Neuroscience 2001 Abstract
| Presentation Number: | 71.34 |
|---|---|
| Abstract Title: | Effects of oral Δ-9-tetrahydrocannabinol (THC) on reflexive and voluntary saccades in humans. |
| Authors: |
Ploner, C. J.*1
; Tschirch, A.1
; Ostendorf, F.1
; Sporkert, F.2
; Pragst, F.2
; Stadelmann, A.3
1Klinik für Neurologie, Charité, Berlin, Germany 2Institut für Rechtsmedizin, Charité, Berlin, Germany 3Klinik für Psychiatrie, Charité, Berlin, Germany |
| Primary Theme and Topics |
Motor Systems - Oculomotor -- Saccadic eye movement |
| Secondary Theme and Topics | Cognition and Behavior<br />- Human Cognition and Behavior<br />-- Other higher functions |
| Session: |
71. Oculomotor: saccades Poster |
| Presentation Time: | Sunday, November 11, 2001 9:00 AM-10:00 AM |
| Location: | Exhibit Hall LL-7 |
| Keywords: | CANNABINOIDS, EYE MOVEMENT, PREFRONTAL CORTEX, WORKING MEMORY |
The physiological and anatomical underpinnings of the acute cognitive effects of cannbinoids in humans are poorly understood. Here, we investigated acute cerebral effects of THC in 12 healthy human volunteers. Subjects received 10 mg oral Δ-9-THC (Marinol) and were tested with saccadic paradigms during a period of peak subjective intoxication and peak plasma levels of THC two hours after intake.
Compared to baseline testing, no change in accuracy of reflexive saccades was found. However, memory-guided saccades showed a significant increase in variable tageting errors (gain variability: 0.24 vs. 0.19, p = 0.02) and a significant increase in erroneous anticipatory saccades during the memory delay (12.0% vs. 4.3%, p = 0.01). Likewise, a significant increase in antisaccade errors was found (13.2% vs 5.8%, p = 0.008). For all types of saccades, changes in latencies were subtle. Saccadic peak velocities were unaffected by THC.
We conclude that oral Δ-9-THC mainly acts on prefrontal components of the saccadic system, while parietal and brainstem components are not significantly affected. These effects are consistent with the known cerebral distribution of CB1-receptors and allow for the hypothesis that the endogenous cannabinoidergic system may be able to modulate spatial working memory and reflexive saccade inhibition in humans.
Compared to baseline testing, no change in accuracy of reflexive saccades was found. However, memory-guided saccades showed a significant increase in variable tageting errors (gain variability: 0.24 vs. 0.19, p = 0.02) and a significant increase in erroneous anticipatory saccades during the memory delay (12.0% vs. 4.3%, p = 0.01). Likewise, a significant increase in antisaccade errors was found (13.2% vs 5.8%, p = 0.008). For all types of saccades, changes in latencies were subtle. Saccadic peak velocities were unaffected by THC.
We conclude that oral Δ-9-THC mainly acts on prefrontal components of the saccadic system, while parietal and brainstem components are not significantly affected. These effects are consistent with the known cerebral distribution of CB1-receptors and allow for the hypothesis that the endogenous cannabinoidergic system may be able to modulate spatial working memory and reflexive saccade inhibition in humans.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2001 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2001. Online.
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