51
|
Fiori F, Chiappini E, Candidi M, Romei V, Borgomaneri S, Avenanti A. Long-latency interhemispheric interactions between motor-related areas and the primary motor cortex: a dual site TMS study. Sci Rep 2017; 7:14936. [PMID: 29097700 PMCID: PMC5668244 DOI: 10.1038/s41598-017-13708-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 09/27/2017] [Indexed: 12/19/2022] Open
Abstract
The primary motor cortex (M1) is highly influenced by premotor/motor areas both within and across hemispheres. Dual site transcranial magnetic stimulation (dsTMS) has revealed interhemispheric interactions mainly at early latencies. Here, we used dsTMS to systematically investigate long-latency causal interactions between right-hemisphere motor areas and the left M1 (lM1). We stimulated lM1 using a suprathreshold test stimulus (TS) to elicit motor-evoked potentials (MEPs) in the right hand. Either a suprathreshold or a subthreshold conditioning stimulus (CS) was applied over the right M1 (rM1), the right ventral premotor cortex (rPMv), the right dorsal premotor cortex (rPMd) or the supplementary motor area (SMA) prior to the TS at various CS-TS inter-stimulus intervals (ISIs: 40–150 ms). The CS strongly affected lM1 excitability depending on ISI, CS site and intensity. Inhibitory effects were observed independently of CS intensity when conditioning PMv, rM1 and SMA at a 40-ms ISI, with larger effects after PMv conditioning. Inhibition was observed with suprathreshold PMv and rM1 conditioning at a 150-ms ISI, while site-specific, intensity-dependent facilitation was detected at an 80-ms ISI. Thus, long-latency interhemispheric interactions, likely reflecting indirect cortico-cortical/cortico-subcortical pathways, cannot be reduced to nonspecific activation across motor structures. Instead, they reflect intensity-dependent, connection- and time-specific mechanisms.
Collapse
Affiliation(s)
- Francesca Fiori
- IRCCS Fondazione Santa Lucia, 00179, Rome, Italy.,Centro studi e ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia, Università di Bologna, 47521, Cesena, Italy.,Dipartimento di Psicologia, Sapienza Università di Roma, 00185, Roma, Italy
| | - Emilio Chiappini
- IRCCS Fondazione Santa Lucia, 00179, Rome, Italy.,Centro studi e ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia, Università di Bologna, 47521, Cesena, Italy
| | - Matteo Candidi
- IRCCS Fondazione Santa Lucia, 00179, Rome, Italy.,Dipartimento di Psicologia, Sapienza Università di Roma, 00185, Roma, Italy
| | - Vincenzo Romei
- Centro studi e ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia, Università di Bologna, 47521, Cesena, Italy.,Centre for Brain Science, Department of Psychology, University of Essex, CO4 3SQ, Colchester, UK
| | - Sara Borgomaneri
- IRCCS Fondazione Santa Lucia, 00179, Rome, Italy.,Centro studi e ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia, Università di Bologna, 47521, Cesena, Italy
| | - Alessio Avenanti
- IRCCS Fondazione Santa Lucia, 00179, Rome, Italy. .,Centro studi e ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia, Università di Bologna, 47521, Cesena, Italy.
| |
Collapse
|
52
|
Hadid V, Lepore F. From Cortical Blindness to Conscious Visual Perception: Theories on Neuronal Networks and Visual Training Strategies. Front Syst Neurosci 2017; 11:64. [PMID: 28912694 PMCID: PMC5583595 DOI: 10.3389/fnsys.2017.00064] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 08/11/2017] [Indexed: 12/13/2022] Open
Abstract
Homonymous hemianopia (HH) is the most common cortical visual impairment leading to blindness in the contralateral hemifield. It is associated with many inconveniences and daily restrictions such as exploration and visual orientation difficulties. However, patients with HH can preserve the remarkable ability to unconsciously perceive visual stimuli presented in their blindfield, a phenomenon known as blindsight. Unfortunately, the nature of this captivating residual ability is still misunderstood and the rehabilitation strategies in terms of visual training have been insufficiently exploited. This article discusses type I and type II blindsight in a neuronal framework of altered global workspace, resulting from inefficient perception, attention and conscious networks. To enhance synchronization and create global availability for residual abilities to reach visual consciousness, rehabilitation tools need to stimulate subcortical extrastriate pathways through V5/MT. Multisensory bottom-up compensation combined with top-down restitution training could target pre-existing and new neuronal mechanisms to recreate a framework for potential functionality.
