Influence of anesthesia on spontaneous activity and receptive field size of single units in rat Sm1 neocortex

Armstrong‐James, Michael; George, M. J.

doi:10.1016/0014-4886(88)90155-0

Cited by 83 publications

(25 citation statements)

References 34 publications

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“…A majority of neurons in L4 and L5a exhibit a prompt response to self-induced contact (Crochet and Petersen, 2006; Curtis and Kleinfeld, 2009; O'Connor et al, 2010b), not unlike that observed in experiments with mechanical stimulation of a vibrissa in an anesthetized preparation (Armstrong-James et al, 1992; Armstrong-James and George, 1988; Simons, 1978). The strength of the contact response as a function of the phase in the whisk cycle was found for eight different phase intervals of π/4 radians.…”

Section: Cortical Representation Of Touchmentioning

confidence: 84%

Neuronal Basis for Object Location in the Vibrissa Scanning Sensorimotor System

Kleinfeld

Deschênes

2011

Neuron

140

144

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An essential issue in perception is how the location of an object is estimated from tactile signals in the context of self-generated changes in sensor configuration. Here, we review the pathways and dynamics of neuronal signals that encode touch in the rodent vibrissa sensorimotor system. Rodents rhythmically scan an array of long, facial hairs across a region of interest. Behavioral evidence shows that these animals maintain knowledge of the azimuthal position of their vibrissae. Electrophysiological measurements have identified a reafferent signal of the azimuth that is coded in normalized coordinates, broadcast throughout primary sensory cortex and provides strong modulation of signals of vibrissa contact. Efferent signals in motor cortex report the range of the scan. Collectively, these signals allow the rodent to form a percept of object location.

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Section: Cortical Representation Of Touchmentioning

confidence: 84%

Neuronal Basis for Object Location in the Vibrissa Scanning Sensorimotor System

Kleinfeld

Deschênes

2011

Neuron

140

144

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“…Anesthetics are known to suppress spontaneous ongoing neuronal activity in a dose-dependent manner (Robson, 1967; Ikeda and Wright, 1974; Armstrong-James and George, 1988; Angel, 1991; Ogawa et al, 1992; Villeneuve and Casanova, 2003; Hentschke et al, 2005; Sellers et al, 2013). However, the critical neuronal events that account for the suppression of consciousness remain unknown (Alkire et al, 2008; Mashour, 2014; Meyer, 2015).…”

Section: Discussionmentioning

confidence: 99%

Repertoire of mesoscopic cortical activity is not reduced during anesthesia

et al. 2016

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Consciousness has been linked to the repertoire of brain states at various spatiotemporal scales. Anesthesia is thought to modify consciousness by altering information integration in cortical and thalamocortical circuits. At a mesoscopic scale, neuronal populations in the cortex form synchronized ensembles whose characteristics are presumably state-dependent but this has not been rigorously tested. In this study, spontaneous neuronal activity was recorded with 64-contact microelectrode arrays in primary visual cortex of chronically instrumented, unrestrained rats under stepwise decreasing levels of desflurane anesthesia (8%, 6%, 4%, and 2% inhaled concentrations) and wakefulness (0% concentration). Negative phases of the local field potentials formed compact, spatially contiguous activity patterns (CAPs) that were not due to chance. The number of CAPs was 120% higher in wakefulness and deep anesthesia associated with burst-suppression than at intermediate levels of consciousness. The frequency distribution of CAP sizes followed a power–law with slope −1.5 in relatively deep anesthesia (8–6%) but deviated from that at the lighter levels. Temporal variance and entropy of CAP sizes were lowest in wakefulness (76% and 24% lower at 0% than at 8% desflurane, respectively) but changed little during recovery of consciousness. CAPs categorized by K-means clustering were conserved at all anesthesia levels and wakefulness, although their proportion changed in a state-dependent manner. These observations yield new knowledge about the dynamic landscape of ongoing population activity in sensory cortex at graded levels of anesthesia. The repertoire of population activity and self-organized criticality at the mesoscopic scale do not appear to contribute to anesthetic suppression of consciousness, which may instead depend on large-scale effects, more subtle dynamic properties, or changes outside of primary sensory cortex.

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“…It has been known that older general anesthetics reduce baseline neuron firing in visual 1 and other sensory systems 41,42. Ogawa et al 43,44 found that volatile anesthetics halothane, isoflurane, enflurane and sevoflurane suppressed multiunit activity in the reticular formation, but they did not study cortical units and only investigated the effect of anesthetic concentrations higher than those that produce loss of consciousness.…”

Section: Discussionmentioning

confidence: 99%

Desflurane Selectively Suppresses Long-latency Cortical Neuronal Response to Flash in the Rat

Hudetz¹,

Vizuete

Imas

2009

Anesthesiology

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Background The effect of inhalational anesthetics on sensory-evoked unit activity in the cerebral cortex has been controversial. Desflurane has desirable properties for in vivo neurophysiologic studies but its effect on cortical neuronal activity and neuronal responsiveness is not known. We studied the effect of desflurane on resting and visual evoked unit activity in rat visual cortex in vivo. Methods Desflurane was administered to adult albino rats at steady-state concentrations at 2%, 4%, 6% and 8%. Flashes from a light emitting diode were delivered to the left eye at 5-second intervals. Extracellular unit activity within the right visual cortex was recorded using a 49-electrode array. Individual units were identified using principal components analysis. Results At 2% desflurane 578 active units were found. Of these, 75% increased their firing rate in response to flash. Most responses contained early (0–100ms) and late (150–1000ms) components. With increasing desflurane concentration, the number of units active at baseline decreased (−13%), the number of early responding units increased (+31%), and number of late responding units decreased (−15%). Simultaneously, baseline firing rate decreased (−77%), the early response was unchanged, and the late response decreased (−60%). Conclusions The results indicate that visual cortex neurons remain responsive to flash stimulation under desflurane anesthesia but the long-latency component of their response is attenuated in a concentration-dependent manner. Suppression of the long-latency response may be related to a loss of cortico-cortical feedback and loss of consciousness.

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Influence of anesthesia on spontaneous activity and receptive field size of single units in rat Sm1 neocortex

Cited by 83 publications

References 34 publications

Neuronal Basis for Object Location in the Vibrissa Scanning Sensorimotor System

Neuronal Basis for Object Location in the Vibrissa Scanning Sensorimotor System

Repertoire of mesoscopic cortical activity is not reduced during anesthesia

Desflurane Selectively Suppresses Long-latency Cortical Neuronal Response to Flash in the Rat

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