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The mechanism through which the brain senses the metabolic state, enabling an animal to regulate food consumption, and discriminate between nutritional and non-nutritional foods is a fundamental question. Flies choose the sweeter non-nutritive sugar, L-glucose, over the nutritive D-glucose if they are not starved. However, under starvation conditions, they switch their preference to D-glucose, and this occurs independent of peripheral taste neurons. Here, we found that eliminating the TRPγ channel impairs the ability of starved flies to choose D-glucose. This food selection depends on trpγ expression in neurosecretory cells in the brain that express diuretic hormone 44 (DH44). Loss of trpγ increases feeding, alters the physiology of the crop, which is the fly stomach equivalent, and decreases intracellular sugars and glycogen levels. Moreover, survival of starved trpγ flies is reduced. Expression of trpγ in DH44 neurons reverses these deficits. These results highlight roles for TRPγ in coordinating feeding with the metabolic state through expression in DH44 neuroendocrine cells. more...

Primary visual cortex (V1) in the mouse projects to numerous brain areas, including several secondary visual areas, frontal cortex, and basal ganglia. While it has been demonstrated that optogenetic silencing of V1 strongly impairs visually guided behavior, it is not known which downstream areas are required for visual behaviors. Here we trained mice to perform a contrast-increment change detection task, for which substantial stimulus information is present in V1. Optogenetic silencing of visual responses in secondary visual areas revealed that their activity is required for even this simple visual task. In vivo electrophysiology showed that, although inhibiting secondary visual areas could produce some feedback effects in V1, the principal effect was profound suppression at the location of the optogenetic light. The results show that pathways through secondary visual areas are necessary for even simple visual behaviors. more...

Many cortical network models use recurrent coupling strong enough to require inhibition for stabilization. Yet it has been experimentally unclear whether inhibition-stabilized network (ISN) models describe cortical function well across areas and states. Here, we test several ISN predictions, including the counterintuitive (paradoxical) suppression of inhibitory firing in response to optogenetic inhibitory stimulation. We find clear evidence for ISN operation in mouse visual, somatosensory, and motor cortex. Simple two-population ISN models describe the data well and let us quantify coupling strength. Although some models predict a non-ISN to ISN transition with increasingly strong sensory stimuli, we find ISN effects without sensory stimulation and even during light anesthesia. Additionally, average paradoxical effects result only with transgenic, not viral, opsin expression in parvalbumin (PV)-positive neurons; theory and expression data show this is consistent with ISN operation. Taken together, these results show strong coupling and inhibition stabilization are common features of the cortex. more...

Objective: To examine whether maternal depressed mood at birth moderated the protective effect of a home-visiting intervention on the quality of caregiving for children growing up in a low- and middle-income country., Method: Almost all pregnant mothers in 24 Cape Town neighborhoods were recruited into a cluster randomized controlled trial matched by neighborhoods to the Philani home-visiting condition (HVC) or the standard care condition (SC). At 3 years after birth, the quality of mother-child interactions between HVC and SC mothers with and without antenatal depressed mood was assessed in a representative subset by rating videotaped observations of mother-child interactions on 10 dimensions of caregiving., Results: As predicted, maternal depressed mood at birth moderated the effect of the HVC on the quality of mother-child interactions. Among nondepressed mothers, mothers and their children in the HVC scored significantly higher on 5 of the 10 dimensions of the maternal-child interaction scale than mothers in the SC: mothers exhibited more maternal sensitivity, talked more, had more harmonious interactions, and had children who paid more attention and exhibited more positive affect. However, being in the HVC did not significantly affect the mother-child interaction scores among mothers with depressed mood. Among HVC children, those with mothers with depressed mood showed significantly less positive affect and talked less with their mothers than children with nondepressed mothers. SC children with mothers with depressed mood were more responsive and paid attention to their mothers than children with nondepressed mothers., Conclusion: Home visiting resulted in a better quality of caregiving for mothers without depressive symptoms. Future interventions need to specifically target maternal depression and positive mother-child interactions., Clinical Trial Registration Information: Mentor Mothers: A Sustainable Family Intervention in South African Townships; https://clinicaltrials.gov; NCT00972699; Philani Home-based Nutrition Intervention Program; https://clinicaltrials.gov; NCT00995592., (Copyright © 2019 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.) more...