Decision making is a multifaceted process, consisting of several distinct phases that likely require different cognitive operations. Previous work showed that the basolateral amygdala (BLA) is a critical substrate for decision making involving risk of punishment; however, it is unclear how the BLA is recruited at different stages of the decision process. To this end, the current study used optogenetics to inhibit the BLA during specific task phases in a model of risky decision making (risky decision-making task) in which rats choose between a small, "safe" reward and a large reward accompanied by varying probabilities of footshock punishment. Male Long-Evans rats received intra-BLA microinjections of viral vectors carrying either halorhodopsin (eNpHR3.0-mCherry) or mCherry alone (control) followed by optic fiber implants and were trained in the risky decision-making task. Laser delivery during the task occurred during intertrial interval, deliberation, or reward outcome phases, the latter of which was further divided into the three possible outcomes (small, safe; large, unpunished; large, punished). Inhibition of the BLA selectively during the deliberation phase decreased choice of the large, risky outcome (decreased risky choice). In contrast, BLA inhibition selectively during delivery of the large, punished outcome increased risky choice. Inhibition had no effect during the other phases, nor did laser delivery affect performance in control rats. Collectively, these data indicate that the BLA can either inhibit or promote choice of risky options, depending on the phase of the decision process in which it is active. To date, most behavioral neuroscience research on neural mechanisms of decision making has used techniques that preclude assessment of distinct phases of the decision process. Here we show that optogenetic inhibition of the BLA has opposite effects on choice behavior in a rat model of risky decision making, depending on the phase in which inhibition occurs. BLA inhibition during a period of deliberation between small, safe and large, risky outcomes decreased risky choice. In contrast, BLA inhibition during receipt of the large, punished outcome increased risky choice. These findings highlight the importance of temporally targeted approaches to understand neural substrates underlying complex cognitive processes. More importantly, they reveal novel information about dynamic BLA modulation of risky choice.

Social recognition, the ability to recognize individuals that were previously encountered, requires complex integration of sensory inputs with previous experience. Here, we use a variety of approaches to discern how oxytocin-sensitive neurons in the PFC exert descending control over a circuit mediating social recognition in mice. Using male mice with Cre-recombinase directed to the oxytocin receptor gene (Oxtr), we revealed that oxytocin receptors (OXTRs) are expressed on glutamatergic neurons in the PFC, optogenetic stimulation of which elicited activation of neurons residing in several mesolimbic brain structures. Optogenetic stimulation of axons in the BLA arising from OXTR-expressing neurons in the PFC eliminated the ability to distinguish novel from familiar conspecifics, but remarkably, distinguishing between novel and familiar objects was unaffected. These results suggest that an oxytocin-sensitive PFC to BLA circuit is required for social recognition. The implication is that impaired social memory may manifest from dysregulation of this circuit.

No abstract

Inhibition of both Rho kinase (ROCK-I) and NADPH oxidase (NOX2) to treat neuroinflammation could be very effective in the treatment of progressive neurological diseases like Alzheimer's disease, autism spectral disorder, and fragile X syndrome. NOX2 being a multi-enzyme component is activated during host defense in phagocytes such as microglia, to catalyze the production of superoxide from oxygen, while ROCK is an important mediator of fundamental cell processes like adhesion, proliferation and migration. Phosphorylated ROCK was found to activate NOX2 assembly via Ras related C3 botulinum toxin substrate (Rac) in disease conditions. Overexpression of ROCK-I and NOX2 in innate immune cells like microglial cells contribute to progressive neuronal damage early in neurological disease development. In the present study we employed a computer-aided methodology combining pharmacophores and molecular docking to identify new chemical entities that could inhibit ROCK-I as well as NOX2 (p47 phox). Among the huge dataset of a commercial database, top 18 molecules with crucial binding interactions were selected for biological evaluation. Seven among the lead molecules exhibited inhibitory potential against ROCK-I and NOX2 with IC50s ranging from 1.588 to 856.2 nM and 0.8942 to 10.24 μM, respectively, and emerged as potential hits as dual inhibitors with adequate selectivity index (SI = CC50/GIC50) in cell-based assays. The most active compound 3 was further found to show reduction of the pro-inflammatory mediators such as TNFα, interleukin-6 (IL-6) and interleukin-1beta (IL-1β) mRNA expression levels in activated (MeHg treated) human neuroblastoma (IMR32) cell lines. Hence the present work documented the utility of these dual inhibitors as prototypical leads to be useful for the treatment of neurological disorders including autism spectrum disorder and Alzheimer's disease.