1
|
Neural Dynamics in Primate Cortex during Exposure to Subanesthetic Concentrations of Nitrous Oxide. eNeuro 2021; 8:ENEURO.0479-20.2021. [PMID: 34135005 PMCID: PMC8281265 DOI: 10.1523/eneuro.0479-20.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 05/07/2021] [Accepted: 05/31/2021] [Indexed: 11/21/2022] Open
Abstract
Nitrous oxide (N2O) is a hypnotic gas with antidepressant and psychedelic properties at subanesthetic concentrations. Despite long-standing clinical use, there is insufficient understanding of its effect on neural dynamics and cortical processing, which is important for mechanistic understanding of its therapeutic effects. We administered subanesthetic (70%), inhaled N2O and studied the dynamic changes of spiking rate, spectral content, and somatosensory information representation in primary motor cortex (M1) in two male rhesus macaques implanted with Utah microelectrode arrays in the hand area of M1. The average sorted multiunit spiking rate in M1 increased from 8.1 ± 0.99 to 10.6 ± 1.3 Hz in Monkey W (p < 0.001) and from 5.6 ± 0.87 to 7.0 ± 1.1 Hz in Monkey N (p = 0.003). Power spectral densities increased in beta- and gamma-band power. To evaluate somatosensory content in M1 as a surrogate of information transfer, fingers were lightly brushed and classified using a naive Bayes classifier. In both monkeys, the proportion of correctly classified fingers dropped from 0.50 ± 0.06 before N2O inhalation to 0.34 ± 0.03 during N2O inhalation (p = 0.018), although some fingers continued to be correctly classified (p = 0.005). The decrease in correct classifications corresponded to decreased modulation depth for the population (p = 0.005) and fewer modulated units (p = 0.046). However, the increased single-unit firing rate was not correlated with its modulation depth (R2 < 0.001, p = 0.93). These data suggest that N2O degrades information transfer, although no clear relationship was found between neuronal tuning and N2O-induced changes in firing rate.
Collapse
|
2
|
Yamawaki N, Raineri Tapies MG, Stults A, Smith GA, Shepherd GMG. Circuit organization of the excitatory sensorimotor loop through hand/forelimb S1 and M1. eLife 2021; 10:e66836. [PMID: 33851917 PMCID: PMC8046433 DOI: 10.7554/elife.66836] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/03/2021] [Indexed: 12/16/2022] Open
Abstract
Sensory-guided limb control relies on communication across sensorimotor loops. For active touch with the hand, the longest loop is the transcortical continuation of ascending pathways, particularly the lemnisco-cortical and corticocortical pathways carrying tactile signals via the cuneate nucleus, ventral posterior lateral (VPL) thalamus, and primary somatosensory (S1) and motor (M1) cortices to reach corticospinal neurons and influence descending activity. We characterized excitatory connectivity along this pathway in the mouse. In the lemnisco-cortical leg, disynaptic cuneate→VPL→S1 connections excited mainly layer (L) 4 neurons. In the corticocortical leg, S1→M1 connections from L2/3 and L5A neurons mainly excited downstream L2/3 neurons, which excite corticospinal neurons. The findings provide a detailed new wiring diagram for the hand/forelimb-related transcortical circuit, delineating a basic but complex set of cell-type-specific feedforward excitatory connections that selectively and extensively engage diverse intratelencephalic projection neurons, thereby polysynaptically linking subcortical somatosensory input to cortical motor output to spinal cord.
