While most cortical plasticity studies exposed animals to pulsed tones, studies of IC plasticity used either noise or a continuous tone. Here we compared the effects of repeated exposure to single-frequency tone pips on cortical and

IC frequency representations in juvenile rats. We found that while tone exposure caused a long-lasting increase in cortical representations of the exposure frequency, changes to IC neurons were limited to a transient narrowing of tuning bandwidth. These results suggest that previously documented cortical frequency map reorganization does not depend on similar changes in the subcortical auditory nuclei. (C) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.”
“In this study we SRT1720 in vitro analyze the effect of working memory capacity on the evolution of cooperation and show a case in which societies with strongly limited YM155 molecular weight memory achieve higher levels of cooperation than societies with larger memory. Agents in our evolutionary model are arranged on a network and interact in a prisoner’s dilemma with their neighbors. They learn from

their own experience and that of their neighbors in the network about the past behavior of others and use this information when making their choices. Each agent can only process information from her last h interactions. We show that if memory (h) is too short, cooperation does not emerge in the long run. A slight increase of memory length to around 5-10 periods, though, can lead to largely cooperative societies. Longer memory, on the other hand, is detrimental to cooperation in our model. (C) 2012 Elsevier Ltd. All rights reserved.”
“It is known that dopamine (DA) D1 receptor activation stimulates striatal nitric oxide (NO) synthesis, whereas D2 receptor activation produces the opposite effect. However, the mechanisms involved in the dopaminergic modulation of nitric oxide synthase (NOS) are unknown.

We hypothesized that the effects of DA on striatal NO signaling are dependent on ongoing glutamatergic activation of NOS. Therefore, the current study examined whether intact N-methyl-d-aspartic acid (NMDA) receptor activation

is required for the dopaminergic modulation much of NOS activity.

We assessed the impact of pharmacological manipulations of D1, D2, and NMDA receptors on NOS activity in the dorsal striatum and motor cortex using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Drugs were administered systemically to conscious animals and NADPH-d staining was quantified in these regions using ex vivo measurements of tissue optical density.

Administration of the neuronal NOS inhibitor N (G)-propyl-l-arginine (NPA), the D1 receptor antagonist SCH 23390, and the NMDA receptor antagonist 3-phosphonopropyl-piperazine-2-carboxylic acid (CPP) all attenuated staining selectively in the striatum. Administration of the D2 receptor agonist quinpirole decreased NADPH-d staining in both the striatum and cortex.