To understand

the role of the striatum in value- and strategy-based decision-making, we recorded striatal neurons in macaque monkeys performing a behavioral task in which they searched for a reward target by trial-and-error among three alternatives, earned a reward for a target choice, and then earned additional rewards for choosing the same target. This task allowed us to examine whether and how values of targets and strategy, which were defined as negative-then-search and positive-then-repeat (or win-stay-lose-switch), selleck compound are represented in the striatum. Large subsets of striatal neurons encoded positive and negative outcome feedbacks of individual decisions and actions. Once monkeys made a choice, signals related http://www.selleckchem.com/products/sch-900776.html to chosen actions, their values and search- or repeat-type actions increased and persisted until the outcome feedback appeared. Subsets of neurons exhibited a tonic increase in activity after the search- and repeat-choices following negative and positive feedback in the last trials as the task strategy monkeys adapted. These activity profiles as a heterogeneous representation of decision variables may underlie a part of the process for reinforcement- and strategy-based evaluation of selected actions

in the striatum. “
“In the last few years it has become clear that AMPA-type glutamate neurotransmitter receptors are rapidly transported into and out of synapses to strengthen or weaken their function. The remarkable dynamics of AMPA receptor (AMPAR) synaptic localization provides a compelling mechanism for understanding the cellular basis of learning and memory, as well as disease states involving cognitive dysfunction. Here, we summarize the evidence for AMPAR trafficking

as a mechanism underlying a variety of learned responses derived from both behavioral and P-type ATPase cellular studies. Evidence is also reviewed supporting synaptic dysfunction related to impaired AMPAR trafficking as a mechanism underlying learning and memory deficits in Alzheimer’s disease. We conclude that emerging data support the concept of multistage AMPAR trafficking during learning and that a broad approach to include examination of all of the AMPAR subunits will provide a more complete view of the mechanisms underlying multiple forms of learning. “
“Recent studies have shown a continued maturation of visual responsiveness and synaptic activity of retina after eye opening, including the size of receptive fields of retinal ganglion cells (RGCs), light-evoked synaptic output of RGCs, bipolar cell spontaneous synaptic inputs to RGCs, and the synaptic connections between RGCs and ON and OFF bipolar cells. Light deprivation retarded some of these age-dependent changes. However, many other functional and morphological features of RGCs are not sensitive to visual experience.