Collapse
Affiliation(s)
- Naoki Yamawaki
- Department of Physiology, Feinberg School of Medicine, Northwestern UniversityChicagoUnited States
| | | | - Austin Stults
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern UniversityChicagoUnited States
| | - Gregory A Smith
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern UniversityChicagoUnited States
| | - Gordon MG Shepherd
- Department of Physiology, Feinberg School of Medicine, Northwestern UniversityChicagoUnited States
| |
Collapse
|
3
|
Tamè L, Tucciarelli R, Sadibolova R, Sereno MI, Longo MR. Reconstructing neural representations of tactile space. Neuroimage 2021; 229:117730. [PMID: 33454399 DOI: 10.1016/j.neuroimage.2021.117730] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/18/2020] [Accepted: 01/07/2021] [Indexed: 01/29/2023] Open
Abstract
Psychophysical experiments have demonstrated large and highly systematic perceptual distortions of tactile space. Such a space can be referred to our experience of the spatial organisation of objects, at representational level, through touch, in analogy with the familiar concept of visual space. We investigated the neural basis of tactile space by analysing activity patterns induced by tactile stimulation of nine points on a 3 × 3 square grid on the hand dorsum using functional magnetic resonance imaging. We used a searchlight approach within pre-defined regions of interests to compute the pairwise Euclidean distances between the activity patterns elicited by tactile stimulation. Then, we used multidimensional scaling to reconstruct tactile space at the neural level and compare it with skin space at the perceptual level. Our reconstructions of the shape of skin space in contralateral primary somatosensory and motor cortices reveal that it is distorted in a way that matches the perceptual shape of skin space. This suggests that early sensorimotor areas critically contribute to the distorted internal representation of tactile space on the hand dorsum.
Collapse
Affiliation(s)
- Luigi Tamè
- Department of Psychological Sciences, Birkbeck, University of London, London WC1E 7HX, UK; School of Psychology, University of Kent, Canterbury CT2 7NP, UK.
| | - Raffaele Tucciarelli
- Department of Psychological Sciences, Birkbeck, University of London, London WC1E 7HX, UK
| | - Renata Sadibolova
- Department of Psychological Sciences, Birkbeck, University of London, London WC1E 7HX, UK; Department of Psychology, Goldsmith, University of London, London, UK
| | - Martin I Sereno
- Department of Psychological Sciences, Birkbeck, University of London, London WC1E 7HX, UK; University College London, University of London, London, UK; San Diego State University, San Diego, USA
| | - Matthew R Longo
- Department of Psychological Sciences, Birkbeck, University of London, London WC1E 7HX, UK.
| |
Collapse
|
4
|
Tamè L, Pavani F, Braun C, Salemme R, Farnè A, Reilly KT. Somatotopy and temporal dynamics of sensorimotor interactions: evidence from double afferent inhibition. Eur J Neurosci 2015; 41:1459-65. [DOI: 10.1111/ejn.12890] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 03/06/2015] [Accepted: 03/06/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Luigi Tamè
- Department of Psychological Sciences; Birkbeck; University of London; Malet Street London; WC1E 7HX London UK
- INSERM U1028; CNRS UMR5292; ImpAct Team; Lyon Neuroscience Research Centre; Lyon France
- Center for Mind/Brain Sciences; University of Trento; Rovereto Italy
| | - Francesco Pavani
- Center for Mind/Brain Sciences; University of Trento; Rovereto Italy
- Department of Psychology and Cognitive Sciences; University of Trento; Rovereto Italy
| | - Christoph Braun
- Center for Mind/Brain Sciences; University of Trento; Rovereto Italy
- Department of Psychology and Cognitive Sciences; University of Trento; Rovereto Italy
- MEG-Zentrum; University Tübingen; Tübingen Germany
| | - Romeo Salemme
- INSERM U1028; CNRS UMR5292; ImpAct Team; Lyon Neuroscience Research Centre; Lyon France
- University Claude Bernard Lyon I; Lyon France
| | - Alessandro Farnè
- INSERM U1028; CNRS UMR5292; ImpAct Team; Lyon Neuroscience Research Centre; Lyon France
- University Claude Bernard Lyon I; Lyon France
| | - Karen T. Reilly
- INSERM U1028; CNRS UMR5292; ImpAct Team; Lyon Neuroscience Research Centre; Lyon France
- University Claude Bernard Lyon I; Lyon France
| |
Collapse
|
5
|
Hoy KE, Fitzgerald PB, Bradshaw JL, Armatas CA, Georgiou-Karistianis N. Investigating the cortical origins of motor overflow. ACTA ACUST UNITED AC 2004; 46:315-27. [PMID: 15571773 DOI: 10.1016/j.brainresrev.2004.07.013] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2004] [Indexed: 11/22/2022]
Abstract
Motor overflow refers to the involuntary movements which may accompany the production of voluntary movements. While overflow is not usually seen in the normal population, it does present in children and the elderly, as well as those suffering certain neurological dysfunctions. Advancements in methodology over the last decade have allowed for more convincing conclusions regarding the cortical origins of motor overflow. However, despite significant research, the exact mechanism underlying the production of motor overflow is still unclear. This review presents a more comprehensive conceptualization of the theories of motor overflow, which have often been only vaguely defined. Further, the major findings are explored in an attempt to differentiate the competing theories of motor overflow production. This exploration is done in the context of a range of neurological and psychiatric disorders, in order to elucidate the possible underlying mechanisms of overflow.
