Tags

Type your tag names separated by a space and hit enter

Ketamine and fMRI BOLD signal: distinguishing between effects mediated by change in blood flow versus change in cognitive state.
Hum Brain Mapp 2003; 18(2):135-45HB

Abstract

No human fMRI studies have examined ketamine effects on the BOLD signal change associated with cognitive task performance. We wished to distinguish between effects on 1) cerebral blood flow, with resultant change in BOLD signal; and 2) cognition and neural mechanisms underlying BOLD signal change associated with task performance. Eight right-handed men (mean age 28.75 years) received ketamine or saline i.v. in a randomized, double-blind manner (bolus 0.23 mg/kg; 0.5 mg/kg over 45 min to a maximum 1 hr). Subjects viewed 10 alternating 30-sec blocks of faces with neutral expressions and a fixation cross and discriminated gender of faces. Gradient echo echoplanar images were acquired on a GE Signa 1.5 T Neurovascular system. One hundred T2-weighted images depicting BOLD contrast were acquired over 5 min (for each task) at each of 14 near-axial noncontiguous 7-mm thick planes. Ketamine significantly increased dissociative phenomena and negative symptoms, but did not affect performance of the gender discrimination task. Significant BOLD signal change was demonstrated predominantly in occipitotemporal cortex with both ketamine and placebo. Only two clusters in middle occipital gyrus (BA 18) and precentral gyrus (BA 4) showed significantly decreased BOLD signal change during ketamine compared to placebo. BOLD signal change was not significantly greater in any region during ketamine. Our findings demonstrate subtle rather than major differences between the effects of ketamine and placebo upon the BOLD signal change during perception of face-non face contrast. We suggest that they represent task-dependent effects of the drug/placebo, rather than task-independent effects of the drug per se, and indicate that the effects of ketamine on cerebral blood flow are predominantly focal and task-dependent, rather than global and task-independent.

Authors+Show Affiliations

Institute of Psychiatry, London, United Kingdom. kathryn.m.abel@man.ac.ukNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Journal Article
Randomized Controlled Trial

Language

eng

PubMed ID

12518293

Citation

Abel, Kathryn M., et al. "Ketamine and fMRI BOLD Signal: Distinguishing Between Effects Mediated By Change in Blood Flow Versus Change in Cognitive State." Human Brain Mapping, vol. 18, no. 2, 2003, pp. 135-45.
Abel KM, Allin MP, Kucharska-Pietura K, et al. Ketamine and fMRI BOLD signal: distinguishing between effects mediated by change in blood flow versus change in cognitive state. Hum Brain Mapp. 2003;18(2):135-45.
Abel, K. M., Allin, M. P., Kucharska-Pietura, K., Andrew, C., Williams, S., David, A. S., & Phillips, M. L. (2003). Ketamine and fMRI BOLD signal: distinguishing between effects mediated by change in blood flow versus change in cognitive state. Human Brain Mapping, 18(2), pp. 135-45.
Abel KM, et al. Ketamine and fMRI BOLD Signal: Distinguishing Between Effects Mediated By Change in Blood Flow Versus Change in Cognitive State. Hum Brain Mapp. 2003;18(2):135-45. PubMed PMID: 12518293.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Ketamine and fMRI BOLD signal: distinguishing between effects mediated by change in blood flow versus change in cognitive state. AU - Abel,Kathryn M, AU - Allin,Matthew P G, AU - Kucharska-Pietura,Katarzyna, AU - Andrew,Chris, AU - Williams,Steve, AU - David,Anthony S, AU - Phillips,Mary L, PY - 2003/1/9/pubmed PY - 2003/4/10/medline PY - 2003/1/9/entrez SP - 135 EP - 45 JF - Human brain mapping JO - Hum Brain Mapp VL - 18 IS - 2 N2 - No human fMRI studies have examined ketamine effects on the BOLD signal change associated with cognitive task performance. We wished to distinguish between effects on 1) cerebral blood flow, with resultant change in BOLD signal; and 2) cognition and neural mechanisms underlying BOLD signal change associated with task performance. Eight right-handed men (mean age 28.75 years) received ketamine or saline i.v. in a randomized, double-blind manner (bolus 0.23 mg/kg; 0.5 mg/kg over 45 min to a maximum 1 hr). Subjects viewed 10 alternating 30-sec blocks of faces with neutral expressions and a fixation cross and discriminated gender of faces. Gradient echo echoplanar images were acquired on a GE Signa 1.5 T Neurovascular system. One hundred T2-weighted images depicting BOLD contrast were acquired over 5 min (for each task) at each of 14 near-axial noncontiguous 7-mm thick planes. Ketamine significantly increased dissociative phenomena and negative symptoms, but did not affect performance of the gender discrimination task. Significant BOLD signal change was demonstrated predominantly in occipitotemporal cortex with both ketamine and placebo. Only two clusters in middle occipital gyrus (BA 18) and precentral gyrus (BA 4) showed significantly decreased BOLD signal change during ketamine compared to placebo. BOLD signal change was not significantly greater in any region during ketamine. Our findings demonstrate subtle rather than major differences between the effects of ketamine and placebo upon the BOLD signal change during perception of face-non face contrast. We suggest that they represent task-dependent effects of the drug/placebo, rather than task-independent effects of the drug per se, and indicate that the effects of ketamine on cerebral blood flow are predominantly focal and task-dependent, rather than global and task-independent. SN - 1065-9471 UR - https://www.unboundmedicine.com/medline/citation/12518293/Ketamine_and_fMRI_BOLD_signal:_distinguishing_between_effects_mediated_by_change_in_blood_flow_versus_change_in_cognitive_state_ L2 - https://doi.org/10.1002/hbm.10064 DB - PRIME DP - Unbound Medicine ER -