Experience-dependent plasticity of gustatory insular cortex circuits and taste preferences.

Early experience with food influences taste preference in adulthood. How gustatory experience influences development of taste preferences and refinement of cortical circuits has not been investigated. Here, we exposed weanling mice to an array of taste solutions and determined the effects on the preference for sweet in adulthood.

An Insula-Central Amygdala Circuit for Guiding Tastant-Reinforced Choice Behavior.

For animals to survive, they must reliably predict during foraging which substances are suitable for consumption. Despite extensive study, the neural circuit mechanisms underlying such adaptive behavior remain poorly understood. Here, using a tastant (sucrose/quinine)-reinforced "go/no-go" task in male and female mice, we examined the anatomical and functional connectivity of the circuit linking the insular cortex (IC) to the central amygdala (CeA) and the role of this circuit in the establishment of appropriate behavioral responses.

Characterization of the amplificatory effect of norepinephrine in the acquisition of Pavlovian threat associations.

The creation of auditory threat Pavlovian memory requires an initial learning stage in which a neutral conditioned stimulus (CS), such as a tone, is paired with an aversive one (US), such as a shock. In this phase, the CS acquires the capacity of predicting the occurrence of the US and therefore elicits conditioned defense responses. Norepinephrine (NE), through β-adrenergic receptors in the amygdala, enhances threat memory by facilitating the acquisition of the CS-US association, but the nature of this effect has not been described.

Primary auditory cortex regulates threat memory specificity.

Distinguishing threatening from nonthreatening stimuli is essential for survival and stimulus generalization is a hallmark of anxiety disorders. While auditory threat learning produces long-lasting plasticity in primary auditory cortex (Au1), it is not clear whether such Au1 plasticity regulates memory specificity or generalization. We used muscimol infusions in rats to show that discriminatory threat learning requires Au1 activity specifically during memory acquisition and retrieval, but not during consolidation.

β-Adrenergic Receptors Regulate the Acquisition and Consolidation Phases of Aversive Memory Formation Through Distinct, Temporally Regulated Signaling Pathways.

Memory formation requires the temporal coordination of molecular events and cellular processes following a learned event. During Pavlovian threat (fear) conditioning (PTC), sensory and neuromodulatory inputs converge on post-synaptic neurons within the lateral nucleus of the amygdala (LA). By activating an intracellular cascade of signaling molecules, these G-protein-coupled neuromodulatory receptors are capable of recruiting a diverse profile of plasticity-related proteins.

Molecular mechanisms of threat learning in the lateral nucleus of the amygdala.

Pavlovian threat conditioning is a behavioral paradigm that has been successfully utilized to define the mechanisms underlying threat (fear) memory formation. The amygdala is a temporal lobe structure required for the acquisition, consolidation, and expression of threat (fear) memories. In particular, the lateral nucleus of the amygdala (LA) is the major input structure of the amygdala and is required for all aspects of threat learning and memory.

Rhesus monkey alpha7 nicotinic acetylcholine receptors: comparisons to human alpha7 receptors expressed in Xenopus oocytes.

An alpha7 nicotinic acetylcholine receptor sequence was cloned from Rhesus monkey (Macaca mulatta). This clone differs from the mature human alpha7 nicotinic acetylcholine receptor in only four amino acids, two of which are in the extracellular domain. The monkey alpha7 nicotinic receptor was characterized in regard to its functional responses to acetylcholine, choline, cytisine, and the experimental alpha7-selective agonists 4OH-GTS-21, TC-1698, and AR-R17779.

Molecular dissection of tropisetron, an alpha7 nicotinic acetylcholine receptor-selective partial agonist.

The alpha7 nicotinic acetylcholine receptor (nAChR)-selective partial agonist tropisetron is a conjugate of an indole and a tropane group. We tested compounds structurally related to either the indole or tropane domains of tropisetron on oocytes expressing human alpha7. alpha4beta2, or alpha3beta4 nAChR or rat 5HT(3A) receptors.

Tolerance for inequity may increase with social closeness in chimpanzees.

Economic decision-making depends on our social environment. Humans tend to respond differently to inequity in close relationships, yet we know little about the potential for such variation in other species. We examine responses to inequity in several groups of chimpanzees (Pan troglodytes) in a paradigm similar to that used previously in capuchin monkeys (Cebus apella).