Collapse
Affiliation(s)
- Kate E Hoy
- Experimental Neuropsychology Research Unit, Psychology Department, Monash University, Clayton 3800, Victoria, Australia.
| | | | | | | | | |
Collapse
|
6
|
Kleinfeld D, Sachdev RNS, Merchant LM, Jarvis MR, Ebner FF. Adaptive filtering of vibrissa input in motor cortex of rat. Neuron 2002; 34:1021-34. [PMID: 12086648 DOI: 10.1016/s0896-6273(02)00732-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We studied the transformation of sensory input as it progresses from vibrissa primary sensor (S1) to motor (M1) cortex. Single-unit activity was obtained from alert adult rats that did not to whisk upon application of punctate, rhythmic stimulation of individual vibrissae. The spike response of units in S1 cortex largely reproduced the shape of the stimulus. In contrast, the spiking output of units in M1 cortex were modulated solely as a sinusoid at the repetition rate of the stimulus for frequencies between 5 and 15 Hz; this range corresponds to that of natural whisking. Thus, the S1 to M1 transformation extracts the fundamental frequency from a spectrally rich stimulus. We discuss our results in terms of a band-pass filter with a center frequency that adapts to the change in stimulation rate.
Collapse
Affiliation(s)
- David Kleinfeld
- Department of Physics, Graduate program in Neurosciences, University of Californai, San Diego, La Jolla, CA 92093, USA.
| | | | | | | | | |
Collapse
|
7
|
Alstermark B, Ohlson S. Origin of corticospinal neurones evoking monosynaptic excitation in C3--C4 propriospinal neurones in the cat. Neurosci Res 2000; 38:249-56. [PMID: 11070191 DOI: 10.1016/s0168-0102(00)00160-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intracellular recording was made from propriospinal neurones (PNs) in the C3-C4 spinal cord segments in the cat (alpha-chloralose anaesthesia). The effect of electrical stimulation of corticospinal neurones (CSNs) in the cortex was investigated. Short C3-C4 PNs were identified by antidromic activation of their axons in the ventral horn in C6/C7 and in the lateral reticular nucleus. Long PNs were antidromically identified from Th12-13. In short PNs, monosynaptic excitory postsynoptic potentials (EPSPs) were elicited from the rostral part of the lateral sigmoid gyrus, the lateral part of the anterior sigmoid gyrus in area 4 gamma and in the adjacent area 6. Two subtypes of short PNs were identified. PNs of type I received monosynaptic EPSPs from the rostral part of the lateral sigmoid gyrus, the lateral part of the anterior sigmoid gyrus in area 4 gamma, which is from the same region as disynaptic cortical EPSPs were evoked in forelimb motoneurones. PNs of type II received monosynaptic EPSPs from regions slightly more rostrally in the anterior sigmoid gyrus in area 4 gamma and in the adjacent area 6, which is outside the region from which disynaptic EPSPs could be evoked in forelimb motoneurones. Long PNs received monosynaptic EPSPs, like the short PNs, by stimulation in the rostral part of the lateral sigmoid gyrus, the lateral part of the anterior sigmoid gyrus in area 4 gamma and in the adjacent area 6. In contrast, the long PNs also received monosynaptic EPSPs from area 3b near the border of area 1. The present results show segregation of the cortical control to functionally different premotoneuronal systems and suggest that this control could in part be separated for subtypes of short C3-C4 PNs.
