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Cortico-cortical communication dynamics.

Roland PE, Hilgetag CC, Deco G - Front Syst Neurosci (2014)

Bottom Line: For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived.As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG), and a combination of invasive measurements in animal experiments.Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen Copenhagen, Denmark.

ABSTRACT
In principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG), and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

No MeSH data available.


Related in: MedlinePlus

Temporal dynamics of multiunit activity and local field potentials, and spatio-temporal dynamics of the voltage sensitive dye signal in the barrel field of the mouse during up-state and down-state. Top: (A) Spontaneous multi-unit activity and local field potential at the D 2 barrel during three consecutive up-states. (B) Multi-unit activity after stimulating the whisker at 0 ms during an up-state, in the first half of a down-state, and in the last part of the down state. Note the different time scales. (C) The spatio-temporal spread of the increase in population membrane potential (voltage sensitive dye signal), after whisker stimulation during an up-state, in the first half of a down-state, and in the last part of the down state (from Civillico and Contreras, 2012). Notably the whisker stimulus only modifies the oscillation in one cycle, but does not alter the future oscillations.
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Figure 2: Temporal dynamics of multiunit activity and local field potentials, and spatio-temporal dynamics of the voltage sensitive dye signal in the barrel field of the mouse during up-state and down-state. Top: (A) Spontaneous multi-unit activity and local field potential at the D 2 barrel during three consecutive up-states. (B) Multi-unit activity after stimulating the whisker at 0 ms during an up-state, in the first half of a down-state, and in the last part of the down state. Note the different time scales. (C) The spatio-temporal spread of the increase in population membrane potential (voltage sensitive dye signal), after whisker stimulation during an up-state, in the first half of a down-state, and in the last part of the down state (from Civillico and Contreras, 2012). Notably the whisker stimulus only modifies the oscillation in one cycle, but does not alter the future oscillations.

Mentions: In later years scientists have become increasingly aware that the spontaneous and intrinsic ongoing fluctuations in the membrane potentials and firing of action potentials have a profound effect on sensory evoked activity when it arrives to primary sensory areas (Destexhe, 2011). For example, it has been debated whether sensory evoked r(t) and dVm(t)/dt increases are favored by up-states or down states (Steriade et al., 1993; Contreras et al., 1996; Paré et al., 1998; Destexhe et al., 1999; Petersen et al., 2003b; Crochet and Petersen, 2006; Haider et al., 2006; Luczak et al., 2007). Up-states are associated with high inhibitory and excitatory conductances; whereas in down-states the conductances are smaller, but often coupled to a leak conductance (Contreras et al., 1996; Haider et al., 2006). Civillico and Contreras (2012) induced oscillation between a down-state and an up-state with ketamine-xylazine. They then examined how the phases of the up-state and down-state affected the arrivals of r(t)s from thalamus and the membrane potentials in the barrel cortex. They found that the local field potentials, the membrane potential changes and the multi-unit activity in the barrel cortex increased less to a whisker stimulus applied during the up-state, as compared to whisker stimulus applied in the later part of the down-state (Figure 2). When the whisker stimulus was given when the membrane was maximally hyperpolarized or when the hyperpolarization diminished in the oscillatory cycle, the whisker stimulus almost invariably triggered an up-state during which the amplitude of the local field potential, the membrane potential and the multi-unit activity was strong (Figure 2). Also the spreading of the depolarization to the whole barrel field was much stronger.


Cortico-cortical communication dynamics.

Roland PE, Hilgetag CC, Deco G - Front Syst Neurosci (2014)

Temporal dynamics of multiunit activity and local field potentials, and spatio-temporal dynamics of the voltage sensitive dye signal in the barrel field of the mouse during up-state and down-state. Top: (A) Spontaneous multi-unit activity and local field potential at the D 2 barrel during three consecutive up-states. (B) Multi-unit activity after stimulating the whisker at 0 ms during an up-state, in the first half of a down-state, and in the last part of the down state. Note the different time scales. (C) The spatio-temporal spread of the increase in population membrane potential (voltage sensitive dye signal), after whisker stimulation during an up-state, in the first half of a down-state, and in the last part of the down state (from Civillico and Contreras, 2012). Notably the whisker stimulus only modifies the oscillation in one cycle, but does not alter the future oscillations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4017159&req=5

Figure 2: Temporal dynamics of multiunit activity and local field potentials, and spatio-temporal dynamics of the voltage sensitive dye signal in the barrel field of the mouse during up-state and down-state. Top: (A) Spontaneous multi-unit activity and local field potential at the D 2 barrel during three consecutive up-states. (B) Multi-unit activity after stimulating the whisker at 0 ms during an up-state, in the first half of a down-state, and in the last part of the down state. Note the different time scales. (C) The spatio-temporal spread of the increase in population membrane potential (voltage sensitive dye signal), after whisker stimulation during an up-state, in the first half of a down-state, and in the last part of the down state (from Civillico and Contreras, 2012). Notably the whisker stimulus only modifies the oscillation in one cycle, but does not alter the future oscillations.
Mentions: In later years scientists have become increasingly aware that the spontaneous and intrinsic ongoing fluctuations in the membrane potentials and firing of action potentials have a profound effect on sensory evoked activity when it arrives to primary sensory areas (Destexhe, 2011). For example, it has been debated whether sensory evoked r(t) and dVm(t)/dt increases are favored by up-states or down states (Steriade et al., 1993; Contreras et al., 1996; Paré et al., 1998; Destexhe et al., 1999; Petersen et al., 2003b; Crochet and Petersen, 2006; Haider et al., 2006; Luczak et al., 2007). Up-states are associated with high inhibitory and excitatory conductances; whereas in down-states the conductances are smaller, but often coupled to a leak conductance (Contreras et al., 1996; Haider et al., 2006). Civillico and Contreras (2012) induced oscillation between a down-state and an up-state with ketamine-xylazine. They then examined how the phases of the up-state and down-state affected the arrivals of r(t)s from thalamus and the membrane potentials in the barrel cortex. They found that the local field potentials, the membrane potential changes and the multi-unit activity in the barrel cortex increased less to a whisker stimulus applied during the up-state, as compared to whisker stimulus applied in the later part of the down-state (Figure 2). When the whisker stimulus was given when the membrane was maximally hyperpolarized or when the hyperpolarization diminished in the oscillatory cycle, the whisker stimulus almost invariably triggered an up-state during which the amplitude of the local field potential, the membrane potential and the multi-unit activity was strong (Figure 2). Also the spreading of the depolarization to the whole barrel field was much stronger.

Bottom Line: For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived.As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG), and a combination of invasive measurements in animal experiments.Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen Copenhagen, Denmark.

ABSTRACT
In principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG), and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

No MeSH data available.


Related in: MedlinePlus