavior. In the prefrontal cortex, ACh modulates DA release. To investigate the role of dopamine 2 receptors (D2Rs) in our behavioral findings, we used nicotine as a cholinergic agonist and eticlopride as a D2R antagonist to study how the drugs individually and in combination altered response inhibition and attention. Our hypothesis that nicotine would increase and eticlopride would decrease premature responding and in combination, eticlopride would reduce the effects of nicotine was confirmed.

Type of Resource

image

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http://hdl.handle.net/2142/99993

Copyright and License Information

• Copyright 2018 Chi T. Tran
• Copyright 2018 Rekha C. Balachandran
• Copyright 2018 Megan L. Sieg

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