Collapse
Affiliation(s)
- Vanessa Hadid
- Département de Sciences Biomédicales, Université de MontréalMontréal, QC, Canada
| | - Franco Lepore
- Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Département de Psychologie, Université de MontréalMontréal, QC, Canada
| |
Collapse
|
53
|
Plasticity Beyond V1: Reinforcement of Motion Perception upon Binocular Central Retinal Lesions in Adulthood. J Neurosci 2017; 37:8989-8999. [PMID: 28821647 DOI: 10.1523/jneurosci.1231-17.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/03/2017] [Accepted: 08/08/2017] [Indexed: 11/21/2022] Open
Abstract
Induction of a central retinal lesion in both eyes of adult mammals is a model for macular degeneration and leads to retinotopic map reorganization in the primary visual cortex (V1). Here we characterized the spatiotemporal dynamics of molecular activity levels in the central and peripheral representation of five higher-order visual areas, V2/18, V3/19, V4/21a,V5/PMLS, area 7, and V1/17, in adult cats with central 10° retinal lesions (both sexes), by means of real-time PCR for the neuronal activity reporter gene zif268. The lesions elicited a similar, permanent reduction in activity in the center of the lesion projection zone of area V1/17, V2/18, V3/19, and V4/21a, but not in the motion-driven V5/PMLS, which instead displayed an increase in molecular activity at 3 months postlesion, independent of visual field coordinates. Also area 7 only displayed decreased activity in its LPZ in the first weeks postlesion and increased activities in its periphery from 1 month onward. Therefore we examined the impact of central vision loss on motion perception using random dot kinematograms to test the capacity for form from motion detection based on direction and velocity cues. We revealed that the central retinal lesions either do not impair motion detection or even result in better performance, specifically when motion discrimination was based on velocity discrimination. In conclusion, we propose that central retinal damage leads to enhanced peripheral vision by sensitizing the visual system for motion processing relying on feedback from V5/PMLS and area 7.SIGNIFICANCE STATEMENT Central retinal lesions, a model for macular degeneration, result in functional reorganization of the primary visual cortex. Examining the level of cortical reactivation with the molecular activity marker zif268 revealed reorganization in visual areas outside V1. Retinotopic lesion projection zones typically display an initial depression in zif268 expression, followed by partial recovery with postlesion time. Only the motion-sensitive area V5/PMLS shows no decrease, and even a significant activity increase at 3 months post-retinal lesion. Behavioral tests of motion perception found no impairment and even better sensitivity to higher random dot stimulus velocities. We demonstrate that the loss of central vision induces functional mobilization of motion-sensitive visual cortex, resulting in enhanced perception of moving stimuli.
