Adjusting Behavior to Context: Striatal Network Functions in Learning and Memory
The basal ganglia have been implicated in the neural basis of procedural learning and habit formation both on the basis of clinical and experimental studies.1–6 It is likely that the basal ganglia participate in such learning and memory mechanisms by influencing activity in cortico-basal ganglia circuits that link the neocortex and underlying structures of the basal ganglia. The striatum sits at a key point in these cortico-basal ganglia loops. The striatum is the largest input structure of the basal ganglia, and it is neurons of the striatum that give rise to the largest output pathways of the basal ganglia. Most of the neurons in the striatum are both input and output neurons. It is thought that patterns of convergent and divergent corticostriatal projection may be critical to the processing of information in the striatum. For example, functionally related zones in the cortex can send inputs convergently to corresponding zones in the striatum, and this projection pattern can occur in multiple such zones within the striatum. This widespread and yet compartmentalized system of input connectivity of the striatum is matched in the patterns of projection of striatal output neurons to the output nuclei of the striatum, the pallidum and substantia nigra. The input-output compartments of the striatum (known as striosomes and matrisomes) may confer on the striatum the capacity to reorganize cortical (and other) inputs to this structure. The resorting and recombining of information that occurs may depend critically on patterns of coordinate activation of particular sets of inputs.2, 7
KeywordsBasal Ganglion Conditioning Stimulus Cholinergic Interneuron Habituation Training Matrix Compartment
Unable to display preview. Download preview PDF.
- 15.P. Blazquez, J. Kojima, N. Fujii, R. Courtemanche & A. Graybiel, Aversive conditioning and habituation as well as reward conditioning modify the activity of tonically active neurons in the macaque striatum, Soc. Neurosci. Abstr. 26, 683 (2000).Google Scholar
- 16.P. Blazquez, N. Fujii, W. DeCoteau & A. Graybiel, Tonically active neurons in the primate striatum have responses that correlate with the probability of behavioral response in reward and aversive Pavlovian conditioning and habituation., Soc. Neurosci. Abstr., in press. (2001).Google Scholar