59
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Cholinergic modulation of cognition: Insights from human pharmacological functional neuroimaging

      review-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Highlights

          • We review all 63 healthy human cholinergic functional neuroimaging studies to date. • General findings from fMRI and PET studies are synthesised with biological models. • Cholinergic neuromodulations are divided into sensory, attentional or memory. • Methodological issues of pharmacological functional imaging are discussed.

          Abstract

          Evidence from lesion and cortical-slice studies implicate the neocortical cholinergic system in the modulation of sensory, attentional and memory processing. In this review we consider findings from sixty-three healthy human cholinergic functional neuroimaging studies that probe interactions of cholinergic drugs with brain activation profiles, and relate these to contemporary neurobiological models. Consistent patterns that emerge are: (1) the direction of cholinergic modulation of sensory cortex activations depends upon top-down influences; (2) cholinergic hyperstimulation reduces top-down selective modulation of sensory cortices; (3) cholinergic hyperstimulation interacts with task-specific frontoparietal activations according to one of several patterns, including: suppression of parietal-mediated reorienting; decreasing ‘effort’-associated activations in prefrontal regions; and deactivation of a ‘resting-state network’ in medial cortex, with reciprocal recruitment of dorsolateral frontoparietal regions during performance-challenging conditions; (4) encoding-related activations in both neocortical and hippocampal regions are disrupted by cholinergic blockade, or enhanced with cholinergic stimulation, while the opposite profile is observed during retrieval; (5) many examples exist of an ‘inverted-U shaped’ pattern of cholinergic influences by which the direction of functional neural activation (and performance) depends upon both task (e.g. relative difficulty) and subject (e.g. age) factors. Overall, human cholinergic functional neuroimaging studies both corroborate and extend physiological accounts of cholinergic function arising from other experimental contexts, while providing mechanistic insights into cholinergic-acting drugs and their potential clinical applications.

          Related collections

          Most cited references296

          • Record: found
          • Abstract: found
          • Article: not found

          The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine.

          Despite its very potent vasodilating action in vivo, acetylcholine (ACh) does not always produce relaxation of isolated preparations of blood vessels in vitro. For example, in the helical strip of the rabbit descending thoracic aorta, the only reported response to ACh has been graded contractions, occurring at concentrations above 0.1 muM and mediated by muscarinic receptors. Recently, we observed that in a ring preparation from the rabbit thoracic aorta, ACh produced marked relaxation at concentrations lower than those required to produce contraction (confirming an earlier report by Jelliffe). In investigating this apparent discrepancy, we discovered that the loss of relaxation of ACh in the case of the strip was the result of unintentional rubbing of its intimal surface against foreign surfaces during its preparation. If care was taken to avoid rubbing of the intimal surface during preparation, the tissue, whether ring, transverse strip or helical strip, always exhibited relaxation to ACh, and the possibility was considered that rubbing of the intimal surface had removed endothelial cells. We demonstrate here that relaxation of isolated preparations of rabbit thoracic aorta and other blood vessels by ACh requires the presence of endothelial cells, and that ACh, acting on muscarinic receptors of these cells, stimulates release of a substance(s) that causes relaxation of the vascular smooth muscle. We propose that this may be one of the principal mechanisms for ACh-induced vasodilation in vivo. Preliminary reports on some aspects of the work have been reported elsewhere.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Dynamic causal modelling.

            In this paper we present an approach to the identification of nonlinear input-state-output systems. By using a bilinear approximation to the dynamics of interactions among states, the parameters of the implicit causal model reduce to three sets. These comprise (1) parameters that mediate the influence of extrinsic inputs on the states, (2) parameters that mediate intrinsic coupling among the states, and (3) [bilinear] parameters that allow the inputs to modulate that coupling. Identification proceeds in a Bayesian framework given known, deterministic inputs and the observed responses of the system. We developed this approach for the analysis of effective connectivity using experimentally designed inputs and fMRI responses. In this context, the coupling parameters correspond to effective connectivity and the bilinear parameters reflect the changes in connectivity induced by inputs. The ensuing framework allows one to characterise fMRI experiments, conceptually, as an experimental manipulation of integration among brain regions (by contextual or trial-free inputs, like time or attentional set) that is revealed using evoked responses (to perturbations or trial-bound inputs, like stimuli). As with previous analyses of effective connectivity, the focus is on experimentally induced changes in coupling (cf., psychophysiologic interactions). However, unlike previous approaches in neuroimaging, the causal model ascribes responses to designed deterministic inputs, as opposed to treating inputs as unknown and stochastic.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Anxiety and cognitive performance: attentional control theory.

              Attentional control theory is an approach to anxiety and cognition representing a major development of Eysenck and Calvo's (1992) processing efficiency theory. It is assumed that anxiety impairs efficient functioning of the goal-directed attentional system and increases the extent to which processing is influenced by the stimulus-driven attentional system. In addition to decreasing attentional control, anxiety increases attention to threat-related stimuli. Adverse effects of anxiety on processing efficiency depend on two central executive functions involving attentional control: inhibition and shifting. However, anxiety may not impair performance effectiveness (quality of performance) when it leads to the use of compensatory strategies (e.g., enhanced effort; increased use of processing resources). Directions for future research are discussed.
                Bookmark

                Author and article information

                Contributors
                Journal
                Prog Neurobiol
                Prog. Neurobiol
                Progress in Neurobiology
                Pergamon Press
                0301-0082
                1873-5118
                01 September 2011
                01 September 2011
                : 94
                : 4
                : 360-388
                Affiliations
                [a ]Wellcome Centre for Neuroimaging at UCL, University College London, 12 Queen Square, London WC1N 3BG, UK
                [b ]Department of Clinical Neuroscience, Charing Cross Hospital, Imperial College London, Fulham Palace Rd., London W6 8RF, UK
                [c ]UCL Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AR, UK
                Author notes
                [* ]Corresponding author at: Imperial College Cerebrovascular Research Unit (ICCRU), Imperial College Hospitals, Charing Cross Campus, Fulham Palace Rd., London W6 8RF, UK. Tel.: +44 02088467383. p.bentley@ 123456imperial.ac.uk
                Article
                PRONEU1119
                10.1016/j.pneurobio.2011.06.002
                3382716
                21708219
                84bda8d3-ee85-47a3-8061-95a3d7ae121c
                © 2011 Elsevier Ltd.

                This document may be redistributed and reused, subject to certain conditions.

                History
                : 24 February 2011
                : 2 June 2011
                : 7 June 2011
                Categories
                Article

                Neurosciences
                fmri, functional magnetic resonance imaging,rcbf, regional cerebral blood flow,pharmacological,bold, blood-oxygen level dependent,attention,memory,cholinergic,pet, positron emission tomography,sensory,eeg, electroencephalography,cs, conditioned stimuli,pet,meg, magnetoencephalography,fmri,ltp, long-term potentiation,functional imaging,ach, acetylcholine

                Comments

                Comment on this article