Electrophysiology of the Cerebellar Networks

Llinás, Rodolfó R.

doi:10.1002/cphy.cp010217

Cited by 49 publications

(19 citation statements)

References 172 publications

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“…The CSD maps showed a negative current corresponding to the averaged fEPSC with a maximum 5-8 ms after stimulation, reflecting Na ϩ entry via PC AMPA receptors. A delayed maximum positive current was recorded at the same depth 10 -20 ms after stimulation, reflecting an outward gK Ca 2ϩ gated by voltagesensitive P/Q-type Ca 2ϩ channels (Llinas, 1981; Womack et al, 2009). The CSD maps also revealed a second positive current at a depth of 100 m with the same timing as the fEPSC (i.e., 5-8 ms after stimulation), which most likely corresponded to another outward K ϩ current (Frey et al, 2009).…”

Section: Frequency Dependence Of Neuronal Camentioning

confidence: 99%

“…PC spike activity was quantified by calculating the root mean square (rms) of the spike trace, while spike interval histogram (INTH) analysis was applied to illustrate changes in PC spiking rhythm. The poststimulus refractory period is the period from the end of stimulation to the recovery of spiking to prestimulus levels and reflects the activity of the Ca 2ϩ -gated K ϩ current ( gK Ca ) (Llinas, 1981;Womack et al, 2009).…”

Section: Electrophysiological Recordingsmentioning

confidence: 99%

“…The CSD maps obtained in this manner identified the location and amplitude of the negative and positive currents. At a cortical depth of 50 m, the amplitude of the negative current is proportional to the magnitude of the field (i.e., extracellular) EPSC (fEPSC) and reflects Na ϩ influx into PCs via AMPA receptor channels, while the delayed positive current represents K ϩ efflux out of PCs via P/Q-type gK Ca (Llinas, 1981;Womack et al, 2009). The reverse current pattern is observed at a depth of 100 m due to the anatomical and electrophysiological properties of the PCs (Llinas, 1981).…”

Section: Csd Calculationmentioning

confidence: 99%

“…At a cortical depth of 50 m, the amplitude of the negative current is proportional to the magnitude of the field (i.e., extracellular) EPSC (fEPSC) and reflects Na ϩ influx into PCs via AMPA receptor channels, while the delayed positive current represents K ϩ efflux out of PCs via P/Q-type gK Ca (Llinas, 1981;Womack et al, 2009). The reverse current pattern is observed at a depth of 100 m due to the anatomical and electrophysiological properties of the PCs (Llinas, 1981). We calculated the summed fEPSCs (ΑfESPC) as fESPC amplitude ϫ stimulation frequency ϫ duration of stimulation train, which represents the transmembrane Na ϩ flux into PCs during the stimulation period (Mathiesen et al, 1998).…”

Section: Csd Calculationmentioning

confidence: 99%

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Activity-dependent Increases in Local Oxygen Consumption Correlate with Postsynaptic Currents in the Mouse CerebellumIn Vivo

Mathiesen¹,

Caesar²,

Thomsen³

et al. 2011

J. Neurosci.

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Evoked neural activity correlates strongly with rises in cerebral metabolic rate of oxygen (CMRO 2 ) and cerebral blood flow (CBF). Activity-dependent rises in CMRO 2 fluctuate with ATP turnover due to ion pumping. In vitro studies suggest that increases in cytosolic Ca 2ϩ stimulate oxidative metabolism via mitochondrial signaling, but whether this also occurs in the intact brain is unknown. Here we applied a pharmacological approach to dissect the effects of ionic currents and cytosolic Ca 2ϩ rises of neuronal origin on activitydependent rises in CMRO 2 . We used two-photon microscopy and current source density analysis to study real-time Ca 2ϩ dynamics and transmembrane ionic currents in relation to CMRO 2 in the mouse cerebellar cortex in vivo. We report a direct correlation between CMRO 2 and summed (i.e., the sum of excitatory, negative currents during the whole stimulation period) field EPSCs (ΑfEPSCs) in Purkinje cells (PCs) in response to stimulation of the climbing fiber (CF) pathway. Blocking stimulus-evoked rises in cytosolic Ca 2ϩ in PCs with the P/Q-type channel blocker -agatoxin-IVA (-AGA), or the GABA A receptor agonist muscimol, did not lead to a time-locked reduction in CMRO 2 , and excitatory synaptic or action potential currents. During stimulation, neither -AGA or (-oxo)-bis-(transformatotetramine-ruthenium) (Ru360), a mitochondrial Ca 2ϩ uniporter inhibitor, affected the ratio of CMRO 2 to fEPSCs or evoked local field potentials. However, baseline CBF and CMRO 2 decreased gradually with Ru360. Our data suggest that in vivo activity-dependent rises in CMRO 2 are correlated with synaptic currents and postsynaptic spiking in PCs. Our study did not reveal a unique role of neuronal cytosolic Ca 2ϩ signals in controlling CMRO 2 increases during CF stimulation.

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Section: Frequency Dependence Of Neuronal Camentioning

confidence: 99%

Section: Electrophysiological Recordingsmentioning

confidence: 99%

Section: Csd Calculationmentioning

confidence: 99%

Section: Csd Calculationmentioning

confidence: 99%

See 2 more Smart Citations

Activity-dependent Increases in Local Oxygen Consumption Correlate with Postsynaptic Currents in the Mouse CerebellumIn Vivo

Mathiesen¹,

Caesar²,

Thomsen³

et al. 2011

J. Neurosci.

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“…Purkinje cells exhibit two different types of spikes depending on the source of the afferent input (Llinas, 1981). Complex spikes are elicited by input from the climbing fibers of the inferior olive.…”

mentioning

confidence: 99%

Developmental changes in eyeblink conditioning and simple spike activity in the cerebellar cortex

Nicholson

Freeman

2003

Developmental Psychobiology

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The activity of neurons in the cerebellum exhibits learning-related changes during eyeblink conditioning in adult mammals. The induction and preservation of learning-related changes in cerebellar neuronal activity in developing rats may be affected by the level of maturity in cerebellar feedback to its brainstem afferents, including the inferior olive. Developmental changes in cerebellar plasticity were examined by recording the activity of Purkinje cells in eye regions of cerebellar cortical lobule HVI (lobulus simplex) in infant rats during eyeblink conditioning. The percentage and amplitude of eyeblink conditioned responses increased as a function of age. Analyses of Purkinje cell simple spike activity revealed developmental increases in the number of units that exhibited stimulus-evoked and learning-related changes in activity. Moreover, the magnitude of these changes exhibited a substantial age-related increase. The results support the view that the emergence of learning-specific cerebellar plasticity and the ontogeny of eyeblink conditioning are influenced by developmental changes in the synaptic interactions within brainstem-cerebellum circuits.

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