Collapse
Affiliation(s)
- B Alstermark
- Department of Integrative Medical Biology, Section of Physiology, Umeå University, S-901 87 Umeå, Sweden.
| | | |
Collapse
|
8
|
Farkas T, Kis Z, Toldi J, Wolff JR. Activation of the primary motor cortex by somatosensory stimulation in adult rats is mediated mainly by associational connections from the somatosensory cortex. Neuroscience 1999; 90:353-61. [PMID: 10215140 DOI: 10.1016/s0306-4522(98)00451-5] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In anaesthetized adult rats, facial nerve injury causes a disinhibition of the interhemispheric connections between homotopic representation fields in the primary motor cortex with a latency of 4 min (Toldi et al., 1996, Neurosci Lett. 203, 179-182). One possible explanation for the induction of such rapid changes is an alteration of the somatosensory input to the motor cortex. To test this hypothesis, unit activity in primary motor cortex was recorded during electrical stimulation of trigeminal afferents in the contralateral whisker-pad. About one-third of all recorded primary motor cortex neurons responded with latencies shorter than in the ventrolateral and posterior nuclei of the thalamus. Responses failed at stimulation frequencies > or = 10 Hz and after elimination or inactivation of the somatosensory cortex. Within primary motor cortex, the activatable neurons displayed a bilaminar distribution and were identified as pyramidal neurons by neurobiotin labelling. The results suggest that trigeminal afferents participate in modulation of the activity of primary motor cortex output neurons via primary somatosensory cortex-to-primary motor cortex associational connections, even under anaesthesia.
Collapse
Affiliation(s)
- T Farkas
- Department of Anatomy, Georg-August-University, Göttingen, Germany
| | | | | | | |
Collapse
|
9
|
Jörntell H, Ekerot CF. Topographical organization of projections to cat motor cortex from nucleus interpositus anterior and forelimb skin. J Physiol 1999; 514 ( Pt 2):551-66. [PMID: 9852335 PMCID: PMC2269074 DOI: 10.1111/j.1469-7793.1999.551ae.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
1. The activation of the motor cortex from focal electrical stimulation of sites in the forelimb area of cerebellar nucleus interpositus anterior (NIA) was investigated in barbiturate-anaesthetized cats. Using a microelectrode, nuclear sites were identified by the cutaneous climbing fibre receptive fields of their afferent Purkinje cells. These cutaneous receptive fields can be identified by positive field potentials reflecting inhibition from Purkinje cells activated on natural stimulation of the skin. Thereafter, the sites were microstimulated and the evoked responses were systematically recorded over the cortical surface with a ball-tipped electrode. The topographical organization in the motor cortex of responses evoked by electrical stimulation of the forelimb skin was also analysed. 2. Generally, sites in the forelimb area of NIA projected to the lateral part of the anterior sigmoid gyrus (ASG). Sites in the hindlimb area of NIA also projected to lateral ASG and in addition to a more medial region. Sites in the face area of NIA, however, projected mainly to the middle part of the posterior sigmoid gyrus (PSG). 3. For sites in the forelimb area of NIA, the topographical organization and strength of the projections varied specifically with the cutaneous climbing fibre receptive field of the site. The largest cortical responses were evoked from sites with receptive fields on the distal or ventral skin of the forelimb. 4. Microelectrode recordings in the depth of the motor cortex revealed that responses evoked by cerebellar nuclear stimulation were due to an excitatory process in layer III. 5. Short latency surface responses evoked from the forelimb skin were found in the caudolateral part of the motor cortex. At gradually longer latencies, responses appeared in sequentially more rostromedial parts of the motor cortex. Since the responses displayed several temporal peaks that appeared in specific cortical regions for different areas of the forelimb skin, several somatotopic maps were seen. 6. The cerebellar and cutaneous projections activated mainly different cortical regions and had topographical organizations that apparently were constant between animals. Their patterns of activation may constitute a frame of reference for investigations of the functional organization of the motor cortex.
Collapse
Affiliation(s)
- H Jörntell
- Department of Physiology and Neuroscience, University of Lund, Solvegatan 19, S-223 62 Lund, Sweden.
| | | |
Collapse
|