State-dependent plasticity of the corticostriatal pathway.
Plasticity at corticostriatal synapses is thought to underlie both normal and aberrant forms of reinforcement-driven learning. Studies in brain slices have found bidirectional, spike-timing dependent plasticity in striatum; however it is not known whether similar rules govern corticostriatal plasticity in awake behaving animals. To assess whether behavioral state is a key regulator of plasticity in this pathway, we examined the effects of 5 Hz cortical stimulation trains on evoked striatal field potentials, in either anesthetized or awake, unrestrained rats. Consistent with prior studies we observed long-term potentiation in intact, barbiturate-anesthetized animals. However, when an identical stimulation pattern was applied to the same animals while awake, long-term depression was observed instead. Our results demonstrate that the rules governing corticostriatal plasticity depend critically on behavioral state, and suggest that the dynamic context of cortical-basal ganglia loops must be considered while investigating synaptic mechanisms underlying reinforcement learning and neurological disorders.
Stoetzner
C R
CR
Department of Psychology, and Neuroscience Program, University of Michigan, Ann Arbor, MI 48109-1109, USA.
Pettibone
J R
JR
Berke
J D
JD
D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D001463:Barbiturates / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects* / Q000502:physiology; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D005071:Evoked Potentials / Q000187:drug effects; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology; D036881:Long-Term Synaptic Depression / Q000502:physiology; D008297:Male; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D014851:Wakefulness / Q000502:physiology
D000777:Anesthetics; D001463:Barbiturates; C032232:barbituric acid