Selective Engagement of Plasticity Mechanisms for Motor Memory Storage

Abstract

The number and diversity of plasticity mechanisms in the brain raises a central question: does a neural circuit store all memories by stereotyped application of the available plasticity mechanisms, or can subsets of these mechanisms be selectively engaged for specific memories? The uniform architecture of the cerebellum has inspired the idea that plasticity mechanisms like cerebellar long-term depression (LTD) contribute universally to memory storage. To test this idea, we investigated a set of closely related, cerebellum-dependent motor memories. In mutant mice lacking Ca(2+)/calmodulin-dependent protein kinase IV (CaMKIV), the maintenance of cerebellar LTD is abolished. Although memory for an increase in the gain of the vestibulo-ocular reflex (VOR) induced with high-frequency stimuli was impaired in these mice, memories for decreases in VOR gain and increases in gain induced with low-frequency stimuli were intact. Thus, a particular plasticity mechanism need not support all cerebellum-dependent memories, but can be engaged selectively according to the parameters of training.

Transient Receptor Potential Canonical Channels Regulate the Induction of Cerebellar Long-Term Depression

“…Our data have shown that TRPC3 is required for the induction of cerebellar LTD, which has long been considered as the molecular basis of motor coordination and cerebellar motor learning (Aiba et al, 1994;Kim and Thompson, 1997;De Zeeuw et al, 1998;Feil et al, 2003;Boyden et al, 2006;Hansel et al, 2006). Specifically in TRPC3 knock-out mice, the walking behavior and sEPSC induced through the brief burst of a PF stimulus are impaired (Hartmann et al, 2008).…”

Timing Rules for Synaptic Plasticity Matched to Behavioral Function

“…Long-term associative plasticity in the flocculus in vitro: Temporal requirements matched to behavioral function Our finding that coincident parallel fiber and climbing fiber stimulation failed to induce LTD in the flocculus was surprising, given the multiple lines of evidence for a role of climbing fiber-triggered LTD in flocculus-dependent learning (e.g., Boyden et al, 2006;Hansel et al, 2006;Ito, 2001;Kimpo et al, 2014;Medina and Lisberger, 2008). However, in vivo, the activation of climbing fibers by performance errors would be delayed relative to the parallel fiber activity that caused the error, rather than coincident.…”

Acute inhibition of estradiol synthesis impacts vestibulo-ocular reflex adaptation and cerebellar long-term potentiation in male rats

“…For the VOR adaptation the conditioning stimuli consisted of turntable and drum sinusoidal oscillations on the vertical axis in the light (Boyden et al 2006;Kimpo et al 2005). Two different sets of oscillation parameters were used to induce VOR decrease (gain-down conditioning) and increase (gain-up conditioning), respectively (Fig.…”