Call & A Tomasello, 2005). Fluent social interaction in adult humans implies efficient processing of beliefs, yet direct tests suggest that belief reasoning is cognitively demanding, even for adults (e.g., I. A. Apperly, D. Samson, & G. W. Humphreys, 2009). The authors interpret these findings by drawing an analogy with the domain of number cognition, where similarly contrasting results have been observed.
They propose that the success of infants and nonhuman animals on some belief reasoning tasks may be best explained by a cognitively efficient but inflexible capacity for tracking belief-like states. In humans, this capacity persists in parallel with a later-developing, more flexible but more cognitively demanding theory-of-mind abilities.”
“The bed nucleus of the stria terminalis (BNST) plays a critical role in regulating the behavioral response to selleck kinase inhibitor stress. Stressors that activate the BNST also activate serotonergic (5-HT) systems. Hence, maladaptive
changes of 5-HT receptor expression may contribute to stress-induced anxiety disorders. The BNST contains three neuronal types, Type I-Ill neurons. However, little is known about 5-HT receptor subtypes mRNA expression in these neurons, or whether it can be modulated by stress. Whole-cell patch clamp recording from Type I-Ill neurons was used in conjunction with single cell reverse transcriptase polymerase chain reaction (RT-PCR) to characterize 5-HT receptor mRNA expression, and examine
the effects of stress on this expression. We report that Type I neurons expressed mRNA transcripts predominantly for selleck inhibitor 5-HT1A and 5-HT7 receptors. Type II neurons expressed transcripts for every 5-HT receptor except the 5-HT2C receptor. Type II neurons were divided into three sub-populations: Type IIA in which transcripts for 5-HT3 and 5-HT7 receptors predominate, PDK3 Type IIB that mainly express 5-HT1B and 5-HT4 receptor transcripts, and Type IIC in which transcripts for 5-HT1A and 5-HT2A receptors predominate. Type Ill neurons were also subdivided into two sub-populations; one that predominantly expressed transcripts for 5-HT1A, 5-HT1B and 5-HT2A receptors, and another that mainly expressed transcripts for 5-HT2C receptor. Unpredictable shock stress (USS) caused a long-lasting increase in anxiety-like behavior, and a concomitant decrease in 5-HT1A transcript expression in Type I-III neurons, as well as an up-regulation of a transcriptional repressor of 5-HT1A gene expression, deformed epidermal autoregulatory factor 1 (Deaf-1). Significantly USS decreased 5-HT1A protein level, and increased the level of Deaf-1. USS also increased 5-HT1B transcript expression in Type Ill neurons, as well as 5-HT7 expression in Type I and II neurons. These data suggest that cell type-specific disruption of 5-HT receptor expression in BNSTALG neurons may contribute to stress-induced anxiety disorders. (c) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.