Medications influencing central cholinergic neurotransmission affect saccadic and smooth pursuit eye movements in healthy young adults
- 348 Downloads
Acetylcholine is an important neuromodulator in the central nervous system, where it plays a significant role in central functions such as the regulation of movement.
This study investigated the pharmacological effects of over-the-counter anticholinergic medications on saccadic and smooth pursuit eye movements, in order to establish the significance of central cholinergic pathways in the control of these centrally regulated oculomotor processes.
Sixteen subjects (mean age 23 ± 3 years, 9 females) performed pro-saccadic, anti-saccadic and smooth pursuit eye movement tests, while an eye tracker collected eye movement data. Oculomotor assessments were performed pre-ingestion, 0.5 and 2 h post-ingestion of drugs with varying degrees of central anticholinergic properties. The drugs tested were promethazine, hyoscine hydrobromide, hyoscine butylbromide and placebo.
The drug intervention with stronger central anticholinergic properties, promethazine, decreased amplitude and increased velocity in the pro-saccadic task and increased duration in the anti-saccadic task. Promethazine, once again, was the only drug to decrease eye velocity in the smooth pursuit test.
The prominent effects of the stronger central anticholinergic promethazine, on saccadic and smooth pursuit eye movements, potentially conveys the significance of central cholinergic pathways in the control of these centrally regulated oculomotor processes.
KeywordsAnticholinergic Saccadic eye movement Smooth pursuit Oculomotor Neurotransmitter
- Grace PM, Stanford T, Gentgall M, Rolan PE (2010) Utility of saccadic eye movement analysis as an objective biomarker to detect the sedative interaction between opioids and sleep deprivation in opioid-naive and opioid-tolerant populations. J Psychopharmacol 24:1–10. doi: 10.1177/0269881109352704 CrossRefGoogle Scholar
- Hindmarch I, Shamsi Z, Stanley N, Fairweather DB (1999) A double-blind, placebo-controlled investigation of the effects of fexofenadine, loratadine and promethazine on cognitive and psychomotor function. Br J Clin Pharmacol 48:200–206. doi: 10.1046/j.1365-2125.1999.00993.x CrossRefPubMedPubMedCentralGoogle Scholar
- Squire L, Bloom FE, Spitzer NC, Squire LR, Berg D, du Lac S, Ghosh A (2008) Fundamental Neuroscience. Academic Press, CanadaGoogle Scholar
- Wang J (2013) Anticholinergic side effects among the elderly. APHS Pharmacy Circuit:1–4Google Scholar