* Corresponding author. E-mail address: volker@bbf.uia.ac.be (V. Steuber). Neurocomputing 38}40 (2001) 383}388 Long-term depression and recognition of parallel "bre patterns in a multi-compartmental model of a cerebellar Purkinje cell Volker Steuber*, Erik De Schutter Laboratory for Theoretical Neurobiology, Born-Bunge Foundation, University of Antwerp, B-2610 Antwerp, Belgium Abstract It has been suggested that long-term depression (LTD) of parallel "bre (PF) synapses enables a cerebellar Purkinje cell (PC) to learn to recognise PF activity patterns. We investigate the recognition of PF patterns that have been stored by LTD of AMPA receptors in a multi- compartmental PC model with a passive soma. We "nd that a corresponding arti"cial neural network outperforms a PC model with active dendrites by an order of magnitude. Removal of the dendritic ion channels leads to a further decrease in performance. Another e!ect of the active dendrites is an afterhyperpolarization response to novel PF patterns. Thus, the LTD based storage of PF patterns can lead to a potentiated late PC response.  2001 Elsevier Science B.V. All rights reserved. Keywords: Cerebellum; Purkinje cells; LTD; Pattern recognition; Learning 1. Introduction One of the most contentious issues in cerebellar research is whether or not long-term depression (LTD) of parallel "bre evoked excitatory postsynaptic poten- tials (epsps) in Purkinje cells is the substrate of learning in the cerebellar cortex (e.g. [3]). LTD can be induced by repeated conjuctive parallel "bre (PF) and climbing "bre (CF) input to the Purkinje cell [8]. It has been suggested that a PF pattern that is repeatedly paired with CF input elicits a reduced Purkinje cell response, leading to 0925-2312/01/$-see front matter  2001 Elsevier Science B.V. All rights reserved. PII:S0925-2312(01)00458-1