Collapse
|
54
|
Fiori F, Chiappini E, Soriano M, Paracampo R, Romei V, Borgomaneri S, Avenanti A. Long-latency modulation of motor cortex excitability by ipsilateral posterior inferior frontal gyrus and pre-supplementary motor area. Sci Rep 2016; 6:38396. [PMID: 27929075 PMCID: PMC5144072 DOI: 10.1038/srep38396] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/08/2016] [Indexed: 02/08/2023] Open
Abstract
The primary motor cortex (M1) is strongly influenced by several frontal regions. Dual-site transcranial magnetic stimulation (dsTMS) has highlighted the timing of early (<40 ms) prefrontal/premotor influences over M1. Here we used dsTMS to investigate, for the first time, longer-latency causal interactions of the posterior inferior frontal gyrus (pIFG) and pre-supplementary motor area (pre-SMA) with M1 at rest. A suprathreshold test stimulus (TS) was applied over M1 producing a motor-evoked potential (MEP) in the relaxed hand. Either a subthreshold or a suprathreshold conditioning stimulus (CS) was administered over ipsilateral pIFG/pre-SMA sites before the TS at different CS-TS inter-stimulus intervals (ISIs: 40-150 ms). Independently of intensity, CS over pIFG and pre-SMA (but not over a control site) inhibited MEPs at an ISI of 40 ms. The CS over pIFG produced a second peak of inhibition at an ISI of 150 ms. Additionally, facilitatory modulations were found at an ISI of 60 ms, with supra- but not subthreshold CS intensities. These findings suggest differential modulatory roles of pIFG and pre-SMA in M1 excitability. In particular, the pIFG -but not the pre-SMA- exerts intensity-dependent modulatory influences over M1 within the explored time window of 40-150 ms, evidencing fine-tuned control of M1 output.
Collapse
Affiliation(s)
- Francesca Fiori
- Dipartimento di Psicologia and Centro studi e ricerche in Neuroscienze Cognitive, Campus di Cesena, Università di Bologna 47521 Cesena, Italy.,IRCCS Fondazione Santa Lucia, 00179 Rome, Italy.,Dipartimento di Psicologia, Sapienza Università di Roma, 00185 Rome, Italy
| | - Emilio Chiappini
- Dipartimento di Psicologia and Centro studi e ricerche in Neuroscienze Cognitive, Campus di Cesena, Università di Bologna 47521 Cesena, Italy
| | - Marco Soriano
- Dipartimento di Psicologia and Centro studi e ricerche in Neuroscienze Cognitive, Campus di Cesena, Università di Bologna 47521 Cesena, Italy
| | - Riccardo Paracampo
- Dipartimento di Psicologia and Centro studi e ricerche in Neuroscienze Cognitive, Campus di Cesena, Università di Bologna 47521 Cesena, Italy
| | - Vincenzo Romei
- Centre for Brain Science, Department of Psychology, University of Essex, UK
| | - Sara Borgomaneri
- Dipartimento di Psicologia and Centro studi e ricerche in Neuroscienze Cognitive, Campus di Cesena, Università di Bologna 47521 Cesena, Italy.,IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
| | - Alessio Avenanti
- Dipartimento di Psicologia and Centro studi e ricerche in Neuroscienze Cognitive, Campus di Cesena, Università di Bologna 47521 Cesena, Italy.,IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
| |
Collapse
|
56
|
Romei V, Thut G, Silvanto J. Information-Based Approaches of Noninvasive Transcranial Brain Stimulation. Trends Neurosci 2016; 39:782-795. [PMID: 27697295 DOI: 10.1016/j.tins.2016.09.001] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 09/01/2016] [Accepted: 09/06/2016] [Indexed: 11/16/2022]
Abstract
Progress in cognitive neuroscience relies on methodological developments to increase the specificity of knowledge obtained regarding brain function. For example, in functional neuroimaging the current trend is to study the type of information carried by brain regions rather than simply compare activation levels induced by task manipulations. In this context noninvasive transcranial brain stimulation (NTBS) in the study of cognitive functions may appear coarse and old fashioned in its conventional uses. However, in their multitude of parameters, and by coupling them with behavioral manipulations, NTBS protocols can reach the specificity of imaging techniques. Here we review the different paradigms that have aimed to accomplish this in both basic science and clinical settings and follow the general philosophy of information-based approaches.
Collapse
Affiliation(s)
- Vincenzo Romei
- Centre for Brain Science, Department of Psychology, University of Essex, Colchester, UK.
| | - Gregor Thut
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK.
| | - Juha Silvanto
- Department of Psychology, Faculty of Science and Technology, University of Westminster, London, UK.
| |
Collapse
|