Details

Autor(en) / Beteiligte

• Bosman, Laurens W. J.
• Koekkoek, Sebastiaan K. E.
• Shapiro, Joël
• Rijken, Bianca F. M.
• Zandstra, Froukje
• Van Der Ende, Barry
• Owens, Cullen B.
• Potters, Jan‐Willem
• De Gruijl, Jornt R.
• Ruigrok, Tom J. H.
• De Zeeuw, Chris I.

Titel

Encoding of whisker input by cerebellar Purkinje cells

Ist Teil von

• The Journal of physiology, 2010-10, Vol.588 (19), p.3757-3783

Ort / Verlag

Oxford, UK: Blackwell Publishing Ltd

Erscheinungsjahr

2010

Quelle

Access via Wiley Online Library

Beschreibungen/Notizen

• The cerebellar cortex is crucial for sensorimotor integration. Sensorimotor inputs converge on cerebellar Purkinje cells via two afferent pathways: the climbing fibre pathway triggering complex spikes, and the mossy fibre–parallel fibre pathway, modulating the simple spike activities of Purkinje cells. We used, for the first time, the mouse whisker system as a model system to study the encoding of somatosensory input by Purkinje cells. We show that most Purkinje cells in ipsilateral crus 1 and crus 2 of awake mice respond to whisker stimulation with complex spike and/or simple spike responses. Single‐whisker stimulation in anaesthetised mice revealed that the receptive fields of complex spike and simple spike responses were strikingly different. Complex spike responses, which proved to be sensitive to the amplitude, speed and direction of whisker movement, were evoked by only one or a few whiskers. Simple spike responses, which were not affected by the direction of movement, could be evoked by many individual whiskers. The receptive fields of Purkinje cells were largely intermingled, and we suggest that this facilitates the rapid integration of sensory inputs from different sources. Furthermore, we describe that individual Purkinje cells, at least under anaesthesia, may be bound in two functional ensembles based on the receptive fields and the synchrony of the complex spike and simple spike responses. The ‘complex spike ensembles’ were oriented in the sagittal plane, following the anatomical organization of the climbing fibres, while the ‘simple spike ensembles’ were oriented in the transversal plane, as are the beams of parallel fibres. The rodent whisker system, combining simple movements with prompt sensory feedback, is generally considered as a model system to study integration of sensory and motor information. Although the cerebellum is critically important for this ‘sensorimotor integration’, hardly any functional data on its whisker representation is available. We show that Purkinje cells, which form the sole output of the cerebellar cortex, cooperate in functional groups to encode the amplitude, speed and direction of mechanical whisker stimulations. The two nervous pathways conveying input to the cerebellar cortex, the mossy fibre and the climbing fibre pathway, mediate different aspects of sensory input. Specifically, mossy fibre inputs convey information from multiple whiskers and are insensitive to the direction of whisker movement, while climbing fibres encode in a direction‐specific way the movement of a single whisker. Thus, this study contributes to our understanding of how sensory input is distributed over and encoded by the cerebellar cortex.