Journal Article

Memory trace and timing mechanism localized to cerebellar Purkinje cells

Rasmussen, Anders, Hesslow, Germund, Zucca, Riccardo, Johansson, Fredrik, Jirenhed, Dan-Anders

2014

Overview

Significance The standard view of neural signaling is that a neuron can influence its target cell by exciting or inhibiting it. An important aspect of the standard view is that learning consists of changing the efficacy of synapses, either strengthening (long-term potentiation) or weakening (long-term depression) them. In studying how cerebellar Purkinje cells change their responsiveness to a stimulus during learning of conditioned responses, we have found that these cells can learn the temporal relationship between two paired stimuli. The cells learn to respond at a particular time that reflects the time between the stimuli. This finding radically changes current views of both neural signaling and learning. The standard view of the mechanisms underlying learning is that they involve strengthening or weakening synaptic connections. Learned response timing is thought to combine such plasticity with temporally patterned inputs to the neuron. We show here that a cerebellar Purkinje cell in a ferret can learn to respond to a specific input with a temporal pattern of activity consisting of temporally specific increases and decreases in firing over hundreds of milliseconds without a temporally patterned input. Training Purkinje cells with direct stimulation of immediate afferents, the parallel fibers, and pharmacological blocking of interneurons shows that the timing mechanism is intrinsic to the cell itself. Purkinje cells can learn to respond not only with increased or decreased firing but also with an adaptively timed activity pattern.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Animals / Basic Medicine / Behavioral neuroscience / Biological Sciences / cell communication / Cells / Cerebellar cortex / Cerebellum - cytology / Conditioning (Psychology) - drug effects / Educational conditioning / Electric Stimulation / Ferrets - physiology / Fibers / Horizontal bar / Interneurons / Learning / Male / Medical and Health Sciences / Medicin och hälsovetenskap / Medicinska och farmaceutiska grundvetenskaper / Memory / Memory - drug effects / Memory - physiology / Memory trace / Mustela putorius furo / Neural Inhibition - drug effects / Neurons / Neuroscience / Neurosciences / Neurovetenskaper / Purkinje cells / Purkinje Cells - drug effects / Purkinje Cells - physiology / Pyridazines - pharmacology / synapse / Synapses / Time Factors