Activity patterns of cerebellar cortical neurones and climbing fibre afferents in the awake cat.

Associative learning in the cerebellum has previously focused on single movements. In eyeblink conditioning, for instance, a subject learns to blink at the right time in response to a conditional stimulus (CS), such as a tone that is repeatedly followed by an unconditional corneal stimulus (US). During conditioning, the CS and US are transmitted by mossy/parallel fibers and climbing fibers to cerebellar Purkinje cells that acquire a precisely timed pause response that drives the overt blink response. The timing of this conditional Purkinje cell response is determined by the CS-US interval and is independent of temporal patterns in the input signal. In addition to single movements, the cerebellum is also believed to be important for learning complex motor programs that require multiple precisely timed muscle contractions, such as, for example, playing the piano. In the present work, we studied Purkinje cells in decerebrate ferrets that were conditioned using electrical stimulation of mossy fiber and climbing fiber afferents as CS and US, while alternating between short and long interstimulus intervals. We found that Purkinje cells can learn double pause responses, separated by an intermediate excitation, where each pause corresponds to one interstimulus interval. The results show that individual cells can not only learn to time a single response but that they also learn an accurately timed sequential response pattern.cerebellum | Purkinje cells | learning | timing | classical conditioning P laying the piano, typing on your keyboard, and uttering a sentence are all typical examples of complex behaviors. Although they involve simple movements as building blocks, they need to be executed with great temporal precision and in a specific sequential order. Utter phonemes in the wrong order or with incorrect timing, and the result is incomprehensible.

show abstract

“…electrically stimulated for 10 ms at 500 Hz as a proxy for the blink-eliciting periocular US (21,22) (Fig. 1C).…”

Section: Significancementioning

confidence: 99%

Learned response sequences in cerebellar Purkinje cells

Jirenhed

Rasmussen

Johansson

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Both in vitro and in vivo, an individual Purkinje neuron maintains a distinct resting firing rate (Armstrong and Rawson, 1979;Häusser and Clark, 1997;Raman and Bean, 1997). A survey across many Purkinje neurons shows that some cells fire as slowly as 5 spikes/sec, whereas others fire as rapidly as 80 spikes/sec.…”

Section: Introductionmentioning

confidence: 99%

Persistent Changes in Spontaneous Firing of Purkinje Neurons Triggered by the Nitric Oxide Signaling Cascade

Smith

Otis

2003

J. Neurosci.

View full text Add to dashboard Cite

Many types of neurons fire spontaneously because of the activity of pacemaking ion channels. Although endogenous firing can serve as a persistent signal to downstream targets, little attention has been paid to factors that might modulate such intrinsic electrical activity. We tested for modulation of spontaneous firing of Purkinje neurons in cerebellar slices under conditions in which principal synaptic inputs were blocked. Loose-patch recordings from single neurons show that sustained (Ͼ40 min) increases in the spontaneous firing rate can be triggered by activation of the nitric oxide-cGMP signaling pathway. Inhibitors of soluble guanylate cyclase and protein kinase G block this modulation. Increases in firing rate are also observed after stimulation of parallel fibers but not in response to basket cell activity. These findings elucidate a novel role for the nitric oxide-cGMP signaling cascade in the brain. This mechanism could permit long-term adjustments in the baseline firing rate of endogenously active neurons in response to changes in afferent activity.

show abstract

“…Although cerebellar Purkinje cell complex spikes occur at low frequency (ϳ1/s), each complex spike is often associated with a high-frequency burst of climbing fiber spikes (Eccles et al, 1966;Armstrong and Rawson, 1979). A Purkinje cell, after being penetrated by a glass microelectrode, often depolarizes to the point at which it no longer generates action potentials (Granit and Phillips, 1956;Eccles et al, 1966).…”

Section: Introductionmentioning

confidence: 99%

“…A Purkinje cell, after being penetrated by a glass microelectrode, often depolarizes to the point at which it no longer generates action potentials (Granit and Phillips, 1956;Eccles et al, 1966). The climbing fiber input is then registered as either a single EPSP or more usually as a compound EPSP composed of multiple EPSPs separated from each other by ϳ2 ms (Eccles et al, 1966;Armstrong and Rawson, 1979). The amplitude and polarity of these compound EPSPs can be manipulated by changing the membrane potential (Eccles et al, 1966;Simpson et al, 1974), and the spike-generating mechanism can be restored by hyperpolarizing the cell (Eccles et al, 1966).…”

Section: Introductionmentioning

confidence: 99%

Intraburst and Interburst Signaling by Climbing Fibers

Maruta

Hensbroek²,

Simpson³

2007

J. Neurosci.

View full text Add to dashboard Cite

Although cerebellar Purkinje cell complex spikes occur at low frequency (ϳ1/s), each complex spike is often associated with a highfrequency burst (ϳ500/s) of climbing fiber spikes. We examined the possibility that signals are present within the climbing fiber bursts. By intracellularly recording from depolarized, nonspiking Purkinje cells in anesthetized pigmented rabbits, climbing fiber burst patterns were investigated by determining the number of components in the induced compound EPSPs during spontaneous activity and during visual stimulation. For our sample of 43 cells, Ͼ70% of all EPSPs were of the compound type composed of two or three EPSPs. During spontaneous activity, the number of components in each compound EPSP was not related to the latency to the succeeding compound EPSP. Conversely, the number of components in each compound EPSP was related to its latency after the preceding compound EPSP. This latency increased from 0.62 s for one-component EPSPs to 1.69 s for compound EPSPs with four or more components. The effect of visual stimulation on the climbing fiber activity was studied in 19 floccular Purkinje cells whose low-frequency interburst climbing fiber response was modulated by movement about the vertical axis. During sinusoidal oscillation (0.1 Hz, Ϯ10°), compound EPSPs with a larger number of components tended to be more prevalent during movement in the excitatory direction than in the inhibitory direction. Thus, climbing fibers can, in addition to modulation of their low interburst frequency, transmit signals in the form of the number of spikes within each high-frequency burst.

show abstract

Activity patterns of cerebellar cortical neurones and climbing fibre afferents in the awake cat.

Cited by 257 publications

References 32 publications

Learned response sequences in cerebellar Purkinje cells

Learned response sequences in cerebellar Purkinje cells

Persistent Changes in Spontaneous Firing of Purkinje Neurons Triggered by the Nitric Oxide Signaling Cascade

Intraburst and Interburst Signaling by Climbing Fibers

Contact Info

Product

Resources

About